Sample Vial Silanization And Cleaning Method

HAWACH sample vial is produced following the international standard under strict production environment, thus no worries about the product quality issue.

The 9mm sample vial was designed by instrument manufacturers in Europe and the United States. It is featured with universal and easy to grasp, especially the use of automatic system, thus this vial is also called automatic injection vial. Also this sample vial is highly compatible: the 11.6mm sample vial can almost be replaced by 9mm for for use.

To be honest, this sample vial has an important defect. As the thread is short and the gasket is thin, which is easy to puncture and also increases the injection risk.

Silanization
Sample vial after silanization can reduce the adsorption of polar samples on the inner wall of the glass; some compounds, such as amino acids, proteins, or phenolic compounds, even in f-grade hydrolyzed glass commonly used for chromatographic analysis, have various degrees of adsorption. Surface on silanized glass will be deactivated to eliminate reactions between polar samples and glass.

Sample vial five kinds of cleaning method

Method one:
1. Clean the liquid in the sample bottle;
2. Then pour in almost full alcohol, wash it twice with ultrasonic, and then pour it clean, because alcohol is easy to enter into 1.5ml small bottle, and compatible with most organic solvents;
3. Pour clear water into the sample vial and wash it with ultrasonic twice 4. Pour out the washing solution in the sample vial and dry it at 110 ℃ for 1-2 hours. It is not allowed to bake it under high temperature, which is easy to damage the sample bottle;
5. Cooling and preservation.

Method two:
1. Rinse with tap water several times;
2. Put it into a beaker filled with pure water and ultrasound for 15 minutes 3. Change water and ultrasound for another 15 minutes;
4. Sample vail soak in a beaker filled with anhydrous ethanol;
5. Take out and air dry.

Method three:
1. Soak it in methanol, wash it with ultrasonic for 20 minutes, and then drain it; 2. Fill the sample vial with water, wash it with ultrasonic for 20 minutes, and then drain the water;
3. Then dry the sample bottle.

Method four:
1. It is generally washed and dried with clear water and then soaked with potassium dichromate sulfate lotion;
2. The washing method of the sample vial is the same as that of the solution. First, soak the sample vial with medical alcohol for more than 4 hours, then ultrasound for half an hour, then pour out the medical alcohol, ultrasound for half an hour with water, and then dry it with water.

Method five:
1. If the funds are enough, it is better to buy a new sample vial for cleaning;
2. If it is to be reused, the cleaning method is particularly important. First, soak it in strong oxidation cleaning solution (potassium dichromate) for 24 hours, then clean it three times with deionized water under ultrasonic condition, and finally clean it once with methanol, then dry it for use ;
3. During the analysis, the vial pad should be replaced with a new one, especially after the analysis of agricultural products, or the analysis results will be affected.

Sample Vial Silanization And Cleaning Method

Operation Tips And Some Details Of Flash Column

The flash chromatography technology is developed since the year of 1978 and applied for the purification of the organic compound. In comparison with traditional column chromatography, the flash chromatography is faster and cheaper.

If you are going to isolate a certain desirable compound, flash column chromatography is a good way to separate the different components of a mixture very effectively by using pressure in the column.

We all know that every component of a mixture has its own particular shape, size, polarity, and solubility. Those distinguishing characteristics can be used by the scientists to isolate and purify each individual component within a mixture.

The isolation can be done in many ways, and the principle is the same as always. The affinity of certain molecules to others will slow down their movement through a medium as while other molecules in the mixture can pass more easily through the medium. Then we can get clear separation and purification of the components from the mixture.

Nowadays we can run the flash columns with compressed air pushing the solvent through the column. HAWACH flash columns will not only help you provide better separation but also save the running time of the separations.

Some Details of Flash Column

In general, flash chromatography is the technology of normal phase liquid chromatographic separation. Sometimes, it also uses reverse-phase silica gel as the filler. However, most of the users are inclined to use silica gel in the flash chromatography.

Column packing consists of wet and dry two kinds. In general, the wet process is the most convenient way to dissolve samples with eluent, dichloromethane, ethyl acetate and so on. The piston at the bottom of the column must not be coated with lubricant, otherwise, it will be brought into the eluent, and the valve of PTFE material can be used. There is no substantial difference between dry and wet packing, as long as the columns can be filled. The packed columns should be moderately tight and be sure to be uniform or the sample will flow diagonally from one side.

Generally, the volumes of sample loading range from milligrams to hectograms and the flow rates are 10 ml/min to 300 ml/min. Mostly, the flash chromatography uses the organic solvent with low and medium polarity as the mobile phase, such as hexane and ethyl acetate. Nowadays, most of the flash columns apply the technology of automatic loading and the column bedding is tight and uniform without the channeling effect. Also, the degree of separation is high and the reproducibility is good.

Furthermore, the normal phase and reverse-phase silica gel fillers of different grain sizes (minimum 15μm) can make the users choose different flash columns according to different requirements of economy and efficiency.

In terms of the raw material for making the flash column, the polypropylene of medical grade is a good choice because it avoids creating pollution to the separated sample. Besides, the transparent column allows the users to observe the condition of sample separation more directly.

Operation Tips And Some Details Of Flash Column

Property And Principle Of Reversed Phase C4 HPLC Column

The properties of the reversed-phase filler are determined by the matrix and the substrate. the particle shape, size, pore size and pore size distribution of the matrix, specific surface area, residual silicon hydroxyl concentration, and the content of impurity ions will all have an effect on the chromatographic behavior of the reversed phase filler. And the type of the ligand, the way of connection, the density of the ligand, etc., determine the retention behavior of the solute. Additionally, reversed phase C4 HPLC column is a chromatographic model based on the hydrophobic effect between the surface of solute, polar mobile phase and nonpolar stationary phase. The structure of any organic molecule has a nonpolar hydrophobic part.

Characteristic of Reversed Phase C4 HPLC Column
Hawach uses highly controllable monolayer formation and tail sealing techniques to produce reversed phase C4 HPLC column. It features high inter-column reproducibility, high selectivity, and separation efficiency. Moreover, it is suitable for the separation of acidic, neutral and alkaline compounds, as well as many drugs and peptides, etc. the mobile phase of an organic solvent or organic solvent/water system is recommended.

Work Principle of Reversed Phase C4 HPLC Column
Reversed phase C4 HPLC column is the most widely used method for the separation of biomolecules, proteins, and enzymes. Reversed phase C4 HPLC column is a liquid chromatography separation mode with the surface nonpolar carrier as a stationary phase and solvent with stronger polarity than the stationary phase as the mobile phase. The stationary phase of reversed phase C4 HPLC column is mostly silica gel surface bonded hydrophobic group, which is separated based on the hydrophobic action of different components and hydrophobic groups in the sample.

Sample Retention of Reversed Phase C4 HPLC Column
The retention values of the samples in the reversed phase C4 HPLC column are mainly determined by the stationary surface area, bonding phase-type, and concentration. The retention values usually increase with the increase of chain length or the hydrophobicity of the bonding phase. The retention value of the sample can also be adjusted by changing the mobile phase composition or solvent strength depending on the nature of the organic solvent and its concentration in the mobile phase. In reversed phase C4 HPLC column, the low minimum retention value can be obtained with high solvent strength and low polarity mobile phase.

Usage of Reversed Phase HPLC Column
In the daily separation and analysis work, the correct use and maintenance of reversed phase high performance liquid chromatography column is very important, whether the column is used properly or not directly affects the life of the column, a little carelessness will reduce the column efficiency, shorten the service life or even damage. During the chromatographic operation, the following issues need to be noted to maintain the chromatographic column:
1. When handling and replacing the post, the action should be light and the joint should be screwed properly. Strong mechanical vibration must be prevented to avoid voids in the column bed.
2. If the instrument is used for routine analysis and the sample type is limited, but the number of analyses is high, it may be useful to have a special column for each type of routine analysis, which will help to extend the life of the column.
3. Generally speaking, a reversed-phase high performance liquid chromatography column cannot recoil, and only when the producer indicates that the column can recoil can the impurities left in the column be recoiled. Otherwise, the recoil will quickly reduce the column efficiency.

The Basic Operational Steps Of SPE Cartridges

SPE technology is a physical extraction process including liquid phase and solid phase based on the theory of liquid-solid chromatography, which uses selective adsorption, selective elution to enrich, separate and purify the sample. In daily application, SPE cartridge can also be regarded as a simple chromatographic process approximately. SPE often adopts the separation principle by liquid chromatography with selective adsorption and selective elution.

Working Procedures of SPE Cartridge
The specific working procedures are as followed: make the liquid sample solution pass through the adsorbent, retain the substance under test, then choose the appropriate strength solvent to flush the impurity, and then use a small amount of solvent to quickly elute the substance under test, so as to achieve the purpose of rapid separation, purification, and concentration. It is also possible to selectively adsorb and interfere with impurities and allow the substance under test flow out, or simultaneously adsorb the substance and impurities under test, and then use a suitable solvent to selectively elute the remaining substance under test.

The capacity of SPE Cartridge
The capacity of the SPE cartridge refers to the adsorption capacity of solid-phase extraction cartridge filler. The capacity of solid-phase extraction cartridges with silica gel as matrix is generally 1~5 mg/100mg, that is, the column capacity is 1%~5% of the filler mass. while the capacity of the bonded silica gel ion exchange adsorbent filler is expressed in meq/g, i.e., the capacity per gram of filler is X mg eq. Such filters typically have a capacity of 0.5~1.5 meq/g. Column capacity must be considered when selecting solid phase extraction columns because the sample matrix is usually more complex. Therefore, in considering that the column capacity should be the target compound plus the total amount of impurities that can be adsorbed cannot exceed the column capacity. Otherwise, some of the target compounds may not be adsorbed during the sample loading process, resulting in low recovery.

The Basic Operational Steps of SPE Cartridges
According to different retention mechanisms of fillers, the basic operational steps of SPE cartridges are slightly different.
1. The retention of filler is the target compound
The basic operation is normally divided into four steps: the first step is activation, which is for removing the impurities in the cartridge and creating a certain solvent environment. The second step is sample loading, which is using a certain solvent to dissolve the sample and moving them to the cartridge to retain the component on it. The third step is drip washing, which is for removing the disrupting chemicals to the maximum extent. The fourth step is elution, which is eluting the analyzed matter with a small volume of solvent and collect it.

2. The retention of filler is the impurity
There are basically three steps for the SPE operation: the first step is activation, which is for removing the impurities in the cartridge and creating a certain solvent environment. The second step is sample loading, which is moving the sample into the cartridge. At this time, most parts of the target compound will flow out with the sample base solution. The third step is elution, which is drip washing the component and merging the fluid.

The Basic Operational Steps Of SPE Cartridges

An explanation Of The Pipette

Classification
Divide fat belly pipette and commonly used pipette. It consists of a rubber nipple and a glass tube with a pointed mouth.

Use
Extract or add a small amount of reagent and extract supernatant to separate the precipitate.

Matters needing attention
During drip-adding, the pipette should be kept perpendicular to the top of the container, avoid tilting, do not stand on its head, do not reach into the container, do not touch the container wall. In addition to absorbing the solution, the piping tip should not touch other utensils to avoid contamination of impurities. Do not use one tube for two purposes.

The ordinary pipette needs to be cleaned after use, while the special pipette can not be cleaned, it needs to be dedicated to the tube, put back to the original reagent bottle after use. When using, do not use the only thumb and index finger pinch, with middle finger and ring finger clip.

Method of use
1. When using the eyedropper, squeeze the rubber nipple with your finger to expel the air from the eyedropper, then put the eyedropper into the reagent bottle, release your finger, the reagent will be inhaled.
2. The rubber head should be kept on the upper part of the dropper after taking the liquid, and should not be laid flat or inverted to prevent the reverse flow of the solution from corroding the rubber head.
3. Drop the liquid, it should be suspended on the top of the beaker, do not touch the burning glass wall, so as to avoid contamination of the dropper or reagent pollution.
4. Do not put the dropper on the test stand or anywhere else to avoid contamination.
5. Rinse the used dropper immediately with clean water for reuse.
6. Do not use the uncleaned dropper to absorb other reagents (do not rinse the dropper on the bottle with water).

About Some Question And Answer For QuEChERS

1. Why does the QuEChERS approach recommend use dry ice or liquid nitrogen homogenizing frozen samples and extracting samples while frozen?
The frozen samples were homogenized with dry ice or liquid nitrogen, and the samples were made into a fine powder (smaller particle size, more homogeneous), thus maximizing the extraction surface area and making the samples easier to process.
Samples should be extracted during freezing to prevent analyte degradation.

2. When I used the QuEChERS method to reconstruct the extract in LC/MS mobile phase solvent, precipitation would occur. How do I get over it?
If sediment is present during reconstruction, it can be ultrasonically treated and centrifuged to see if the sediment has entered the solution. If the recovery solvent is a percentage of methanol in water, first add methanol to dissolve the sample. Ultrasonic treatment and vortex before adding water.

3. Why wasn’t the original QuEChERS approach buffered?
The non-buffered was developed for the analysis of fewer pesticides. The buffered is introduced, to apply to larger pesticide screen, and many compounds show pH dependence.

4. In the extraction procedure of the QuEChERS method, what are the AOAC criteria for adding extractive salts and solvents?
For each gram homogeneous sample, it is recommended to add 1 ml 1% acetic acid to acetonitrile and 0.5 g anhydrous magnesium sulfate/sodium acetate (4/1, w/w) to acetonitrile as required by AOAC 2007.01.

5. In the dispersion d-SPE step of the QuEChERS method, what are the AOAC criteria for adding magnesium sulfate and SPE adsorbent?
For each 1 ml sample in the extraction step, a ratio of 3:1 magnesium sulfate/SPE adsorbent mixture of 200 mg is recommended. For example, it is recommended to use 1200 mg of magnesium sulfate and 400 mg of PSA when the 8 ml bisected sample in the extraction step is subjected to the dispersed SPE purification step.

6. In the QuEChERS method, how many (volume) of the initial extract and dSPE extract do I expect after centrifugation?
Depending on the moisture content of the sample, 15 g of the sample produces approximately 11-14 ml of the initial acetonitrile extract. During the SPE step, the salt and adsorbent dSPE blend lost almost half of the extract, with approximately 6 ml of the final extract extracted from the 15 g sample.

7. What modifications can you make to dry samples to improve the extraction procedure of the QuEChERS method?
For dry samples with less than 80% water content, you can start with half of the sample and then add cold water to bring the AOAC method to 15 g and EN method to 10 g.EN 15662 provides specific guidelines for adding water to different substrates. For example, it is recommended to add 10 ml of water to a 5 g grain sample.

8. Using the QuEChERS extraction kit, I accidentally sprinkled some salt while distributing it into the centrifuge tube. Will my results be affected?
QuEChERS extracted the excess salt in the procedure. Salt was first added to remove some of the water and cause the phase separation between acetonitrile and water. If the overflow (<1g) does not affect your results.

9. Is it necessary to dry and reconstruct the extract from the d-SPE step in the QuEChERS method for LC/MS analysis?
The chromatographic properties can be improved by evaporating the sample and pre-preparing it in the initial LC mobile solvent. Strongly recommended, but not required. If the analyte of interest is not eluted early in the chromatogram, you can leave without separating the sample or drying.

10. What is the approximate pH to be achieved using citrate as per EN 15662? What is the buffer range?
Most samples have a pH of between 5 and 5.5. Buffer range is approximately pH 2-7.4.

Certificate, Character And Extensive Application Of Filter Cartridge

Filter cartridge is a useful tool that contains filter media to capture and retain particles infiltration system. We can find filters cartridge not only in various lengths and diameters, but being made of different construction materials as well. As the flow is from outside to inside, the filters need a strong core to handle the increased pressure differential during filtration. For easy installation, the cartridges can be installed in pressure vessels with guide rods.
Certificate and Character of the Filter cartridge

1. Product filter membrane quality: There are two types of imports, domestically produced, which are convenient for quality sensitive customers and price-sensitive customers to choose;
2. The filter cartridge can be used in electronics, pharmaceutical, food, and other fields, as well as in the chemical and water purification fields. Therefore, the product has a wide range of applications and the quality can completely reach the standards of sterilization and impurity removal;

3. Filter cartridge Certificates: There are many test certificates for Filter cartridge, but they all belong to the factory’s certificate. The specific aspects are as follows:
FDA certification: It is an important quality certificate for the application in the US food field;
EN certification: It is an important quality certificate for the application of imported foods in the European Union; Ion migration: It is also a test report in terms of safety. It focuses on detecting whether toxic ions have migrated out during the use of the filter element, causing danger and harm.

Bacterial challenge experiment: This experiment is an important performance test report certification for sterilization filter, but it is a destructive experiment, that is, a filter is discarded after completing the test. Integrity test report: The integrity test report is mainly for the bubble point test, water intrusion test, and diffusion flow test of the filter element, some of the listed plant performance tests are performed. The result is an important part of the COA. Generally, each filter element will have an integrity test report sent with the goods.

Filter cartridge electronic production process
1. Class 100,000 clean workshop + high-purity water rinse 4H, in line with electronics production requirements; the inner and outer diversion layers are imported PP long-fiber non-woven fabrics;
2. The retention rate of the imported film 99%; domestic film 80-90%.

Filter cartridge pharmaceutical production process
1. Class 100,000 clean workshop + high-purity water rinse for 30 minutes, in line with GMP pharmaceutical standards; the inner and outer diversion layers are imported PP long-fiber non-woven fabrics;
2. The retention rate of the imported film 99%; domestic film 80-90%.

Food-grade production process
1. Class 100,000 clean workshop + high-purity water washing 4H, in line with FDA food safety regulations; inner diversion layer: imported PP filament nonwoven fabric; outer diversion layer: domestic non-woven fabric;
2. The retention rate of the imported film 99%; domestic film 80-90%.

Filter cartridge chemical-grade production process
1. Clean workshop + sterile air purging; retention rate 80-90%;
2. Inner diversion layer: imported PP long-fiber non-woven fabric; outer diversion layer: domestic non-woven fabric.

Water treatment grade production process
1. Clean workshop + sterile air purging; retention rate 80-90%;
2. The inner and outer diversion layers are made of domestic non-woven fabrics.

Ordinary production process
1. Clean workshop + sterile air purging; retention rate 60-70%;
2. The inner and outer diversion layers are made of domestic non-woven fabrics.

Certificate, Character And Extensive Application Of Filter Cartridge

What’s The Uniqueness Of Hawach Vacuum Filtration Device?

Components of Hawach vacuum filtration device
Multi-connected glass: glass filter cup, high borosilicate filter head, stainless steel filter holder 316L, stainless steel valve, aluminum alloy clip, dust cover, rubber plug.
Stainless steel multiple: stainless steel vacuum filtration: 316L cap, head, holder and valve, aluminum alloy clip, dust cover, rubber plug.
Solvent filter: Triangular effusion bottle (1L) sand core filter, filter cup (300ml), retaining clip, dust cover, hose, hose connector.

Features of vacuum pump
1. Advanced design, high working efficiency, and long service life.
2. No working medium is required (no oil pump), no pollution, and filter material is built in the gas exchange compartment of the device to ensure the purity of the air.
3. Ideal vacuum and high air velocity.
4. The motor used is provided by ODM, the professional motor manufacturer.
5. Equipped with a thermal cut-off protector, when the temperature of the pump reaches 130℃, the power will be cut off automatically to protect the motor from loss.
6. Adopt non-friction membrane body movement, no heat, no friction loss. The diaphragm adopts imported rubber, corrosion resistance and long service life.
7. It installs a cooling exhaust system that can be operated automatically to guarantee the 24-hour smooth operation.
The anti-corrosion pump (anti-corrosive type) is in surface contact with Teflon and has full chemical resistance.

Stainless steel multiple vacuum filtration devices
1. Can process multiple samples at the same time without contaminating each other and improve work efficiency.
2. Stainless steel filter is easy to be sterilized by high temperatures, and resistant to high temperature and corrosion damage.

Solvent filter
1. High-quality glass material, the glass is smooth and transparent, with no bubbles, with uniform wall thickness.
2. Using ultra-hard high-quality glass material, resistance to extreme temperature changes up to 280℃.
3. It has good pressure resistance and can be used for autoclaving.
4. Fast flow, excellent sealing, standard grinding.
5. Dimensions are in line with international standards and can be compatible with various brands.

What’s The Uniqueness Of Hawach Vacuum Filtration Device?

Prevention And Control Of COVID-19

Novel coronavirus pneumonia named COVID-19 by WHO, which is a serious communicable disease. Now it has been defined as a public health emergency of international concern and launched the first-level public health emergency response. It can be transmitted by human-to-human through droplet infection, contact transmission, and cross infection. The incidence rate, case fatality rate, and the recovery rate can be different according to prevention and control consciousness and action. To curb the spread of the virus, firmer resolve, doubled efforts and more decisive measures should be taken. Since the outbreak started, the Chinese government has taken the most comprehensive, thorough and rigorous prevention and control measures and waged a resolute fight against the epidemic. China has taken the strictest prevention and control measures to beat COVID-19 and protect the safety and health of the Chinese people and take it as the top priority of the Chinese government.

Control measure is operated in an orderly manner, at the very beginning of the outbreak, Chinese government and people have made all-out efforts to donate prevention materials to people who are in lack, release information in a timely manner, work closely with a health organization, intensify analysis and protection on epidemic development, improve measures for dealing with the risk of imported infections and strengthen exchanges and cooperation within different institutes. What’s more, under the strong leadership of the Chinese government, greater efforts have given to improve coordinating mechanisms of epidemic control strategies, enhance sharing of experience in prevention and treatment and advance joint scientific research. Community-based control of the contagion is efficient in the prevention and control of the COVID-19. The mechanisms of data sharing, information disclosure and inspection of people returned from Hubei province and Wuhan, as the priority regions in epidemic control, those provinces should remain consistent and cautions. Patients are provided with better medical treatment, and normal work and production in Wuhan will be gradually resumed.

Prevention And Control Of COVID-19

Different From The Flu, Is COVID-19 Much Worse?

Recently, more and more people ask the same question: is COVID-19 virus like the flu? The answer is NO. Compare to the seasonal flu, the Covid-19 is more contagious, more deadly, especially for old people. while the exact death rate is not clear yet.
most research shows that it might be higher than that of the seasonal flu.

The symptoms of typical include fever, cough, sore throat, muscle aches, headaches, runny or stuffy nose, fatigue. Sometimes, people will be vomiting and diarrhea too. Flu symptoms often appear suddenly, and most people will recover from it within two weeks. On COVID-19, known symptoms include fever, cough, and shortness of breath, and sometimes the patient just feels like he got the flu. But doctors are still trying to understand the full picture of its disease symptoms and severity.

Basic reproduction number or “R0”, which is an estimate of the average number of people who catch the virus from a single infected person, is widely used to determine how easily a virus spreads. The flu has an R0 value of about 1.3. Although the R0 for COVID-19 are still not determined by researchers, recent studies estimated an R0 value for COVID-19 might be 2-3, which means one infected person can spread the virus to about 2 to 3 person.

Also, it takes 14 days for people with Covid-19 infection to develop symptoms, with five days as the median. But for the flu, it only takes around two days. That means before people know they are sick, they might have more time to spread the virus symptomatically. That’s why we ask close contacts to be observed for 14 days.

COVID-19 virus leaped from animals to humans for the very first time, and none of us has any natural immunity to it. There is neither vaccine that can combat it right now, nor any approved therapeutics can slow its damage on a human.

Where did the COVID-19 virus come? How will it play out? Lots of uncertainties over the virus are threatening us very seriously. The most effective way to prevent and control the virus outbreak is early detection, early reporting, early diagnosis, early isolation, and early treatment. It’s in the first place that the confirmed cases to get an effective isolation treatment to decrease transmission.

Different From The Flu, Is COVID-19 Much Worse?

A Series Of Measures By The Chinese Central Government Concerning The COVID-19

March 16, 2020
Xi wrote back to urge all the post-90s members of the medical team of Peking University to let their youth blossom where the party and people need it most.
Premier Li Keqiang presided over the meeting of the central leading group on the response to the new pneumonia epidemic. The meeting laid out plans for further prevention and control of the epidemic and follow-up work to facilitate the full resumption of work and production and accelerate the restoration of economic and social order.

March 15, 2020
The joint prevention and control mechanism of the state council issued the work plan for the rescue and protection of children due to the lack of guardianship due to the impact of the new pneumonia epidemic.

March 14, 2020
Xi Jinping sent a message of condolences to Iranian President Hassan Rohani over the outbreak of pneumonia in Iran.
Xi Jinping sent a message of condolences to South Korean President Moon Jae-in over the outbreak of a new bout of pneumonia in the country.
Xi Jinping sent a message of condolences to Italian President Antonio mattarella over the outbreak of pneumonia in Italy.
Central steering group: medical treatment works in the first place in scientific and accurate efforts.

March 12, 2020
Xi Jinping spoke with UN secretary-general Antonio Guterres over the phone.
Premier Li Keqiang presided over the meeting of the central leading group on the response to the new pneumonia epidemic. The meeting called for accurate prevention and control and protection of the epidemic according to the changing situation of the epidemic.

Magic Gas-Liquid Separation Flash Column

First of all, the flash chromatography is a rapid separation mode of chromatography preparation. It applies the optimized preloaded medium and low-pressure columns for chromatographic separation. Since the flash chromatography is considered as medium and low-pressure chromatographic separation, its sharpness of separation is relatively lower than the High-Performance Liquid Chromatography.

Now, the flash chromatography technology is widely applied in research and development of drugs, sample purification, natural product refinement and other fields. On the whole, due to the advantages of low-cost, convenient and fast, the flash chromatography becomes one of the indispensable chromatographic separation tools for current High-Performance Liquid Chromatography preparation.

Types of HAWACH Flash Column
HAWACH flash columns fall into the following three series:
StarFlash series: silica gel flash column only, this series can be divided into standard and advanced sub-categories. Advanced silica has higher purity and better quality.
PureFlash series: silica gel construction and phase column. For example, C18(spherical inlet and irregular home-made), C4, C8, NH2, CN, HILIC, and oxide which are all imported fillers, corresponding to the high-end market.
DepuFlash series: silicone construction and phase columns, C18 (spherical and irregular),C8, NH2, CN, Phenyl, SAX, SCX, Diol are domestic fillers, corresponding to the low-end market.

In terms of the regular fillers of flash columns, the most frequently used filler is silica gel. Because in the early stages, the choice of filler for flash columns and thin-layer chromatography is limited. Also, some other bonded phases, such as C8 and C18 are too expensive. As a result, most of the application methods for flash columns are using silica gel as the separation matrix.

Flash column refers to saturated water with high pressure entering a relatively low-pressure container, and the saturated water becomes a part of the saturated water vapor and saturated water under the pressure of the container due to the sudden decrease in pressure.
In the chemical production process, the flash column can realize rough gas-liquid phase separation of materials. Before entering the atmospheric furnace, the flash column can be roughly separated, which can reduce the load of the atmospheric furnace.

How does the flash column work?
When water is heated at atmospheric pressure, 100 ° C is the highest temperature allowed for liquid water at that pressure. Reheating does not increase the temperature of the water, but only converts it into steam. The heat absorbed by water before it reaches the boiling point is called “sensible heat,” or saturated water sensible heat. “latent heat” is The heat required to convert saturated water into steam at the same atmospheric pressure.

However, if the water is heated under a certain pressure, the boiling point of water will be higher than 100 ° C, so more sensible heat is required. With the higher the pressure, the higher the boiling point of water and the higher the heat content. The pressure decreases and part of the sensible heat are released. This part of the excess heat will be absorbed in the form of latent heat, causing some water to be “flashed” into steam.

Magic Gas-Liquid Separation Flash Column

Comparison Between Glass And Plastic Sample Vial

Now, the sample vial has formed a considerable industrial scale, and has been concerned by the instrument industry and academia. At the same time, its application has covered many key industries and fields such as food safety, environmental monitoring, quality inspection, commodity inspection, disease control, scientific research and so on.

The goals when using a sample vial is to handle of the processed samples. The scientists transfer the samples into suitable sample vials with closure, or inject the sample directly into the sample vial for analysis. The scientists also transfer the sample solution into a suitable sample vessel and seal it to prevent from evaporation after sample processing. So the quality of the sample vials is important to keep in your mind.

As a widely known fact, not all glass is the same in the glass industry. And the quality of glass which is used for the construction of reagent lab-wares must be in the first place when you select sample vials. Type I Borosilicate Glass is appreciated as higher quality and more resistant to thermal shock than common Type III soda lime glass. The glass not only does excellent performances at high temperatures, its chemical resistance to acidic, neutral and alkali solutions is pretty good too.

The sample vials are essential for many lab. What kind of sample vial is suitable for you, the glass one or plastic one? Here is the answer.

Glass sample vial
Laboratory glass sample vials are classified by the USP (United States Pharmacopeia) based on their water resistance.
1.USP Type 1, Class A, 33 Borosilicate Hydrochloride Glass
It is the most chemically inert glass and is widely used in laboratories, especially for chromatographic analysis. Class I glass is mainly composed of silicon and oxygen, contains trace amounts of boron and sodium, has the lowest dissolution, and has a linear expansion coefficient of 33.
2.USP Type 1, Class B, 51 borosilicate hydrochloride glass
It is mainly composed of silicon and oxygen, contains trace amounts of boron, sodium, and alkali metals more than A-grade glass, but still meets laboratory use.
3.Silanized or deactivated glass
It is a borosilicate hydrochloride glass that has been deactivated by organosilanization of glass.
4.USP TYPE 11, 111 and NP
The soda-lime glass’s chemical resistance is not as good as borosilicate glass.

Plastic sample vials
1.Polypropylene-PP
It is a hard material that can be processed into many colors and has good chemical resistance, suitable for short-term storage of most laboratory chemicals. When aromatic or halogenated hydrocarbons are used, their resistance decreases over time. Due to its low iron content, it can be washed with enoic acid and deionized water.
2.Polymethylpentene-TPY
It is a hard, transparent material with a high melting point and a useful range of 0-170℃. Due to the high transparency, TPX sample vials can replace opaque PP. Its chemical resistance is similar to PP. TPX sample vials are usually used in the case of samples or high temperatures. TPX sample vials are brittle at room temperature.

Comparison Between Glass And Plastic Sample Vial

Instruction And Character Of Syringe Filter

1. The housing of the syringe filter is made of polycarbonate, polypropylene, and polyethylene plastic. The upper and lower parts are welded by ultrasonic waves, which is resistant to high pressure. There is no leakage of the product.

2. Syringe filters are widely used in laboratories. It does not require membrane replacement and filter cleaning, and saves complicated and time-consuming preparation work. It is mainly used for sample pre-filtration, clarification and removal of particles, liquids and gases.

Classification of disposable syringe filter

1. Classification of liquid properties: water phase filtration; organic phase filtration.
2. Filtration purpose or process classification: sterilization filtration; clarification filtration; pre-filtration; particle removal filtration.
3. Interface form: female bayonet formula socket.
4. Dimensions: 4mm, 13mm, 17mm, 25mm, 30mm, 33mm, 50mm etc.
5. Filter layer structure: single-layer membrane structure; multi-layer membrane structure; capillary structure.
6. Hydrophobic polytetrafluoroethylene membrane (PTFE): used for filtering air, gas and hydrophobic chemicals.

Character of syringe filter

1. The PTFE membrane of the syringe filter is completely made of natural and permanent hydrophobic PTFE material. Even under a very low pressure difference, it can ensure that moist air or other gases can pass without hindrance, while the aqueous solution cannot pass through. PTFE membrane has extremely strong chemical compatibility, and is capable of filtering almost all organic solvents and highly corrosive chemicals. When the PTFE membrane must be used to filter the aqueous solution, it must be pre-soaked with ethanol or isopropanol before the aqueous solution can be filtered.
2. Syringe filter glass fiber pre-filtration membrane (GF): used to improve the filtration rate and continuous filtration; glass fiber filter membrane is a deep layer filtration, its main purpose is to be used as a pre-filtration layer directly on the filter membrane.
3. Syringe filter nylon membrane (Polyamide, Nylon): used for filtering alkaline solution and organic solvent.
For organic solvent filtration, such as HPLC mobile phase particle removal, nylon membranes are more economical and practical than PTFE membranes. Due to the relatively high adsorption performance of nylon membranes, it is generally not recommended for filtration of culture media or biological samples such as protein solution, so as to avoid loss of samples due to adsorption. In this case, a low-adsorption cellulose acetate membrane (CA) is generally more suitable.

Instruction And Character Of Syringe Filter

The Advantages Of Using A Filter Membrane To Treat Drinking Water

(1) No coagulant required

From the past experience of using filter membranes, the raw water used for drinking water (river water, reservoir water, and eutrophic lake water) is treated with MF membrane without coagulant, and the conventional methods of coagulation, precipitation, and filtration with coagulant Compared with the treatment, the water quality of the former and the water treated by the latter is equal to or more than that of the treated water.

(2) Simple automation and easy unmanned management

Membrane separation technology only provides the necessary operating pressure for the supply of raw water, and it only needs to run for a long time to flush the filter membrane, and there is no other process. At present, there are many steps in the process of coagulation, sedimentation, and filtration of purified water, and the dosage rate cannot be set in terms of administration. In this case, it is easy to automate the membrane device and make it unmanned, but it is not easy to automate conventional processing.

(3) The filtration membrane water plant occupies less land

Adopting filter membrane water plant, the membrane device covers a small area, and it is easy to reduce the plant area occupied by conventional treatment with the same water production volume by half. The remaining places can be equipped with activated carbon treatment devices. As the filter membrane water plant can be unmanned, the buildings and supporting facilities where employees live can be reduced.

The function of Membrane Filter
The filter membrane as the original filter is characterized by a very thin filter layer, so its filtration mechanism is mainly screen removal, and the adsorption effect is very small. However, if the water contains oil, it is easy to block and not easy to backwash.

Application of filter membrane

In addition to being used for water treatment, filtration membranes can also be used in the manufacture of ultrapure water and desalination. Generally, reverse osmosis membranes (nanofiltration membranes) are used. In addition, it is used for feces and urine treatment, urban sewage treatment, and various wastewater treatment. Ultrafiltration membranes and microfiltration membranes are generally used. Industrially, it can be used in dairy product manufacturing, semiconductor manufacturing, food manufacturing, paper manufacturing, and pharmaceutical manufacturing. Ultrafiltration and microfiltration membranes are also commonly used.

Filter membranes are used in food and beverage, medical and pharmaceutical, municipal water treatment, industrial high-purity water, boiler make-up water, seawater desalination, ultra-pure water in the electronics industry, wastewater treatment and reuse, material concentration purification and other industries.

More extensive, household ultrafiltration water purifiers, ultrafiltration membranes. It can remove large molecules, colloids, proteins, particles, etc. in the solution, and has the characteristics of low use pressure, large water production, and easy operation.

Hawach could supply various filter membranes for different areas. If you want to buy the filter membrane. Please contact us.

Solutions For High Pressure And Baseline Drift In HPLC Columns

This is the most common problem in the use of high performance liquid phase, which refers to the sudden rise of pressure, generally due to the blockage in the flow path. At this time, we should check by sections.

Disconnect the inlet of the vacuum pump.
At this time, the peek tube is filled with liquid, so that the peek tube is lower than the solvent bottle, to see whether the liquid drops freely. If the liquid does not drop or drops slowly, the solvent filter head is blocked. Treatment method: soak in 30% nitric acid for half an hour, then rinse with ultra pure water. If the liquid drips freely and the solvent filter head is normal, check again;

Open the purge valve
If the pressure does not drop obviously, it will be blocked by filter white head. Treatment method: take out the filtered white head and use 10% isopropanol for ultrasonic for half an hour. If the pressure drops below 100psi (6.7bar), the filter white head is normal, and recheck;

Remove the column outlet end
If the pressure does not drop, the HPLC column is blocked. Treatment: if the buffer salt is blocked, flush 95% water to normal pressure. If some strongly retained substances cause blockage, the mobile phase stronger than the current one should be used to rush to normal pressure. If the washing pressure does not drop for a long time according to the above method, the inlet and outlet of the column can be connected to the instrument in turn, and the column can be washed with mobile phase. At this time, if the column pressure still does not drop, only change the column inlet sieve plate, but once the operation is not very good, it is easy to cause column efficiency drop, so try to useless.

Solutions For High Pressure And Baseline Drift In HPLC Columns

An Introduction Of SPE And Method For Selecting SPE Cartridge

Method for selecting SPE cartridge
The capacity of the SPE cartridge refers to the adsorption amount of the column packing. For silica-based solid-phase extraction columns, the capacity is generally 1 to 5 mg/100 mg, which means that the column capacity is 1% to 5% of the mass of the packing. The capacity of the bonded silica gel ion exchange adsorbent packing is expressed in meq/g, that is, the capacity per gram of filler is X milligram equivalent. The capacity of this kind of packing is usually 0.5 ~ 1.5 meq / g.

There are many types of SPE cartridges. It is necessary to reasonably select SPE cartridges with suitable packing and reasonable specifications according to the analysis object, detection method, and laboratory conditions. The extraction capacity of the SPE column for the analysis object, the volume of the sample solution, the final volume of the eluted solution, and the total amount of the analyte and interference in the sample solution should be considered. Generally, the total mass of the test object and the interfering substance adsorbed by the adsorbent in the column should not exceed 5% of the total mass of the adsorbent. The volume of the eluent should generally be 2-5 times the volume of the bed of the extraction column.

How to choose an SPE cartridge?

SPE cartridge is a sample pretreatment device developed from chromatography column for extraction, separation, and concentration. Most common SPE cartridges are injection syringe-type devices made of polyethylene. There are two plugs made of polypropylene or glass fiber in the device. The two plugs are filled with a certain amount of chromatographic adsorbent (packing). The SPE cartridge is packed with a high-purity spherical adsorbent, which is more uniformly distributed, ensuring the repeatability and consistency of the experimental results, in order to ensure a safe, reliable and sample preparation process.

In addition to the required specifications, the key to selecting an SPE cartridge is its packing. When selecting an extraction column, you must choose the appropriate packing according to the type of sample to be tested and its physical and chemical properties. Solid-phase extraction packings are usually chromatographic sorbents and can be roughly divided into three categories, which are based on silica gel, polymers, and inorganic materials.

The first type is based on silica gel, such as C18 solid-phase extraction cartridges. Silica gel is very polar and weakly acidic. It can be used in two phases: normal-phase or reversed-phase. The polarity is weaker than silica gel, and the non-polarity is weaker than C18 or C8 during reversed-phase extraction. It has a good extraction effect for steroids. It is usually used for the extraction of non-polar or weakly polar compounds or the removal of polar impurities, which is mainly used for blood and urine samples and their metabolites, peptide desalination, enrichment of trace organic compounds in environmental samples, organic acids in beverages.

The second type is based on polymers, such as polystyrene-divinylbenzene. Styrene-divinylbenzene polymer featuring high-purity and crosslinking can withstand extreme pH conditions and different solvents, with excellent properties for polar compounds retention ability It can be used as a general-purpose adsorbent for acidic, neutral and basic compounds. It is usually used to retain hydrophobic compounds containing hydrophilic groups under reversed-phase conditions such as phenols, nitroaromatics, nitramines, nitrates Class, etc.

The third type is based on inorganic materials, such as Flori diatomite, alumina, and graphitized carbon. Florisilite is a kind of polar silica gel adsorbent compounded with magnesia. The extraction column based on it is suitable for adsorbing polar compounds such as polychlorinated biphenyls, polycyclic aromatic hydrocarbons, organic compounds from non-polar substrates. Chlorine residues, etc.; graphitized carbon black (CARB) extraction columns, with graphitized carbon black as a packing, has a very fast extraction process. The adsorption capacity of the compound is more than double that of silica gel. Due to the regular six-membered ring structure on the surface of graphitized carbon black, it has a strong affinity for planar molecules, which is very suitable for the extraction and purification of many organic substances, especially for separation or re-movement of various substrates such as pigments, sterols, phenols in fruits and vegetables; alumina-based fillers have three types of acid, alkali and neutral, which are suitable for the separation and extraction of acid, alkaline and neutral solvents.

An Introduction Of SPE And Method For Selecting SPE Cartridge

To List The Features Of HAWACH Manual Pipette And Electronic Pipette

As a common tool used in labs, pipettes can transport measured volumes of liquid. You can find mechanical pipettes and electronic control pipettes in the market.

The HAWACH manual pipette features smooth piston movement and light weight for operational comfort and accuracy, and a wide range of adjustable capacities, making it suitable for a wide range of applications and with the best cost performance. Moreover, its outstanding support and service does not stop after delivery and customers always have free and unlimited access to their support team.

Three series of manual pipette
HAWACH manual pipette is home to three series, standard, advanced and advanced plus. The first two are semi-autoclave and last one is full-autoclave, which is more suitable for biology. Also, they can be divided into single channel adjustable volume pipettes, single channel fixed volume pipettes, 8 channel adjustable volume pipettes, and 12 channel adjustable volume pipettes. Moreover, all the tip head are made of PVDF.

Outstanding features
-Under ergonomic design;
-Extremely lightweight pipetting and excellent tip ejection performance;
-Easy to calibrate and maintain, fewer parts, easy to disassemble;
-Range lock with lock design;
-Clear figures show at a glance;
-Highly flexible tip connection cone ensures sealing and good chemical resistance;
-A wide range of tip suitability.

About QuEChERS Introduction And The HAWACH QuEChERS Products

HAWACH QuEChERS products
HAWACH is a fresh and enthusiastic company. A team of experts works with joy & responsibility, intensely caring for your orders to be processed quickly and successfully. It’s precision in manufacturing premium QuEChERS kits, SPE columns, pipette, syringe filter, etc. plus our flexibility and unique commitment to tackling any task, enables us to provide the right products that not only meet the standards but also your individual expectations – to the right time.

HAWACH has independently developed the QuEChERS series. This series of products covers AOAC 2007.01 and EN 15662 method series set of two major types of extraction kits and purification kits, which are easy pourable and mess-free handling. If you use different salts or mixtures, we customize the kit according to your needs in a reservoir that fits the best for you.

QuEChERS is mostly used for pesticide residue detection in food. The detection of pesticide residues in food is an important issue related to food safety, and pretreatment is the longest and most time-consuming part of pesticide residue detection. The quality of the pretreatment determines the accuracy and precision of the analysis. degree.

The QuEChERS method has a high recovery rate, the recovery rate of a large number of polar and volatile pesticide varieties is greater than 85%. High accuracy and accuracy of QuEChERS method can be corrected by the internal standard method; A wide range of pesticides that can be analyzed, including polar and non-polar pesticides, can use this technology to get better recovery rate. QuEChERS fast analysis speed can complete the processing of 6 samples within 30min. Low solvent usage, low pollution, low cost and no use of chloride-containing solvents. The QuEChERS method is easy operation, which can be done well without good training and high skills. Acetonitrile is sealed immediately after adding to the container so that The chance of contact with the staff is reduced. Few glassware is used in the sample preparation process, and the device is simple.

HAWACH QuEChERS product advantages
• The product is accurately weighed in advance, and the water-free ultra-clean packaging improves the quality of the results;
• The inorganic salts and adsorbents used as raw materials are all certified to be the highest-level reagents of the same brand at present, avoiding the introduction of interfering substances;
• The core products are packed in light-proof and sealed materials, which will not deteriorate due to storage and transportation;
• Long-term commitment to research and development of sample separation and purification, strong technical force.

About QuEChERS Introduction And The HAWACH QuEChERS Products

To Have A Full Knowledge Of Flash Column-Definition, Development And Advantages

In the narrow sense, FLASH refers to the preparation of a liquid chromatography system using a low-pressure short column that generates pressure with compressed gas and accelerates the elution rate of the mobile phase. In the broad sense, FLASH refers to all low-pressure liquid chromatography systems for infusion.

Development of flash column
After more than 20 years of development, FLASH chromatography has been widely used as a conventional purification and separation equipment. FLASH chromatography was born out of open glass column chromatography and is mainly used for the separation and purification of natural products and organic synthetic products.

Classical FLASH chromatography consists of a glass column, a liquid storage bottle, and a compressed air regulating valve. This type is low cost and easy to observe, but has low pressure and is easy to break. After improvement, a classic FLASH chromatography system was formed. It consists of an infusion pressure tank, a flow regulating valve, a flash preloading column, and a sample loading device. The equipment is compact, high pressure, easy to use, and highly reproducible. Classic FLASH chromatography still uses air pressure, with a pressure range of about 0-7 bar, a column length of about 15 cm, and a particle size of 40-60. Load solids and liquids and collect fractions manually.

Recently, due to the intensification of scientific research competition and the increase of labor costs in laboratories, a higher degree of automation and separation speed is required, and automated FLASH chromatography has been generated. The instrument also has a gradient elution system, a column switching system, and an automatic sampling system. The conditions can be selected and optimized to achieve unmanned operation, which greatly reduces labor costs and speeds up development.

To Have A Full Knowledge Of Flash Column-Definition, Development And Advantages

How Do I Set Up Vacuum Filtration And How Does It Work?

The vacuum filtration collects pollutants (mainly dust) sucked from the atmosphere to prevent system pollution, and is used between the suction cup and the vacuum generator (or vacuum valve).

It is mainly suitable for vacuum filtration in the production process of chemical medicine, petroleum and other industries. It can ensure that trapped particles are evenly distributed on the surface of the filter membrane, so it is particularly suitable for particulate matter Collection and counting. The other type uses a PTFE-coated stainless steel screen as a filter support pad, which is suitable for collecting filtrate, such as removing particles from samples. This type of filter is also recommended when filtering thicker liquids, such as when collecting particles from oil samples.

Known as a technique that the scientists used to separate a solid from liquid, sometimes the filtration can be deal with gravity which is very simple. But more and more people choose vacuum filtration, because it is faster and more efficient.

When you set up a vacuum filtration kit,first you should make sure to clamp your filter flask securely, as the flasks are easily upended. Also you should use the trap between your filter flask and the aspirator, and the thick-walled vacuum tubing, not the thin one.

After your setup is done, you can put a piece of filter paper on the filter and make it wet with the solvent you are going to pour through the filter.

You will find that a mixture of a solid and a liquid separated when you pour it through the filter. You can move the remained solid which stays in the flask with the aid of a spatula and wash it with a small amount of the solvent with low solubility.