How To Choose The Right SPE Cartridge To Meet Your Experiment Requirements?

About the advantages of Solid-Phase Extraction
Sample matrices vary widely, like vegetables, fruits, meat, eggs, milk, water, soil, rubber, textiles, etc., whether they are food or environmental samples, the complexity is also different. Simple samples can use the pre-processing method, but for complex samples, special pre-processing is required, such as using Solid-Phase Extraction (SPE for short) cartridges for further purification, separation of target substances and impurities, and further use in chromatography instruments. When you get a beautiful chromatogram, you will find that some pretreatment of the sample matrix will definitely use the SPE method.

As a sample pretreatment technology, SPE developed in recent years. It is a combination of liquid-solid extraction and column liquid chromatography technology, which is mainly used for the separation, purification, and concentration of samples. Compared with the traditional liquid-liquid extraction method, the recovery of the analyte can be improved, the analyte can be separated from the interference components more effectively, and the sample pretreatment process can be reduced. The operation is simple, time-saving, and labor-saving, which is widely used in medicine, food, environmental protection, commodity inspection, pesticide residue, and other fields.

Solid phase extraction instruments have unparalleled advantages: no special equipment and materials required; easy operation, no special equipment required; a good way to collect and enrich samples and improve detection sensitivity; faster than liquid-liquid extraction, saving solvent; automatic batch processing and good reproducibility.

About the choice of SPE cartridge
The choice of SPE cartridge packing and capacity is important.

SPE cartridge packing
First, select the appropriate packing based on the difference between the target compound and the interference, such as polarity, molecular weight, PKA value, etc. For reversed-phase, normal-phase, and adsorption solid-phase extraction columns, the mass of the extracted sample should not exceed 5% of the SPE column packing (the selectivity of the same adsorbent for different targets is different. This value is for reference only.); Ion-exchange solid-phase extraction columns must consider the capacity of ion exchange.

SPE cartridge capacity
In addition to the cartridge packing, the cartridge capacity should be considered, which needs to ensure the packing has sufficient capacity to retain 100% of the target compound. On the other hand, the packing is better not to be too much. The more packing, the greater the amount of solvent that will effectively elute the target compound.

Therefore, the SPE cartridge capacity must be considered when selecting the specifications of the SPE cartridge. Its capacity refers to the mass of a unit mass of packing that retains the compound with the main force. The capacity of the bonded silica gel column is generally 1% to 5%. Taking a 100 mg packed SPE cartridge as an example, its larger capacity generally does not exceed 5 mg. For the ion exchanger, the cartridge capacity is about 0.5 to 1.5 meq/g.

It is worth pointing out that, since we are mostly dealing with mixtures, in addition to the target compounds, there are many interfering substances. Therefore, when selecting the column specifications, the total amount of the target compound and the interferences that may be adsorbed under the extraction conditions must be considered instead of the target compound alone.

Otherwise, even if the target compound does not exceed the column capacity, the SPE column will retain some of the interfering compounds while retaining the target compound. Since the total of the two has exceeded the column capacity, as a result, some target compounds cannot be retained SPE column. Therefore, to be on the safe side, it is recommended that the column capacity be better than twice the estimated target compound content. Welcome to contact the Hawach team to learn more professional suggestions.

How To Choose The Right SPE Cartridge To Meet Your Experiment Requirements?

Application Of Filter Membrane In Food And Medicine

Hawach membrane filter is the use of pressure as the driving force to rely on the selectivity of the membrane to separate the components in the liquid.

In food membrane filter, there are two filtration methods:

1. Standard membrane filter technology for filterable liquids.
2. HGMF (hydrophobic grid filter membrane) technology for gas.

When performing food membrane filter, the operations used are:

1. Collect and dilute the sample, and then select the appropriate medium and drop it into a Petri dish with a sterile absorbent pad to completely wet the absorbent pad.
2. Flame sterilize the forceps, then remove the filter membrane from the sterile packaging and place it in the filter funnel.
3. Flame sterilize the mouth of the sample container, then pour the sample into the filter funnel, and then open the vacuum filter device to allow the sample to completely filter the filter membrane by vacuuming.
4. Rinse the filter funnel with sterile buffer, and turn on the vacuum filter again to allow the liquid to completely filter the filter membrane by vacuuming.
5. Flame sterilize the tweezers and remove the filter membrane from the filter funnel.
6. Place the filter in the prepared petri dish and incubate at a specific temperature for a period of time. Then, count and confirm the colony, and issue a test report.

In terms of medicines, membrane filter is mainly used for sterility inspection. The method of inspection is to verify that the test product has antibacterial and antifungal properties for the membrane filter method. It is the same as the actual sterility inspection. Each filter in the same model Filter the specified amount of test products (the number of containers and the filtration volume per container) in the filter or filter cartridge, rinse the filter membrane with the eluent at least 3 times, the volume of each eluent is 100ml, and the next eluent In the test, enter the bacteria used for verification (inoculation volume is 10-100CFU); take another filter or filter cartridge without filtering the test sample, and repeat the above rinse operation as a positive control.

According to the specific situation, the entire filter or half of the filter can be transferred to 100ml of the designated verification medium, or the medium can be added to the filter cartridge equipped with the filter. Verify the strains listed in the table and the corresponding media one by one, and put the container at an appropriate temperature for cultivation, the cultivation time does not exceed 14d.

If you use a new filter or filter (including different manufacturers or batch numbers, models), you need to do according to the requirements of the above membrane filter method, group test, that is, sample test group, peptone control group and positive control group to re-verify and confirm.

Membrane filter method is not only used in the fields of food and medicine, but also in many fields such as chemical industry, electronics, energy, environmental protection, and inspection. It is very extensive. It is a branch of modern separation technology. The use of membrane filters can have purification, separation and concentration, and other technological purposes.

Application Of Filter Membrane In Food And Medicine

Decisive Factors In Selection Of Filter Paper

Selection of Filter Paper
Choosing the appropriate filter paper should consider the following four factors: hardness、filtration efficiency、capacity and applicability.
1. Hardness: the filter paper usually becomes wet when it is filtered, and some experimental steps of filtration should consider using tough filter paper after wetting.
2. Filtration efficiency: the size and degree of the seepage holes on the filter paper will greatly affect its filtration efficiency. High-efficiency filter paper is both fast filter speed and high resolution.
3. Capacity: the solid particles accumulated during filtration can block the holes in the filter paper, so the more dense the seepage holes are, the higher the capacity is and the more sample can be filtered.
4. Applicability: different filter paper has different properties, some filter paper is done with special production steps, and some filter paper can be used to determine the nitrogen content in the blood. Note that the filter paper cannot filter zinc chloride, otherwise the filter paper will be corroded by zinc chloride and the performance effect will be reduced.
5. Specification: the qualitative filter paper grade BIO-1 is of 0.3 wet bursts, 88 basis weight, 180 thickness, and 11μm particle retention.

Production Process of Filter Paper
Hawach filter paper can be used to remove harmful dust, smoke, poison from the gas, can separate impurity particles from the liquid, and can block bacteria, microorganisms, and so on. The filter paper is made from one or various kinds of inorganic fiber, plant fiber, and synthetic fiber, by adding the appropriate amount of chemical auxiliaries and fillers and using paper copying technology, it has good filtration performance and crisp porous filter medium. In addition to the selection of raw materials, the proportion of filter paper also plays an important link in the production of filter paper.

Impact Factors in Performance
When filtering, in order to ensure that the filtration speed is fast, and to avoid the liquid flowing down the gap between the funnel and the filter paper, the filter paper should be close to the inner wall of the funnel and do not keep bubbles in the middle. If the filter paper edge is higher than the funnel edge, the liquid oil in the filter may overflow; if the liquid level in the funnel is higher than the filter paper edge, the liquid will also flow down the gap between the funnel and the filter paper, the filter paper should be close to the inner wall of the funnel, and no bubbles should be left in the middle.

Different Properties of Filter paper
Filter paper is an effective filter medium, and filter paper has been widely used in various fields. According to the different types of fibers that make up the filter paper, the properties and uses of the filter paper are also different. There are ordinary filter paper for general occasions, glass fiber filter paper for high temperature, and super clean polypropylene filter paper, and so on. Most of the filter paper is made of cotton fiber and is made in different ways for different applications. Because it is made of fiber, there are numerous small holes on its surface for liquid particles to pass through, while larger solid particles cannot. This property allows the separation of liquid and solid substances mixed together. While ordinary paper can only absorb 23% moisture, and cannot achieve the effect of filtration.

Decisive Factors In Selection Of Filter Paper

Description And Advantage Of Syringe Filter

Hawach syringe filter has the advantages of beautiful appearance, simple and reasonable structure, and surface polishing. It has the characteristics of low cost, small volume, large filtering area, fast filtering speed, low blocking rate, acid and alkali corrosion resistance, and long service life. Internally participate in different precision filter elements (such as PP filter cores, wire wound cores, folded filter cores, ceramic filter cores and other different types of filter cores) to remove various fine particles, colloids, metals, bacteria, residual chlorine and other impurities in water or air.

Food, beverage, medical chemical, pure (ultra-pure) water system, bottled water, mineral water production line, electronics and other professional water clarification, concentration and purification and air purification.

Fine filter (also called security filter), the barrel body is made of high-quality stainless copper, and the filter element machine is quick-opening. It does not need to use things to replace the filter element, which is convenient and fast. According to different water requirements, melt-blown PP filter core, wire wound cotton filter core, folded filter core and other combinations can be selected.

High filtration accuracy, uniform filter pore size; small filtration resistance, large flux, strong dirt interception ability, long service life; high cleanliness of the filter material, no pollution to the filter medium: acid and alkali resistant chemical solvents: high strength, high temperature resistance, The filter element is not easy to deform: the price is low, the running cost is low, it is easy to clean, and the filter element can be replaced.

The so-called chemical filters can selectively block, absorb, and eliminate harmful pollutants, unlike the simple air filtration equipment that mechanically removes impurities in the air. In daily life, this device can be said to be one of the common devices! Next, we will make an analysis one by one on the principle and performance of the equipment: the chemical filter is made of activated carbon material, the material has fine holes that are invisible to the naked eye, and most of the micropores are very small.

After testing, the equipment's filtration and dust removal methods are special. The adsorption function is mainly divided into two types, namely physical adsorption and chemical adsorption; most of the chemical filters used are hydrophilic materials, so the ability to adsorb water vapor is also very limited; The filter material used during this period is non-toxic and harmless, so it is used in the field.

The equipment can not only absorb the microorganisms in the air, but also effectively kill it; play a very good catalytic effect, so that some gas pollutants can be degraded or changed into non-toxic and harmless substances. Summarizing the above analysis, we can see that the filtration principle of chemical filtration equipment is very simple, but the effect of this equipment is not simple. If we only need to grasp it well, it can make the equipment play a good effect in practical operation.

The syringefilter is widely used in the laboratory. It does not require membrane replacement and cleaning of the filter. It saves complicated and time-consuming preparation work. It is mainly used in sample pre-filtration, clarification and particle removal, and liquid and gas sterilization filtration.

Syringe filter are widely used in laboratories and are designed to provide fast and efficient filtration solutions for water and organic solutions. These devices are made of various membrane filters containing polypropylene shells, and a special injection molding process improves burst pressure and filtration speed.

These syringe filters are suitable for many applications and can be used in pharmaceutical, environmental protection, biotechnology, food/beverage, and agricultural product testing laboratories. This disposable syringefilter is more convenient to use. If it is a water-based sample, use cellulose or polyethersulfone directly. If it is an acid or alkaline sample, use PTFE. If If it is organic, use nylon or regenerated cellulose. Don't look at the different styles and colors of each brand, but don't pay attention to these. The most important thing is the filter membrane inside. The quality of the filter membrane directly affects the filtration result.

Description And Advantage Of Syringe Filter

Application In Veterinary Drug Residue Detection

After research, it has been found that the QuEChERS method has more prominent characteristics and can be applied in a variety of applications, including not only fruits and vegetables, but also milk, blood, and meat. In order to obtain more satisfactory test results, the researchers improved and innovated the QuEChERS method on the existing basis, so that the QuEChERS method can be applied to the detection of meat food, and the pesticide residue on the meat food can be detected. If you want to purify meat food, you must remove its fat.

Therefore, relevant personnel should use a reasonable and scientific method to remove fat. In most cases, purifiers and extractants are used to purify meat food, so that the purity of the meat obtained and the accuracy of the test results are higher. This method has the advantages of simplicity, ease of operation, and low cost, so experts must actively use this method to create a safe and healthy food market for people, and apply this method to the detection of more high-fat foods, such as milk, various cooked foods, etc., which can accurately measure and analyze the pesticide residues of these foods to ensure food safety, and also promote the development of the agricultural market economy.

Li Feng and others used the QuEChERS method combined with liquid phase tandem mass spectrometry to detect 12 kinds of sulfonamides, 19 kinds of quinolones, and 8 kinds of benzimidazole drugs and metabolites in chicken liver. Finally, good effects of protein denaturation precipitation centrifugation, matrix water removal, fat and carbohydrate removal, and degreasing are achieved. Wang Zhi et al. improved the QuEChERS method, using 0.5% acetic acid acetonitrile as the extraction solution, PRIME HLB solid phase extraction purification, nitrogen blowing concentration, and reconstitution. Combined with UPLC-MS / MS high-throughput rapid detection of 8 kinds of hormones, 6 kinds of β-receptor agonists, and 4 kinds of antibiotic growth-promoting drugs in bovine liver. The results showed that the recovery rate was satisfactory and the relative deviation was small.

Conclusion
The QuEChERS method has the advantages of convenience, economy, and high accuracy of the test results, so it is widely welcomed in food testing. The traditional food safety detection method has low technical content, insufficient accuracy of the detection results, and limited detection range. The QuEChERS method has a wide range of applications and can detect food, agricultural, and veterinary drug residues in a timely, efficient, and accurate manner.

With the continuous improvement of scientific and technological levels and the efficient research and development of new extractants and catalysts, the QuEChERS method will greatly play a role in the detection of food, agricultural and veterinary drug residues.

Application In Veterinary Drug Residue Detection

Jacketed Glass Reactor-Volume: 1L-5L

Hawach is a reliable glass reactor manufacturer who can provide you with glass reactors of all sizes, designs for your unique requirement.
With our professional technician and experienced glassblower, we can develop ideal products according to your precise requirements.
The size of jacketed glass reactors can vary from 1L to 300L according to your different requirements.

Hawach table size jacketed glass reactor can be used to react, stir, mix, evaporate and concentrate in many laboratory experiments.

Instead of kettle rotating to stir up materials in rotary evaporators, paddle stirring in pyrex reactors is bigger, safer, faster, with more temperature options and discharge convenience. The reacting environment for jacketed glass reactors is well-sealed, which keeps the purity of materials as well.

All glass reactors can meet your general requirement of reacting materials in a vacuumed heating/cooling environment(with temperature and vacuum degree adjustable) made up with High Borosilicate Glass kettle, in which the materials can be mixed and reacting thoroughly by the stirring paddle and evaporate quickly into the condenser, becoming liquid collected into the receiving flask. Reacted materials left can be discharged through the bottom discharge valve(filtration bottom is also available).

Well-sealed all glass reactors of the mechanical sealing system with a durable PTFE valve keeps the glass reactor well sealed with high vacuum.

Double-layered glass reactors with a tick mark on the inner kettle have a precise temperature that can not be affected by the jacketed glass layer. The integral upright design saves space and easy to assemble. Steel retaining plate or lockable casters made by PU makes the moving more smooth and steady.

Stainless PTFE coating paddle on jacketed glass reactor is strong enough to stir dense materials in pyrex reactors.
Constant voltage funnel ensures constant feeding of materials for constant reaction.

PTFE valve in the bottom and the unique no dead angle design inside jacketed glass makes the discharge clearly and thoroughly.

All glass reactor made of transparent high borosilicate glass makes the whole reacting process visible, providing a reference for any adjustment.
With it’s a small size, the table sized all glass reactors are easy to assemble and disassemble, clean and transport, having faster stirring speed to accelerate the reacting process, which is ideal for pre-production adjustment and small scale experiment.

As a professional glass reactor manufacturer, Hawach offer update options as follows:

* Stainless steel or an aluminum alloy made coupling for dense materials;
* Bottom filter for filtration of liquid and solid;
* Explosive motor for Flammable, explosive and volatile containing materials.
* PTFE coating is available for a corrosive environment.
* Continuous collection device.
* Lifting and rotary function available.
* Flux and continuous reacting devices.
* Other customized update options for jacketed glass reactors to be continued…

Jacketed Glass Reactor-Volume: 1L-5L

Brief Analysis Of The Process Of Molecular Distillation To Achieve Material Separation

During molecular distillation, the bulk mixture flows along with the heating plate and is heated, and light and heavy molecules will escape from the liquid surface and enter the gas phase because the free paths of light and heavy molecules are different. Therefore, the movement distance of molecules of different substances after escaping from the liquid surface is different. If a condensing plate can be set properly, light molecules reach the condensing plate and are condensed and discharged, while heavy molecules cannot reach the condensing plate and are discharged along with the mixed liquid. This can achieve the purpose of material separation.

Molecular distillation can be divided into the following four processes:
1. Molecules diffuse from the main body of the liquid phase to the evaporation surface. Generally, the diffusion rate in the liquid phase is the main factor that controls the rate of molecular distillation.
2. Free evaporation of molecules on the surface of the liquid layer. The evaporation rate increases with increasing temperature, but the separation factor sometimes decreases with increasing temperature. Therefore, the economical and reasonable distillation temperature should be selected on the premise of the thermal stability of the processed material.
3. The molecules flying from the evaporation surface to the condensation surface may cause each other to collide with each other, or may collide with air molecules remaining between the two surfaces. Since evaporating molecules are much heavier than air molecules, and most of them have the same direction of motion, their collisions have little effect on the direction of flying and the rate of evaporation.
4. The molecules condense on the condensation surface, as long as there is a temperature difference between the cold and hot sides, and the form of the condensation surface is reasonable and smooth, it is considered that the condensation step can be completed, so it is also important for molecular distillation to choose a reasonable condenser form.

Since the materials entering the molecular distillation equipment are generally pre-processed materials, various impurities generated by the pre-treatment must remain in them. Among all the impurities, the corrosivity of hydrofluoric acid is relatively strong; although it is non-combustible, it will react with most metals to generate hydrogen gas and cause an explosion. In this case, it is necessary to use a complete set of molecular distillation equipment specially used for processing hydrofluoric acid-containing materials.

It is because of the special environment of high temperature and vacuum of molecular distillation equipment, plastic materials that do not react with HF cannot be used, and the metal materials of general manufacturing equipment such as 304 and 316 stainless steel all react with HF. Although platinum, gold, and silver do not react with hydrofluoric acid, they are too expensive to be used in the industry.

In view of the special environment of high temperature and vacuum, the molecular distillation and thin-film equipment are protected by spraying polytetrafluoroethylene compound, which not only ensures the strength of the equipment but also ensures the corrosion resistance of the equipment. The unique spraying process and structural design can Ensure that the coating does not come off in a vacuum and high-temperature environment.

For parts that are not easy to spray, non-metallic components are used locally for different functional requirements. For example, the heat exchange tube component is made of silicon carbide, which is stable and reliable in HF, and the heat transfer coefficient is 5 times that of stainless steel; and the structure is compact, safe, and durable.

For different HF-containing materials, while carrying out conventional process design, it will provide a one-to-one design for anti-corrosion according to the characteristics of different materials, to ensure the safe use of molecular distillation equipment and the smooth realization of the distillation effect.

Brief Analysis Of The Process Of Molecular Distillation To Achieve Material Separation