Application Fields And Related Descriptions Of Disposable Syringe Filters

The housing material of the syringe filter is made of sanitary polypropylene material, and the product structure is precisely designed to ensure smooth filtration, rational internal space, and a very low residual rate, thereby reducing the waste of samples.

The disposable syringe filter is a filtering tool routinely used in laboratories. It is used in HPLC sample preparation, routine QC analysis, protein precipitation removal, dissolution determination, food analysis, biofuel analysis, environmental testing.

The disposable syringe filter is a fast, convenient and reliable filter tool that is routinely used in laboratories. It has a beautiful appearance, light weight, and high cleanliness. It is mainly used for sample prefiltration, clarification and removal of particles, and sterilization and filtration of liquids and gases. It is a method for filtering small samples of HPLC and GC. According to the sterilization method, it can be divided into sterilization and non-sterilization.

The disposable syringe filter does not need to change the membrane and clean the filter, eliminating the complicated and time-consuming preparation work, and is widely used in the laboratory. The product is mainly used for sample pre-clarification, particle removal, sterilization filtration, etc.

Among them, the syringe filter is used in conjunction with a disposable syringe. It is a fast, convenient and reliable small-volume sample filter processing device that is routinely used in laboratories. Its filter diameter is 13mm and 25mm, and the processing capacity is from 10ml to 100ml.

Syringe filters are divided into disposable and multi-use, organic or water systems, and are used for sample filtration in liquid or gas phase analysis.

Filter materials of disposable syringe filter are: Nylon, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyethersulfone (PES).

Advantages of syringe filters

In HPLC analysis, the particle size of the chromatographic column packing is small and it is easy to be blocked by impurity particles. So, samples and solvents need to be pre-filtered to remove particulate contaminants and protect the instrument. Ion chromatography, which is commonly used in environmental analysis, also requires that no inorganic contaminants be introduced in sample pretreatment. Syringe filters is ideal for HPLC analysis and IC analysis. Filtering sample solutions is an important step in the sample pretreatment process.

·One of the shortcomings of traditional filters is that they are easy to burst. This product is specially designed to withstand a burst pressure of up to 7bar.

·The edge of the filter is threaded to prevent slippage, and the user-friendly design makes the operator handy.

·Stable membrane quality and zero difference between batches ensure the consistency of analysis results.

·The clear specification mark avoids confusion.

The syringe filter is suitable for the filtration of a small amount of samples in the laboratory. It has low adsorption of samples, thus ensuring the maximum recovery of small or high-value samples. The filter shell is made of polypropylene, welded by ultrasonic, and does not contain sticky Mixture, so it will not contaminate the sample.

Application Fields And Related Descriptions Of Disposable Syringe Filters

20l/50l Rotovap for Sale

 10l/20l/50l rotovap for sale is used for pilot scale test or medium sized production for evaporation, distillation, crystallization, concentration, alcohol removal, separation, and reflux.

50 liter rotovap consists of host with the motor, controller and display screen, electric heating bath, rotary flask, coil condenser, receiving flask, inlet, and deflation controller, vacuum gauge, PTFE sealing valves, and other connected parts.

The evaporation efficiency of large scale rotovap is affected by heating temperature, rotating speed, condensation, and sealing effect of the coil condenser.

Unlike rotary vacuum evaporators and rotary evaporator parts, large rotary evaporators are more suitable for industrial applications. For large scale rotovap, the RE120-W1/W2 series will be your best choice, with 10L, 20L, and 50L rotovap for sale.

Features of RE120-W1/W2 series industrial rotary evaporator:

1. The rotating speed can reach 120rpm;
2. Temperature can reach 99℃ for water bath;
3. Effective triple-flux coil condenser increased evaporation process;
4. Integral bath made of stainless steel with a protection layer which is safe to use and easy to clean;
5. Bath position can be lifted to adjust the position of the rotary bottle in the bath;
6. Seal ring of PTFE spring composite with the high vacuum;
7. Rotating bottle of 10l, 20l, and 50l rotovap;
8. Vacuum gauge is equipped as a reference to adjust accordingly;
9. Continuous receiving flask with discharge valve is equipped on this series to achieve continuous processing without changing the bottle.

Manual and automatic lifting type large scale rotovap to choose with the following specifications:

1. RE120-W1 series rotovap for sale
W1 large scale rotovap is for the main and subsidiary double reflux condenser with hand rotary lifting type.

20l/50l Rotovap for Sale

Guide to Flash Chromatography Column (Chapter 2)

 Guide to Flash Chromatography Column (Chapter 2)

4. Determine the appropriate ratio of silica gel to the compound. For simple separation, the ratio of the two is usually 30~50:1 (weight ratio); but for the more difficult separation, the ratio is as high as 120:1.

5. Choose a suitable flash separation column. The amount of silica you need determines the size of the separation column. Whether to use a short and thick or long and thin separation column.

6. Select the appropriate test tube for collection. This is also a good opportunity to consult experienced colleagues. But there is also a simple method: divide the volume of silica gel by 4, and then select a test tube that can hold this volume. (200mL silica gel corresponds to 50mL component).

7. Once you have selected the separation column, you need to block the bottom end of the piston to avoid the loss of silica gel. Usually, it can be done with a small ball of cotton or glass wool plus a long stick or glass rod.

8. Pack the flash separation column in the fume hood. Considering the use of a large number of volatile solvents and the health hazards of dry silica gel, it is not allowed to operate the flash column outside the fume hood. Check to make sure that the flash column is completely vertical. The inclined column is not conducive to separation.

9. Close the piston and add a few inches of eluent.

10. Use the funnel to add some sand (dry and washed) to the flash separation column. The purpose is to spread a thin layer of sand (no more than 1cm) on the plug, so as to prevent silica gel from falling into the collection bottle.

11. Measure the appropriate amount of silica gel. The safest way is to measure it in a fume hood. The density of silica gel is about 0.5 g/mL, so it can be measured directly in an Erlenmeyer flask (100g=200mL). Do not let the volume of silica gel exceed 1/3 of the flask, because we have to add solvent to it.

12. Add at least 1.5 times the volume of solvent to the newly measured silica gel, make it into a slurry, vigorously shake and stir it to make it fully mixed, and remove the gas in the silica gel (the presence of bubbles will make the flash separation column, the efficiency is greatly reduced).

13. Use the powder funnel to carefully and slowly move the slurry into the flash separation column, taking care not to damage the sand layer below. Pay attention to stop and shake the slurry from time to time during the grouting process to ensure that the silica gel is evenly mixed. After grouting, rinse the flask several times with the eluent and add the remaining solvent silica gel mixture to the separation column.

14. Use a dropper and eluent to rinse the silica gel stuck on the top edge of the flash column into the solvent layer.

15. When all the silica gel has been washed away from the flash column wall, open the piston and pressurize the column with compressed air. The silica gel in the column will be compressed to about half of its original height. Check to make sure that the top section of the column is flat. If it is not, it must be stirred again and then settled down. Under pressure, add excess eluent and tap the column gently with a pencil tip or rubber stopper. This will make the silica particles packed more tightly.

Collect all the eluate from the flash column and reuse it after adding the compound.

Note: Remember not to let the solvent level be lower than the filling layer.

Guide to Flash Chromatography Column (Chapter 2)

Calibrating Multichannel Pipettor To Prevent Errors

Calibrating Multichannel Pipettor To Prevent Errors

Widely used in chemistry, molecular biology research, and medical tests in the lab as well, a pipettor is a handy instrument for transporting a measured volume of liquid. It can draw up and dispense liquid by creating a vacuum above the liquid-holding chamber and releasing this vacuum. From single piece glass pipettors to complex adjustable or electronic pipettor, Hawach provides pipettors in several designs for various purposes, and in different levels of accuracy and precision too.

On one hand, a pipettor needs are accurate to the degree with the delivered volume being equal to the specified volume, on the other hand, for precision, it needs to be concerned with the closeness of several measurements to each other. For example, a pipettor might be consistently inaccurate but this inaccuracy could be very precise you still can get the reproducible result out of your samples.

The scientists always prefer the perfect pipetting with accuracy and precision for their applications. It is important to work hard to get maxim accuracy and precision and reduce the level of uncertainty at the same time. To reduce the risk of error in manual liquid handling, you need to choose Hawach pipetting system, consisting of the highest quality pipettors professionally maintained and calibrated. And they can be used with the high quality matched tips. With Hawach pipetting products on hands, the correct pipetting angle, speed, and a smooth, consistent pipetting rhythm will help you get better results.

In order to prevent errors when using a multi-channel pipettor, you must learn how to calibrate the main characteristics of the multichannel pipettor:
1. Large-sized central pipetting control button, independent tip removal button.
2. Ergonomically designed finger rest that fits the hand and is easy to hold.
3. Real one-handed operation-regardless of the left or right hand, you can easily set the pipetting volume with one hand.
4. Range lock to prevent unintentional range changes.

Calibration steps for multichannel pipettors
a. Adjust the pipettor to the volume to be calibrated and select the appropriate tip;
b.Adjust the balance;
c. Suck and blow distilled water back and forth 3 times to make the tip wet, wipe the tip with gauze;
d. Hold the pipettor vertically, immerse the tip into the liquid surface 2 ~ 3mm, and slowly (1 ~ 3 seconds) suck the distilled water consistently;
e. Remove the tip from the liquid surface and lean against the tube wall to remove the liquid outside the tip;
f.Put the pipettor into the weighing beaker at an angle of 30 °C. Slowly and uniformly press the pipettor to the first position, wait for 1 to 3 seconds, and then press it to the second position to completely discharge the liquid in the tip;
g. Record the weighing value;
h. Dry the outside of the tip;
i. Weigh 10 times according to the above steps;
j.Take the average value of 10 measurements as the weight of distilled water absorbed by the final pipettor, and calculate the volume according to the Z factor of distilled water listed in Appendix 1;
k. Adjust the pipettor according to the calibration result.
The above is all about sharing how to calibrate in order to prevent mistakes when using multi-channel pipettors today. I hope it will be helpful for everyone to use this device in the future.

Calibrating Multichannel Pipettor To Prevent Errors

What’s The Role Of Solvent Filter Played In Vacuum Filtration?

 What's The Role Of Solvent Filter Played In Vacuum Filtration?

Vacuum filtration apparatus is mainly used in liquid chromatography mobile phase filtration, particle matter analysis, and microbial contamination detection. They are standing equipment in chemical laboratories. Use borate glass or 316L sanitary stainless steel as the material, which can filter various aqueous solutions, organics, and corrosive liquids in the analysis, and can be autoclaved at 121°C.

HAWCH vacuum filtration apparatus includes vacuum filtration and vacuum pump. As an indispensable part of vacuum filtration, the solvent filter is a small device that removes a small number of solid particles in the liquid, which can protect the normal operation of the device. When the fluid enters the filter cartridge with a certain filter screen, its impurities are blocked, and the clean filtrate is discharged from the filter outlet. When cleaning is needed, just take out the detachable filter cartridge and reinstall it after treatment.

Solvent filter is suitable for precision filtration of solid and liquid in grease, petrochemical, pharmaceutical, pesticide, paint, food and beverage, chemical fiber, and wastewater.

Solvent filter operations
1. The solvent filter is fragile, so it must not be moved as a whole, especially with a clip.
2. The filter membrane must be qualified, and the unqualified ones will dissolve impurities. The solvent to be filtered can be soaked for 24 hours to see if there is any dissolution, so as to inspect the quality of the filter membrane.
3. The filter membrane is divided into organic and water systems, which should be distinguished.
4. For water filtration, organic membranes are used for organic membranes, and then mixed after filtration. For the mixed mobile phase, the membrane of a higher ratio should be used.
5. The membrane does not matter anyway, but the smooth side is up, and the rough side is down.
6. Do not discard the waste filter membrane at will. The filter membrane pollutes the environment and should not be solved. Collect for unified processing.
7. When pumping air with the oil-free vacuum pump supporting the solvent filter, do not wait for the liquid to be empty before pulling out the hose. It is not suitable to pull out, it will squash the hose and stop the pump when there is a little liquid left.
8. The filtered solvent should avoid secondary pollution.

Notes in the use of solvent filter

1. The flow capacity of the filter should be greater than 2 times the flow during normal operation;
2. When selecting a filter, pay attention to the reasonable selection of the filter;
3. Taboo oil flows in both directions in the filter;
4. The precision of the suction filter should not be too high;
5. The filter set in the pipeline should have a blockage alarm device;
6. The flow capacity of the return oil filter cannot be simply selected according to the pump flow;
7. When using water glycol media, a special filter must be selected.

Solvent filter maintenance

1. When installing the filter, pay attention to the direction of liquid flow marked on the housing, and install it in the hydraulic system correctly;
2. When the filter pressure difference indicator shows a red signal, clean or replaces the filter in time;
3. The filter should be cleaned or replaced regularly, and external contaminants should be prevented from entering the working system during cleaning and replacement;
4. When the filter is cleaned, the port should be blocked to prevent the cleaned dirt from entering the inner cavity of the filter and causing internal pollution;
5. Solvent filter failures are generally due to clogging of the filter or deformation, bending, flattening, and breakdown of the filter, etc. The repair method is to clean or replace the filter.

 What's The Role Of Solvent Filter Played In Vacuum Filtration?

Introduction Of Glass Fiber Extraction Thimbles

 Introduction Of Glass Fiber Extraction Thimbles

The glass fiber extraction thimbles are made of high-grade special ultra-fine glass wool and carefully processed by a special process. It is a high-efficiency filter device that collects harmful substances such as smoke, acid mist, and beryllium substitutes. Glass fiber extraction thimbles has the advantages of high-temperature resistance, low weight loss, high efficiency, and good strength.

Technical indicators

Temperature resistance: can withstand below 600 ℃. Resistance: 14-20mmHg. Efficiency: 99.9999% (for dust particles with a particle size ≥ 0.3 ч). Weight loss: 0.2%. The current extraction thimbles are all glass fiber (applicable below 400 degrees).

The weight must be weighed before the boiler dust sampling. In this process, it is best to dry and weigh in small batches. Because if it is a large batch, the opening and closing of the dryer cover during the weighing process will inevitably make it absorb moisture, which will increase the blank value and cause the measurement result to below.

Punching problem

Generally, there are two areas of the test hole that are not punched. One is on the horizontal pipe, in front of the base of the vertical chimney, and the other is on the vertical chimney. When the cross-sectional area of the flue is constant, it is considered that the location of the test hole is the same everywhere.

Because after the flue gas passes through the dust collector, the remaining part is only a part of the particulate smoke and the cold rail coil, so in the case of constant airflow, it generally cannot be completely settled.

For example, during a monitoring process, the glass screen printing machine, due to the opening of the plug, vibrated a part of iron filings. During the test process, I found that there were some iron filings in the extraction thimbles. Just imagine that the iron filings cannot be settled, not to mention the small Where’s the smoke? Therefore, when the cross-sectional area of the flue remains unchanged, the location of the test hole has little effect on the test result.

Of course, if there is a significant change in the cross-sectional area of the flue after the dust collector, it is better to punch the test hole at the end where the cross-sectional area of the flue becomes larger because this can make use of the larger cross-sectional area of the flue and slower airflow. Precipitating a part of smoke and dust, making the test result smaller.

What are the operating conditions of the glass fiber extraction thimbles?

Due to the characteristics of glass fiber, the following points must be paid attention to when using it. Before use, check that the two sampling heads are slightly blocked, slightly hooped, whether the taper is the same, matching, and the clearance is appropriate. When the extraction thimbles are loaded and unloaded, it is not affected by the force of tearing, shearing, etc., so that the extraction thimbles mouth is not broken.

If the glass fiber extraction thimbles are found to have voids, cracks, or uneven thickness, it cannot be used to avoid being blown by the airflow and causing sampling failure. It should be used within the specified temperature range to ensure that the extraction thimbles works under sufficient strength.

According to reports, when the glass fiber is heated to above 200°C and then cooled, its strength begins to drop continuously. After the fiber is heated to 510°C and cooled, its strength only maintains 35% of its original strength. The fiber can maintain high strength when heated, but after cooling, its strength is greatly reduced.

The glass fiber extraction thimbles have been widely used in China since it was put into production in 1974. Due to the use of glass fiber extraction thimbles, my country’s smoke and dust detection work has been greatly improved.

 Introduction Of Glass Fiber Extraction Thimbles

Introduction Of Glass Fiber Extraction Thimbles

Guide to Selection Of Sample Vials Septa And Cap

Although the sample vial is small, it is very learned. When something goes wrong with our results, the vial is always the last thing we think about, but it’s the first step. When choosing the right vial for your application, you need to make three decisions: the septa, the lid, and the vial itself.

1. Guide to the selection of septa
PTFE
Recommended for a single injection. Excellent solvent resistance and chemical compatibility. No resealing after a puncture. Long-term sample storage is not recommended.

PTFE/silica gel
It is recommended for multiple injections and sample storage. Excellent reseal properties. Chemical resistance of PTFE before puncture, and chemical compatibility of silica gel after the puncture. The operating temperature ranges from -40°C to 200°C.

Precut PTFE/ silicone
Excellent sampling reproducibility is achieved by providing good ventilation to prevent a vacuum from forming in the sample vial. Eliminate the blockage of the needle at the bottom of the sample. Good resealing ability. It is recommended for multiple injections. The operating temperature ranges from -40 ℃ to 200 ℃. No isolation pad PE. It has the same advantages as PTFE.

2. Vial cap selection Guide
There are three types of cap for sample vials: crimp top cap, snap cap, and screw thread top cap. Each sealing method has its own advantages.

Pliers flap
The sealing effect is very good and can prevent the sample from evaporating effectively. The position of the septa shall remain unchanged when the automatic sampler is pricking through sampling. The capping device is needed to seal the sample vial with a clamp cap. For a small number of samples, a manual gland is the best choice. For large samples, an automatic gland can be used.

Bayonet cover
The bayonet cover is an extension of the clamp cover seal. The plastic cover on the edge of the sample vial creates a seal by squeezing the septa between the glass and the extended plastic cover. The tension of the plastic cap is caused by its attempt to regain its original size. This tension creates a seal between the glass, the vial cap, and the septa.

The plastic bayonet lid can be closed without any tools. The sealing effect of bayonet cover is not as good as the other two sealing methods. If the cap fits very tightly, it can be difficult to put on and may break. If it is too loose, the sealing effect will be poor and the septum may leave the original position.

Screw cap
The screw cap is universal. Tightening the cap exerts a mechanical force that squeezes the septa between the glass vial edge and the aluminum cap. In the process of puncture sampling, the screw cap has an excellent sealing effect and supports the septa by mechanical means.No tools are needed for assembly. The PTFE/ silica gel septa of the screw cap are fixed to the polypropylene vial cap by a non-solvent bonding process. The bonding technology is designed to ensure that the septa stay with the cap during transportation and when the cap is placed on the sample vial.

This bonding helps prevent the septa from falling off during use, but the main sealing mechanism is still the mechanical force applied when the cap is tightly wound onto the sample vial. The mechanism of vial cap tightening is to form a seal and to keep the septa in the correct position during the insertion of the sampling needle. Do not screw the cap too tightly, as this will affect the seal and cause the septum to fall off and translocate. If the cap is rolled too tightly, the septa can become cupped or dented.

Small sample vial has so much exquisite knowledge, so is it clearer?
With the wide application of chromatography in detection, a large number of chromatographic sample vials need to be cleaned in the detection process, which not only wastes time and reduces working efficiency, but also results in deviation of experimental results due to the fact that the cleanness of chromatographic sample vials after cleaning does not meet the requirements. Therefore, choosing the right way to clean the sample vial is crucial!

Plan 1
1. Pour dry the sample solution in the vial.
2. Soak all 95% alcohol, rinse twice with ultrasonic and pour dry, because alcohol can easily enter into 1.5mL vials and can be inter dissolved with most organic solvents to achieve.
3. Pour in water and wash with ultrasonic twice.
4. Dry the lotion in the vial and bake it at 110 degrees Celsius for 1 to 2 hours. Never bake it at high temperatures.
5. Cool and store.

Plan 2
1. Rinse under running water several times.
2. Put it into a beaker filled with pure water and ultrasonic for 15 minutes.
3. Change the water and ultrasonic for another 15 minutes.
4. Soak in a beaker filled with or without water-ethanol.
5. Take out and air dry naturally.

Plan 3
1. Soak in methanol (pure by chromatography) for 20 minutes with ultrasonic cleaning, and then pour the methanol dry.
2. Then fill the chromatographic sample vial with water, ultrasonic cleaning for 20 minutes, and then pour the water dry.
3. After that, the chromatographic sample vial is dried.

Plan 4
1. Generally is the first rinse with clean water after drying with sulfuric acid dichromate potassium lotion immersion.
2. First, use medical alcohol to soak for more than 4 hours, then ultrasonic for half an hour, then pour out medical alcohol, use water ultrasonic for half an hour, rinse with water, and then dry.

Plan 5
1. If the cost is sufficient, it is best to use a new one every time.
2. If it is to be reused, the cleaning method is also very important. Firstly, soak in strong oxidizing cleaning solution (potassium dichromate) for 24 hours, then clean it three times with deionized water under ultrasonic conditions, and finally clean it once with methanol and then dry it.
3. The vial pad must be replaced with a new one, especially when analyzing pesticide residues, otherwise, the quantitative results will be affected.

Guide to Selection Of Sample Vials Septa And Cap