How to Use Pipettes

Before Use

It is important to check the marks, accuracy class and graduation tails before using pipettes.

Imbibition

Use thumb and middle finger of your right hand to pinch the upper end of a pipette, then insert the lower end into the solution to a depth of 10 mm to 20 mm. Use your left hand to hold a rubber suction bulb and connect it to the upper end of the pipette. Suck the solution slowly (Notice: In case of not diluting the solution, the sucked solution cannot be reflowed to the original bottle) and use the index finger of your right hand to take the pipette out.

Turn the pipette horizontally in order to make the solution touch above the graduation and replace the inwall water. Discard the solution from the lower end of the pipette and repeat washing for three times. Finally, you can imbibe the solution to a level of 5 mm above the graduation and use the index finger of your right hand to press the upper end of the pipette immediately.

Adjust Liquid Level

Lift the pipette out of the liquid level and use filter paper to clean the outer wall water. Lose your index finger a little bit to let the solution flow out slowly, then press the upper end of the pipette. Take out of the pipette and insert it into the container to absorb the solution.

Original Data Record

Normally, the relevant original data record of the pipette can be given to two decimal places.

How to Use Pipettes

Use And Precautions Of Diaphragm Vacuum Filtration Pump

Laboratory vacuum filtration equipment is specially designed for laboratory workers to maintain solid-liquid separation of liquid samples.

Operation Procedures of Diaphragm Vacuum Pump

1. Put the glass filter flask on the stainless steel workbench, and insert the silica gel plug of the funnel base into the filter flask.
2. Use pipeline to connect the pump’s connector with the filter flask.
3. Lay the filter membrane on the funnel base, cover the filter flask and rotate gently.
4. Connect the yellow bleeder tube with the bottom drain outlet of the filter flask, and use the fixture to clamp the bleeder tube.
5. Press the power switch to start the pump.
6. Use pressure regulating valve to adjust the vacuum degree (suction) and filtering velocity.

Precautions of Using Diaphragm Vacuum Pump

1. Check the voltage on the data plate of the pump, if it is in line with local voltage.
2. Please use the pump under clean, dust-free and draughty circumstances with the temperature lower than 40℃.
3. The pump must be operated on a horizontal table.
4. Please turn off the power before install and dismantle the silicone tube.
5. Do not move, hit or lean the pump when it is on the operation.

Use And Precautions Of Diaphragm Vacuum Filtration Pump

QuEChERS Prospects

After years of development, the QuEChERS pretreatment method has been continuously improved and broadened by researchers as a simple and rapid residual pretreatment technology.

The application target also has been extended from the highest moisture content of vegetables and fruits at the very beginning to agricultural and sideline products such as meat, milk, grain, oil, etc., and then to the soil, water, pollutants, etc. in the environment, and will be more widely used in various fields in the future.

At present, the extractant and purifying agent are relatively single, and the extraction and purification effects are not ideal for complex matrix samples. Moreover, due to the instability of some pesticides, the technique of using this method to treat multi-residue experiments is not mature enough.

In future research, new extractants and purifiers will be continuously developed. The ratio of extractant, purifying agent and water addition in different samples will be continuously improved, and high-sensitivity and high-throughput testing equipment will be continuously developed. The QuEChERS pretreatment method and various detection equipment combination technologies will become more mature and better to provide better technical support for pesticide residue analysis.

For choosing your QuEChERS packet, contact Hawach!

QuEChERS Prospects

Comparison Between SPE/FLASH and HPLC Column

Columns Ahead Statement

Generally speaking, SPE/FLASH is mainly applied to the pretreatment of samples.

People can easily perceive that SPE/FLASH columns separate salt and sugar, while HPLC ones can make glucose, maltose and sucrose apart from the sugar solution, which posses more similar properties to each other than salt and sugar do. Hence, the HPLC column requires higher power of stationary phases and separating with a corresponding higher prices.

Comparison Between SPE/FLASH and HPLC Column

 

The Differences Between The Filter Bag And The Extraction Thimble

The side of filter-bag where the filtrate comes out is dealt with special singeing treatment, which not only prevents the fibers from staying away from the polluted filtrate effectively but also avoids shortening the service life of the filter-bags caused by the excessive blockage of the filter holes that results in traditional roll pressing treatment.

Hawach filter bag is suitable for filtering general industrial liquids such as electroplating E, D paint, ink, paint, food, and other chemical medicinal liquids. And the bags are acid-resistant, alkali-resistant fibers which have high mechanical strength and can be used repeatedly. The filter bag applied to dust remover has excellent stability and heat resistance, which can represent the highest performance in the filter material industry. It is also the best kind of common filter materials. It has high filtration efficiency and accuracy. The commonly used filter materials are PE, PP, PTFE, PMIA, NMO, etc.

Hawach extraction thimble is a kind of cylindrical element used for filtering, which is generally used to filter gas medium and liquid medium. Compared with the filter-bag, the extraction thimble has some advantages. The extraction thimble occupies less space and is easy to clear. The extraction thimble has a longer life and lower cost.

The Differences Between The Filter Bag And The Extraction Thimble

Application Of Syringe Filters

Syringe filters are filters for standard lab samples, providing a fast, convenient and reliable way to filter samples. It is widely used in colloid separation, microanalysis, gravimetric analysis, and aseptic test.

Syringe filters handle chromatographic samples without introducing other impurities into the process. The material of the membrane and shell structure is very important. Because of the precision of the chromatographic system and the accuracy of the result analysis, it is very important to filter the samples.

Application of syringe filters
1. Sample prefiltration;
2. Clarifying and removing particles;
3. Liquid and gas filtration.

Syringe filters have different filter membranes (PTFE, PES, nylon 6, nylon 66 and PVDF) selection and each filter membrane has different apertures.
Common syringe filters include edge filters and ultrasonic filters:

An edge filter: the disadvantage of the traditional filter is easy blasting. An edge filter is suitable for ventilation, gas purification, gas sterilization, and water resistance.

An ultrasonic filter: it adopts new ultrasonic welding technology and new double-layer membrane design, which can filter large particles in advance, especially suitable for filtering large particles and multi-impurity materials.

Application Of Syringe Filters

Hawach PTFE Pleated Membrane Filter Cartridges

Hawach PTFE pleated membrane filter cartridges is made of polytetrafluoroethylene film and is widely used in gas sterilization filtration of pharmaceutical, biological products, food and beverage, and fermentation industries. The natural hydrophobic, double-layered PTFE membrane construction and 100% integrity testing ensure absolute sterilization of the media.

PTFE pleated membrane filter cartridges characteristics
1. Hydrophobic and hydrophilic PTFE membranes are available
2. Excellent resistance to organic and inorganic chemical corrosion
3. Can be used for strong solvent, strong corrosive liquid, strong oxidizing liquid, particle removal, sterilization filtration

Filter specifications
Standard sizes: 5”, 10”, 20”, 30”, 40″,…,70″
Filtration accuracy: 0.1um, 0.22um, 0.45um, 1um, 5um, 10um, 20um, 50um
The sealing ring is: silicone rubber, EPDM rubber, fluorine rubber, fluorine-containing rubber

Typical application
1. High-precision filtering of terminals in the microelectronics industry.
2. Low-temperature materials in refrigeration, such as liquid methane, liquid ammonia, and various refrigerants.
3. Weak acid corrosive materials in petrochemical production, such as water, ammonia, oil, hydrocarbons, etc.
4. Corrosive materials in chemical production, such as caustic soda, soda ash, sulfuric acid, carbonic acid, acetic acid, and ester acid.
5. Light-weight foods and pharmaceuticals that have hygienic requirements, such as beer, beverages, dairy products, and medical supplies.

Hawach PTFE Pleated Membrane Filter Cartridges