Overall Analysis Of Filter Bag

As one element of the filters, filter bag is a key part in the filtration process. In fact, the quality of the filter bag decides the filtering effect to a great extent. The materials for making filter bag include nylon, polypropylene, polyester, stainless steel and polytetrafluoroethylene.

Basically, there are many kinds of filter bags, such as liquid filter bag, air filter bag and so on. In specific, we will firstly talk about the liquid filter bag.

The ring of the liquid filter bag can be stainless steel, polypropylene and polyethylene plastics. The design of liquid filter bag includes all sorts of different bag bottoms and bag tops. The filter-out surface of it is processed by special singeing. This not only prevent the fiber from falling off and pollute the filtrate, and also avoid tradition al roll-in technology to jam the filtration bore and reduce the service life.

Furthermore, all the materials are raw white without any special bleaching process. The stable open hole ratio and sufficient strength ensure steady filtration efficiency and long operate time. Also, the liquid filter bag can provide the best filtration security. With the wide range of application, it is applied to the liquid filtration in all industries.

The filter bag has high collection efficiency for solid or colloidal particles. After special treatment, it can effectively prevent the fiber from getting out of the contaminated filtrate. The special double-needle sewing process ensures better filtration protection for each liquid filter bag. It is suitable for liquid filtration in various industries.

Overall Analysis Of Filter Bag

Management And Maintenance Of HPLC Columns

Hawach Scientific adheres to the principles of good faith, efficiency, and fairness to serve customers, and commit to the strictest quality standard in the production of HPLC Columns.

Hawach provides customers with various types and required HPLC Columns. Different batches and different columns all have good reproducibility, excellent separation effect and retention time. AR series can realize the function of the water column and phenyl column on the basis of C18. Compared with other current columns, Hawach columns have better performance in the analysis of complex alkaline compounds.

Usage of HPLC Columns

HPLC Column produced by Hawach Scientific is widely applied in the analysis of chemical drugs, biochemistry and clinical because of its high separation efficiency, fast analysis speed, good detection sensitivity, and can analyze different thermo-unstable physiological active substances with high boiling point and without vaporization.

In order to regulate the use and maintenance of HPLC column and guarantee the analysis quality of HPLC, Hawach makes an endeavor to improve column performance evaluation, information accumulation of application range and recipient and return management. Besides, Hawach columns are good choice for customers with easily controlled temperature, increased sensitivity and saved mobile phase.

Management And Maintenance Of HPLC Columns

The Selection Of SPE Cartridge

To select the appropriate SPE cartridge, we normally consider it from two aspects: the selection of adsorbent and specification of the cartridge. The use of appropriate adsorbent can achieve good separation between interfering substance and target component, and also meet the requirement of recovery. However, the mass of chemical compound which can be adsorbed by the adsorbent is limited, once the mass of the sample is too large, there can be overload which happens in the SPE cartridge, and therefore makes the target component directly go through the cartridge without being reserved.

Basically, we can select the adsorbent according to the properties of the target component and the substance. Moreover, for the concrete examples, we can also select the adsorbent which is based on the principle of “distinguish the target component and the main interferent”.

After selecting the appropriate adsorbent, we need to select the corresponding specification of the cartridge according to the volume of sample which needs to be determined. Because the mass of chemical compound which can be adsorbed by the adsorbent in SPE cartridge is limited, once the value exceeds it, the target component will not be reserved effectively. As a result, it is necessary to select the appropriate specification of SPE cartridge.

The Selection Of SPE Cartridge

Vacuum Filtration Apparatus Operation Process

Vacuum filtration manufactured in Hawach Scientific has better experience in laboratory tests due to the elimination of chemical and mechanical pretreatment, and the ratios of filtration areas are extraordinarily improved. It can ensure an accurate and professional test work under realistic conditions with advanced design and superior performance.

Through thousands of times tests, Hawach’s vacuum filtration can stand quality test. Hawach will work with you to select the best system components and accessories for your application. Hawach promises to tailor all vacuum filtration apparatuses to fit the specific needs of application.

HAWACH vacuum filtration components

Glass multiple connections: 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 connections: all stainless steel filter cup 316L, stainless steel filter head 316L, stainless steel Filter bracket 316L, stainless steel valve, aluminum alloy clip, dust cover, rubber plug.
Solvent filter: triangular liquid bottle (1L) sand filter, filter cup (300ml), fixing clip, dust cover, hose, hose linker.

Vacuum Filtration Apparatus Operation Process

Introduction And Advantage Of Syringe Filter

Hawach Scientific commits to produce syringe filter with excellent quality and good performance, which is achieved by adopting advanced detection means and production technology. Hawach syringe filter is an important step to filter sample solutions in sample pretreatment, and suitable for HPLC analysis and IC analysis.

High quality materials and exquisite workmanship perfectly guarantee the consistency of the analysis result and the sophisticated products.

Besides, the optimal design of product structure ensures the fluency of filtration, the rationalization of internal space and the very low residue rate, and greatly reduces the waste of samples.

Advantage of Syringe Filter

Hawach syringe filter provided by Hawach Scientific is simply quality filters, well packaged, and offered at a fair and competitive price. Compared with traditional Syringe filter, Hawach has gained some obvious advantages in many aspects.

An anti-skid function and a human-friendly design are obtained by provided with a thread on the edge part of the filter. Broad range of types and sizes can meet diverse application needs. The special construction allows particle shedding and minimal hold-up volume, which makes it ideally fit for the critical needs of different customers.

Introduction And Advantage Of Syringe Filter

How To Select Sample Vials?

As essential tools in laboratory, glass sample vials we offer always provide exceptional resistance to heat shock and chemical leaching. You can find them in a wide range of sizes and cap configurations.

Type I borosilicate glass assures content integrity. Due to the small boron oxide particles in the glass, the silicate is held more closely together, that make the glass much stronger to meet your needs in the lab. You can choose clear glass vials for best visibility and amber glass ones for protection from UV rays when you work with light-sensitive products and applications. And we guaranteed that all of Hawach vials, caps, and septa can work in your autosamplers perfectly.

Hawach sample vials are in three types: screw top, crimp top, snap top. Suitable for research studies, screw-top sample vials are critical to the stability of the glass. The crimp top sample vials can provide a larger target area to improve the accuracy of the autosampler needle. And snap top sample vials can be easily applied and removed by hand.

How To Select Sample Vials?

About Usage, Feature And Working Process Of Flash Column

FLASH column is a sample pretreatment technology developed by the combination of liquid-solid extraction and column liquid chromatography. It is mainly used for sample separation, purification and concentration which has been widely used in medicine, food, environment, commodity inspection, chemical and other fields.

Feature

Compared with the traditional liquid-liquid extraction method, flash column can improve the recovery rate of the analyte, separate the analyte from the interference component more effectively and reduce the sample pre-treatment process. It is easy to operate, time-saving and labor-saving.

Working process

Flash column adopts the separation principle of liquid chromatography separation for selective adsorption and selective elution. The frequent used method is as follows:

1. A sample comprising an isolate and an interferent passing through an adsorbent;
2. The adsorbent selectively retains the isolate and some interferents, and the other interferents pass through the adsorbent;
3. The adsorbent is rinsed with a suitable solvent to selectively elute the previously retained interferent, and the isolate remains on the adsorbent bed;
4. The purified, concentrated isolate is rinsed from the adsorbent.

About Usage, Feature And Working Process Of Flash Column

Membrane Separation Technology In Medicine Preparations

At present, membrane separation technology has been widely applied in the medical industry, especially the preparation of oral agents and injections of traditional Chinese medicines. Thus, customers need to know more details about this technology.

Technical Features

Firstly, membrane separation technology can be used to differentiate and concentrate on heat-sensitive substances in a normal temperature environment. It has a very low energy consumption rate while providing a high separation efficiency.

It could retain the active ingredients during the extraction process of the drug. Besides, it can maintain a superior environmental protection effect. It can realize the automatic separation of substances, which is easy for the operators to implement and carry out.

At present, membrane separation technology has been widely applied in the medical industry, especially the preparation of oral agents and injections of traditional Chinese medicines. Thus, customers need to know more details about this technology.

Technical Features

Firstly, membrane separation technology can be used to differentiate and concentrate on heat-sensitive substances in a normal temperature environment. It has a very low energy consumption rate while providing a high separation efficiency.

It could retain the active ingredients during the extraction process of the drug. Besides, it can maintain a superior environmental protection effect. It can realize the automatic separation of substances, which is easy for the operators to implement and carry out.

Membrane Separation Technology In Medicine Preparations

Assembly And Operation Of Pipette

One of obvious features is that pipette produced by Hawach Scientific is intuitive to use and simple to clean, and the assembly process is easy. It is designed for convenient disassembly and reassembly.

All parts that contacts with liquids is easy to clean and provide with the good autoclavable property because the manufacturing materials are of high temperature and pressure tolerant structure. New elastomeric seals and polymer tip ejectors deliver smoothness and control. Lightweight and designed for use with both hand, and carefully shaped finger hook presents a relaxed grip.

Advanced design of Pipette

Hawach’s pipette blends cutting edge innovation and engineering to deliver superior reproducible results with extraordinary comfort. Secure volume lock allows convenient one-hand adjustment and averts potential drift. It brings excellent hand comfort and less fatigue while maintaining supreme accuracy and precision.

All components are removable and convenient to clean and maintain. The diverse volume ranges and complete types of pipettes can assure you of high quality. What’s more, the built-in streamlined tip ejector is beneficial for convenient tip ejection and wider access to the narrow neck containers.

Assembly And Operation Of Pipette

QuEchERS, A Tool In Pretreatment Of Pesticide Analysis

QuEChERS, the abbreviation of Quick, Easy, Cheap, Effective, Rugged and Safe, is a widely used and effective method because of the variety of pesticides and the detection samples. QuEchERS is widely used in the pretreatment of pesticide analysis due to its high recovery and accuracy, simple operation and low pollution for a large number of polar and volatile pesticides. It is simply summarized as the process of extraction, purification, and extraction.

The first step is the extraction.

Add 10 ml acetonitrile to the sample containing 10 g, and then add internal standard and shake it. Add 4 g MgSO4, 1 g NaCl, 1 g trisodium citrate hydrate, 0.5 g disodium citrate hydrate, shake it for 1 minute, then centrifuge the sample for 5 minutes at 3000 U/min.

The second step is purification.

One is the decentralized SPE purification process. Transfer 1 ml supernatant to the centrifugal tube containing 150 mg MgSO4 and 25 mg PSA, shake it for 30 seconds and then centrifuge for 5 minutes at 3000 U/min. Preserve it in acetonitrile solution containing 5% formic acid. And for GC/MS detection, it requires conversion solvents.

The other is the extraction column purification process. Elute the PSA and GCB double-layer composite columns with 5 ml toluene and transfer supernatant to the column. And then collect the solvent. Then elute with 6-12 ml 3:1 acetone: toluene solvent, and analyzed by GC/MS after concentration.

QuEchERS, A Tool In Pretreatment Of Pesticide Analysis

One Kind Of Vacuum Filtration From HAWACH–Vacuum Pump

A vacuum pump is a device that uses a mechanical, physical, chemical, or physicochemical method to evacuate a pumped container to obtain a vacuum. Generally, it uses diverse methods to create and maintain a vacuum in an enclosed space. According to the working principle, the vacuum pump can basically be divided into two types, namely, an air trap pump and an air transfer pump, which is widely used in many industries, like the chemical, food, electronic coating, and metallurgy.

Features of HAWACH vacuum pump
At HAWACH, there are two series of vacuum pumps and the 033A vacuum pumps and 050B vacuum pumps are the best sellers, with the pumping speed 20 and 30 respectively. The following features make HAWACH vacuum pump popular in the market.

1. Cutting-edge design and technology bringing higher work efficiency and longer service life.
2. No pollution, requiring no working medium.
3. Motor quality guaranteed, supplied by ODM, a professionally exported motor manufacturer.
4. Equipped with a thermal power-off protector.
5. Frictionless membrane movement, no heat generation, and no friction loss.
6. Automatic cooling exhaust system adopted to ensure continuous operation for 24 hours.

One Kind Of Vacuum Filtration From HAWACH–Vacuum Pump

Flexible Control Of Bottle-Top Dispenser

For use with a wide range of compatible liquids, including inflammable and corrosive liquids, bottle-top dispenser marketed by our company can be widely used in biology, pharmaceutical, clinical, and chemical labs. It is also fit for application in a variety of liquid reagents while providing superior sealing over a wide range of temperature. It is available in four different volume ranges, from 0.5 to 5 ml, 1 to 10 ml, 2.5 to 25 ml, and 5 to 50 ml.

Characteristics of Bottle -Top Dispenser
Bottle-top dispenser marketed by Hawach Scientific is characterized in good chemical tolerance, high-temperature disinfection and sterilization, and high-pressure resistance. The bottle is made of PTFE\ FEP\ BSG\ PP, which gives it maximum viscosity resistance. It is convenient to operate and maintain.

In addition, the upper and lower piston and plunger provide good sealing resistance, and this ensures the accuracy of the distribution process. Improved fluid technology makes liquid absorption faster, and the build-in sawtooth guideway enhances the repeatability of the volume setting. Complete accessories do good to perform special liquid distribution work such as aseptic operation or extraction from large containers.

Advantages of Bottle-Top Dispenser

The convenient design ensures the simple and economic operation of the bottle-top dispenser. The smooth and precise piston moves up and down to make the operation convenient and comfortable.

Drainpipe helmet is easy to disassemble and install even wearing gloves and simultaneously avoids accidents or contamination caused by human contact with reagent. The transparent suction tube is suitable for all sizes of reagent bottles. Precise calibration design is conducive to the rapid design of volume.

Flexible Control Of Bottle-Top Dispenser

Brief Introduction Of Filter Paper

Function
Filter paper is a kind of special paper with excellent water-absorbing quality and filtration performance. The filter paper commonly used in the analytical laboratory is taken as a filter medium to separate the solution from the solid.

Types
Now, the domestic filter papers can generally be divided into three types–qualitative analysis, quantitative analysis, and chromatographic qualitative analysis. The two concepts of quantitative filter paper and qualitative are all available in cellulose filter paper and are not suitable for other types of filter paper such as glass microfiber filter paper.

Qualitative filter paper is frequently adopted in qualitative chemical analysis and corresponding filtration separation. It is generally used to filter the solution in a qualitative test that does not require the calculation of chloride, sulfate, etc.

Quantitative filter paper is used for precision calculation of numerical values, such as determination of residue, insoluble matter, etc. After the general quantitative filter paper is filtered, it needs to enter the high-temperature furnace for processing.

Chromatographic qualitative analysis filter paper is mainly used as a support in paper chromatography analysis with fast, medium and slow speed.

Brief Introduction Of Filter Paper

When You Purchase Pipettes

What do you need to consider when you are purchasing pipettes? Of course, first of all, we consider the performance of the products and its durability. Then we consider the ergonomic design. Today we are going to talk about several important points when you purchase pipettes.

Products performance:
Products performance means accuracy and repeatability, which is very difficult for customers to test. In that case, you need to judge according to the technical data and refer to the written material from the manufacturers.

Durability:
It depends on the material of the products. The housing should have impact resistance, corrosion resistance, and low thermal conductivity. There are different kinds of a piston made of stainless steel, ceramic and plastic. Of course, better material, higher price. So you need to make an overall consideration.

Hawach is the design, sale, laboratory services set in one of the high-tech enterprises, and enjoys great market reputation. In order to provide the best services to our customers, we have one-to-one technical personnel to offer you technical guidance. Click www.hawach.com We are happy to wait for your consulting.

When You Purchase Pipettes

Brief Introduction Of Flash Column

Flash column is a sample pretreatment technology developed by the combination of liquid-solid extraction and column liquid chromatography. It is mainly used for sample separation, purification, and concentration which has been widely used in medicine, food, environment, commodity inspection, chemical, and other fields.

Principle
Flash column adopts the separation principle of liquid chromatography separation for selective adsorption and selective elution. The frequent used method is to pass the liquid sample solution through the adsorbent, retain the substance to be tested, and use the appropriate strength solvent to wash away the impurities, and then quickly elute the test substance with a small amount of solvent, thereby achieving the purpose of rapid separation, purification, and concentration.

It is also possible to selectively adsorb the interfering impurities and let the measured substance flow out; or simultaneously adsorb the impurities and the tested substance, and then selectively elute the test substance with a suitable solvent.

Brief Introduction Of Flash Column

Filter Media For Filter Capsule

The filter capsule is also called the submerged filter, it uses a folding membrane with a large filter surface area. It is suitable for the filtration of a large volume of solution.

The shell of the filter capsule is made of polypropylene and does not contain any adhesives and other chemicals. This ensures zero pollution to the samples. In the meantime, the filter capsule provides different bore diameters for the user’s choice, and it can be autoclave sterilized.

According to different characters of the filtering objects, the filter capsule adopts different filter mediums. In general, the hydrophobicity polytetrafluoroethylene membrane is suitable for filtration of the solvent, corrosive solution, air, and air vent.

When referring to hydrophilic polypropylene membrane, it is mostly applied to the filter capsule which is for reverse osmosis, ultrafiltration and ink filtration. Basically, it is also suitable for filtering water solution and solvent sample.

Also, some filter capsules select nylon membrane with the characters of high flow rate and low level of extractable matter. By using the prefilter medium which contains glass fiber, it can extend the service life of nylon membrane.

Commonly, the filter capsule with nylon membrane is suitable for filtration of samples with large volumes and which are difficult to be filtered.

Filter Media For Filter Capsule

Types And Performance Of Membranes Filter

A wide range of pore size and materials such as PTFE, PVDF, Nylon, PP, MCE are available, which gives customers more choices.

Nylon membrane filters are suitable for use with high PH samples; PES membranes filters are fit for filtration of compatible organic solvents and aqueous samples; PP membrane filters are widely used in analytical and research applications for the pharmaceutical, environmental, biotechnological, and agricultural industries; PVDF membranes filter are often used for purity during sterilization speed.

Performance of membranes filter

Different types of membranes filter provide diverse performance. In terms of thickness, PP is 160 to 230um, Nylon is 90 to 140um, PES is 110 to 140um, PVDF is 90 to 100um. As for maximum operating pressure, all of them are in 1.5 or 4.2 bar@23℃.

Compared chemical compatibility, PP is aqueous, and can act with mixed solvents; PES is used with strong bases, alcohols, protein, and peptides; Nylon is aqueous and fit for organic solvent and mixed solvent; PVDF is used with aggressive solvents, strong acids, alcohols, bases, and aromatics. Other detailed information is provided on our official website.

Types And Performance Of Membranes Filter

Selection Of SPE Cartridge

During the sample pre-treatment process, except for the selection of SPE cartridge sizes, there are still several factors that should be carefully considered.

Specification of SPE Cartridge

The first important factor to select an SPE cartridge is the filler. The principle is to ensure that the filler of the SPE cartridge has sufficient capacity to retain the target compound 100% on the column. On the other hand, the filler shall not be too much. The more the amount of the filler, the greater the amount of eluent will be required, which could be adequate for the target compound to be effectively eluted.

The capacity of the bonded silica cartridge is generally from 1% to 5% and the ion exchange cartridge is about 0.5 to 1.5 meq/g. Since there are many interferents except for the target compound, it is recommended that the filler capacity is more than twice the target compound content.

Pre-treatment Solvent Selection

For a reverse-phase cartridge or an ion exchange cartridge, the methanol or a polar organic solvent can usually be used as a pretreatment solution. Water or a buffer solution could be used as an equilibrium solution. For the pre-treatment of the normal-phase column, an elution solvent or a non-polar organic solvent would be a better choice.

Washing Solution Selection

If the target compound is a neutral compound with a selected hydrophobic non-polar filler (such as C4, C8, C18, etc.), the cartridge can be washed with water or a buffer used for column equilibration. If the analyte has strong adsorption on the SPE cartridge, a water-soluble organic solvent may be added to the washing solution to enhance the washing effect.

Selection Of SPE Cartridge

Pipettes Calibration And Selections

Pipettes is a graduated glass tube using to transfer a small volume solution. As a ubiquitous tool in laboratories, pipettes come in many shapes and sizes. They are produced by many different manufacturers, but they perform the same functions, usually with specifications of 1ml, 2ml, 5ml, 10ml and so on.

Types of pipettes:

Incomplete efflux pipette, with the zero graduation above.
Complete efflux pipette, with the zero graduation above or down.
Blow out type, with the fast flow velocity.

Pipettes calibration and selections:
Pipettes calibration is considered an essential part of laboratory regime. It is used to transfer or dilute precise volumes of fluid. So it’s very important to understand accuracy and precision. If you are looking for the best selection at unbeatable prices, Hawach as a very famous brand having a reputation, search www.hawach.com, and you will find the most comprehensive products.

Pipettes Calibration And Selections

About The Maintenance Of Vacuum Pump

The importance of maintenance

The quality of a vacuum pump depends on its mechanical structure and the quality of the oil. It must be protected when using a vacuum pump. If the organic solvent with high volatility is distilled, the organic solvent will increase the vapor pressure by the oil absorption, thereby reducing the pumping efficiency. The acid gas, if it is will corrode the oil pump. If it is water vapor, it will make the oil into an emulsion and bring damage to the vacuum pump.

Points needing attention

Therefore, the following points must be paid attention to when using a vacuum pump:
1. An absorption device must be installed between the distillation system and the vacuum pump.
2. The steam of the organic solvent in the system must be completely removed by a water pump before distillation.
3. If you can pump with a water pump, try to use a water pump. If the distilled material contains volatile substances, you can use a water pump to depressurize and then use the oil pump.
4. The pressure relief system must be kept airtight. All rubber stoppers should be of suitable size. 5. The rubber hose should be vacuum hose. The ground glass is coated with vacuum grease.

About The Maintenance Of Vacuum Pump

The Standards and Characteristics Of Extraction Thimble

and inspection of filter cartridge dust collector.

Inspection rules, labels, packaging, transportation, storage, etc.
This standard is suitable for the use of synthetic fiber nonwoven filter material, paper filter material, and synthetic fiber nonwoven filter material, paper filter material as the base material for membrane filtration.
The design and manufacture of filter barrel type dust collector with filter element made of the material.
This standard is not applicable to explosion-proof type.

Reference criteria

The provisions contained in the following standards constitute the provisions of this standard by reference to them. At the time of publication of this standard, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest version of the listed standards.

Characteristic of extraction thimble

1. Improving the effective filtering area greatly;
2. Guarantee a low and stable pressure difference and increase the flow rate of the air;
3. The filter element is compact and easy to install;
4. Particularly suitable for industries with high dust concentration.

The Standards and Characteristics Of Extraction Thimble

To Know More About Hawach And Vacuum Filtration

HAWACH and its core principles

HAWACH focus to become the BEST they can revolve around its 4 CORE PRINCIPLES. They are TRUST, ANTICIPATE, KNOWLEDGE and CUSTOMER FIRST.
Trust means an unwavering commitment to our customers and colleagues to provide the best value of products and services in the industry.

Anticipate: we keep customer’s needs in mind and make them complete satisfaction.

Knowledge: its commitment to acquire knowledge of its products through training, continuing education and best practice sharing.
Customer-first is to make customer experiences the best possible interaction each and every time.

Vacuum filtration
Filtration is a technique used to separate a solid from a liquid and is used in many experiments. Though filtration can be done simply with gravity, more often vacuum filtration is employed because it is much faster. HAWACH is home to two different kinds of vacuum filtration: vacuum device (including glass and stainless steel) and vacuum pump.

To Know More About Hawach And Vacuum Filtration

Details On Syringe Filter

Syringe filter designed by Hawach Scientific overcomes many defects of current syringe filter, it provides with low extractable and particle shedding, handy and really available, easy operation, economical and disposable, it can be available in non-sterile and sterile condition.

Therefore, those improved properties endow it wide applications, such as sample filtration, liquid sterilized filtration or clarification, particle removal filtration, gas sterilized filtration, and even general sterile filtration of gases and air.

Details on Syringe Filter

Hawach syringe filter is an update on original design. In keeping with its tradition on innovation, Hawach is committed to improve classic design to offer higher performance and quality. Hawach provides high quality syringe filters with color coding for quick and easy identification, and develops wide selection of syringe filters which helps customers to filtrate bigger particles and allows filtering more than average filter.

Hawach syringe filter are available with many different membrane including Nylon, PTFE, PES, PVDF, MCE, CA, GF and so on, in both sterile and non-sterile varieties, and with or without pre-filters. Options include different diameters, membrane types, and sterile filters in blister packs for different applications.

Details On Syringe Filter

The Technology And Application Of SPE

SPE is the abbreviation of Solid Phase Extraction. It is a technology of sample pretreatment which is developed in recent years. Specifically, SPE technology is an integration of liquid-solid extraction and column-liquid extraction technologies.

It is mainly applied for the separation, purification, and concentration of the samples. In comparison with the traditional liquid-liquid extraction, the solid phase extraction technology can avoid a lot of problems. For example, easy emulsification, incomplete phase separation, the low recovery rate of quantitative analysis, expensive and fragile glassware and large amounts of organic wastewater.

Nowadays, solid-phase extraction technology can easily deal with multiple samples at the same time. It greatly reduces the workload and operation time of the sample pretreatment. Also, the working efficiency is largely improved. On the whole, the SPEtechnology has the advantages of easy operation, accurate, timesaving, save labor, environment protecting, and so on.

Furthermore, the solid-phase extraction cartridge can separate the target analyte from the interfering component more effectively. It can improve the purity and recovery rate of the target analyte, reduce the relative deviation and increase the reproducibility. Also, the SPE cartridge is good for making more accurate qualitative and quantitative analyses on the target analyte.

The Technology And Application Of SPE

Use Precautions for HPLC Reversed-Phase Columns

The HPLC reversed-phase column is made of high-purity and high-strength silica gel by using advanced bonding technology. It has a high surface bonding rate and good peak shape for alkaline and acidic compounds. With a high column capacity and long service life, it is the one for the clients at a low cost.

Performance Advantages

The HPLC reversed-phase column could be used in both positive and negative phases. It has a stable high coverage single-bond phase and the fully capped sphere. Also, it possesses low hydrophobicity, due to the presence of cyano groups, there is a unique selectivity provided.

Precautions For Using Buffer

The first aspect that should also pay attention to while using an HPLC reversed-phase column is to avoid the use of hydrochloride, which is corrosive to steel. Secondly, it prefers to prepare the buffer solution when it is needed. Usually, the buffer solution is the fungus culture solution, which indicates that there would be some strange phenomena if the experiment is conducted in the next day or a long time.

It is necessary to know the pH range in time. During the long term use of buffer solution, it is essential to observe whether there is any precipitation. If there is any white salt precipitated, the 10% nitric acid flushing liquid can be used regularly to avoid blockage.

Use Precautions for HPLC Reversed-Phase Columns

About Filter Paper Selection And Types

There are three factors needing to consider in filter paper selection:

1.Effective area: the larger the effective area, the larger the dust holding capacity, the smaller the resistance, and the longer service life. And of course, the cost is correspondingly increased.

2.Fiber diameter: The finer the fiber diameter, the better the interception effect and the higher filtration efficiency.

3.The content of the binder in the filter material: The high content of the binder means high tensile strength of the paper and high filtration efficiency. The phenomenon of hair loss rare appears, with small dust, but the resistance increases accordingly.

Types of filter paper

There are two types of filter paper: qualitative filter paper and quantitative filter paper. The difference is the amount of ash after ashing. The qualitative filter paper ash is less than 0.15%. The quantitative filter paper ash is less than 0.01%.

The filter paper whether qualitative or quantitative can be divided into three types: fast speed, medium speed, and slow speed. The difference lies in the nature of the precipitation property of the separated material. Fast filter paper is suitable for colloidal precipitation and slow filter paper for crystal precipitation.

About Filter Paper Selection And Types

The Types Of Microporous Filter Membrane

The microporous filter membrane is mainly applied for the analysis of samples, especially for the filtration of the mobile phase and samples in the chromatographic analysis. It has a good effect on protecting the chromatographic column, infusion pump pipeline system and sample valve from not being polluted.

It is widely used in the gravimetric analysis, microanalysis, colloid separation, and sterility test. In general, it should be noticed that when choosing the filters, we should choose appropriate microporous filter membranesaccording to the physical and chemical properties of the filter media.

For example, the regenerated cellulose filter membrane is made of natural cellulose which is reformed after chemical processing. This kind of membrane tolerates high temperature in autoclave sterilization as well as processing by all sorts of organic solvent.

However, it cannot be used in the water media. If we must process the filtering medium with a little water, in order to avoid excessive expansion, we must put the membrane in the filter and tighten it with ethyl alcohol before use.

Moreover, the polytetrafluoroethylene filter membrane has extremely stable chemical properties. It can tolerate strong acid, strong base, a strong oxidant, all kinds of corrosive liquid and organic solvent. The operating temperature ranges from -180 ℃ to 250 ℃.

The Types Of Microporous Filter Membrane

How to Choose the Right Syringe Filters

As single-use, membrane-based tools widely used in the lab, syringe filter are perfect for removing particulate impurities from small liquid and gas samples. Considered for different application, disposable syringe filters are well known because of its fast and efficient filtering, material purifying ,and sterilizing. And it is the best choice for filtering HPLC and GC small quantities.

Hawach have three series of syringe filter: Winstar series syringe filters, Filtster series syringe filters and Sterile series syringe filters. You can select either a sterile or non-sterile filter to remove particulates from a liquid sample depending on the aim of the application. 

With clear color and ultrasonic welding, Hawach Filtstar series of advanced syringe filters are introduced in many media materials and sizes. Designed with the color code, Hawach Winstar syringe filters are adopted with standard female Luer lock and male roller accessories. And Hawach Sterile syringe filters are available in wide variety of filter membrane materials, include  PTFE, PP, PVDF, Nylon, PES, MCE, CA and glass fiber.

When you get the right kind of Hawach syringe filter, you can draw your sample into the syringe and attach the filter to the syringe end. After that, you can push a few drops through the filter as while as you hold the syringe with the filter pointing up. The third step is to place the filter tip over the container, apply positive pressure and push the sample through the syringe filter gently.

How to Choose the Right Syringe Filters

Use Method Of Gas Sample Vial

It is well known that there are lots of types of sample vials applied to the storage and detection of different samples. What would be introduced below is the use of instruction of the sample vial for gas determination.

Use procedure

The first step is to connect the inlet valve of the sample vial to the sampling hose while all the other valves are closed. Meanwhile, remember to rinse the hose with the sample by opening the control valve and outlet valve. After completing the rinse process, partially fill the vial with a liquid phase sample when the control valve is closed.

Partially discharge the gas phase sample from the outlet valve before it is closed. And then discharge the residue of the liquid phase by opening the outlet valve once again. Repeat this process at least three times. Finally, close the inlet valve and the control valve and remove the connecting hose after the liquid phase sample is filled in the vial.

Inspection

Check carefully the pressure change in the sample vial. If the pressure exceeds 4Mpa, then the vial should be released immediately to a pressure lower than 4MPa. The next one is the leakage check. Immerse the vial in water and check for leaks after draining a specified amount of liquid samples. the sample should be discarded if there is any leakage. The samples should be stored in a cool place until all tests are completed.

Use Method Of Gas Sample Vial

Do You Know All The Basics Of Flash Column?

Definition

Flash column is a cost-effective technique to separate mixtures of molecules into their individual constituents, and it is more frequently used in the drug discovery process. It is able to separate substances based on differential adsorption of compounds to the adsorbent; compounds move through the column at different rates, allowing them to be separated into fractions.

Principle

The principal behind flash column is simple-due to their particular chemistry-polarity differences, compounds in solution will separate from each other, given the right conditions and technique. These chemical differences are based on each compound’s solubility in a particular solvent. Compounds with lower solubility can be removed from those with greater solubility using the same solvent.

Separation process

To separate, it uses a column filled with a pure, solid medium such as synthetic silica onto which the chemical mixture is introduced. The solvent is introduced into the column by a pump after the mixture is added to the top of the column. Those compounds that have higher solubility will migrate through the column faster than those with less solubility and can be collected individually. The collected materials will be purer than before.

Do You Know All The Basics Of Flash Column?

Description And Application Of Membranes Filter

Description of Membranes Filter

Membranes filter is frequently used for purity during clarification and sterilization procedure, it is often fit for general biological filtration, particle retention, and removal for aqueous solutions. Membranes filter provided by Hawach scientific are available in two types: one is roll type, and another one is round disc type.

Both of them are biologically inert with good thermal stability and provided with good chemical compatibility. Besides, it can accommodate a wide range of applications, especially those requiring high flow rate, and applications where a membrane with a relatively high nonspecific adsorption.

Application of Membranes Filter

Membrane filter marketed by our company enjoys a good reputation in quality and performance aspect. It is perfect for filtration of air, gases or chemicals. In view of performance, it is characterized in excellent optical visibility, high filtration speed, and low non-protein adsorption of proteins. The wide selection of diameters and pore sizes meet different needs of customers.

The high standard of workmanship and selection of materials make them excellently for the particle removal from solvents, allow their capillary pore structure to be uniform and precise, and make a membrane with a narrow pore size distribution, thus they are excellent for precise particle retention and analysis.

Description And Application Of Membranes Filter

Use Precautions Of Pipette

It is very crucial to correctly and properly use the pipette, which is worthy of being paid great attention to from the operators. To prevent the pipette damage and personal injury, to learn about the use of precautions is very necessary.

Pipetting Precaution

First of all, remember do not pipette if the tip is not installed. At the beginning of the sample pipetting operation, it is necessary to keep it slow and stable by preventing the sample from entering the solution extractor, in case of the occurrence of air leakage due to the excessive speed. To obtain high precision, it is essential to extract the sample solution once before the formal pipetting, especially when dealing with the serum protein solution or organic solvent.

It is possible to form a “liquid film” on the inner wall, which would cause a small drainage volume. In particular, it is strictly forbidden to extract solutions with strong volatility and strong corrosiveness, such as concentrated acid and alkaline.

Use Precautions Of Pipette