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Wednesday, September 25, 2019

General requirements for adsorbents: large surface area and certain adsorption capacity. Does not chemically change with the developing agent, does not react with or catalyze, decompose or associate with the substance to be separated, and the particles are uniform. Silica gel and...

Tuesday, September 24, 2019

Ion Chromatography is one of high-performance liquid chromatography (HPLC) and is a liquid chromatography method for the analysis of anions and cations. In a narrow sense, ion chromatography is a chromatographic method in which a low exchange capacity ion exchange resin is used as...

Monday, September 23, 2019

The reason for the QuEChERS matrix effect in the liquid state is generally considered to be due to the non-volatile components in the matrix and the substance to be tested, which competes in the ionization process. The matrix effect in gas phase temperament is generally attributed...

Monday, September 23, 2019

Let's take a look at two common adsorbents for adsorption chromatography. Polyamide The polyamide adsorbent can be divided into nylon 6 (polycaprolactam) and nylon 66 (polyhexamethylene adipamide), which are hydrogen bond adsorption and semi-chemical adsorption. There are many amide...

Friday, September 20, 2019

Hawach Scientific company specializes in the production of PES filter membrane, stable quality, products exported to Europe, North America, and other countries. We have more than 16 years of experience in the filtration industry. Pore size : 0.1um /0.22um/0.45um/0.65um/0.8um/1.2um Diamter ...

Thursday, September 19, 2019

The determination of 10 plant polyphenols in tobacco samples by solid phase extraction and high-performance liquid chromatography as below: Plant polyphenols are important substances in tobacco. The content of polyphenols in tobacco has an important influence on tobacco quality. Therefore...

Wednesday, September 18, 2019

Selection of scavengers The conventional QuEChERS method only uses PSA which is too simple single that can no longer meet the complex matrix samples examination experiments. GCB (graphitized carbon black) can effectively adsorb pigments, non-polar interferences such as sterol due...

Monday, September 16, 2019

Hawach Scientific provides a wide selection of flash columns, they are a quick and easy way to separate complex mixtures of compounds, and often used on a preparative scale to provide better separation and cuts down on the amount of time required to run column. We committed to providing...

Monday, September 16, 2019

Reversed phase chromatography (RP) is the most widely used technique in high-performance liquid chromatography (HPLC) up to now, mainly because it is suitable for the analysis of most of them. Nonpolar substances and many ionizable and ionic compounds. Most stationary phases used...

Friday, September 13, 2019

Some samples (such as avocado, peanuts, olive oil, etc.) contain more fat. Due to the limited solubility of fat in acetonitrile, the recovery rate of some fat-soluble pesticides (such as HCB, DDT, etc.) is reduced. How to overcome the low experimental results caused by fat? You can...

Tuesday, September 10, 2019

1. Advantages and disadvantages of commonly used extraction solvents Acetonitrile: easy to salt out; compatible with LC/MS; difficult to concentrate Acetone: not easy to salt out; easy to volatilize, concentrate Ethyl acetate: immiscible with water; less extraction of impurities;...

Saturday, September 07, 2019

There are bubbles in the mobile phase, the pump is turned off, the pressure relief valve is opened, the purge button is turned on, the degas is cleaned, the bubbles are continuously ejected from the HPLC column, and the mobile phase enters the mobile phase. No matter how many times...

Tuesday, September 03, 2019

The basic principle of SPE cartridges is that the liquid sample is made to pass through the adsorbent to retain the tested substance, and then the impurities are washed away with appropriate strength solvent, and then the tested substance is eluted with a small amount of good solvent...

Friday, August 16, 2019

NH2 HPLC columns refer to the chromatographic columns that use silica gel as matrix carrier to bond amino groups. They are usually used for the analysis of carbohydrate compounds, and the mobile phase is usually methanol, acetonitrile and buffers salt solution. - The cleaning method...

Monday, August 12, 2019

Solid phase extraction principle Solid phase extraction is a separation technique that combines selective retention, selective elution, and the like. When a complex sample solution passes through the sorbent, the sorbent selectively retains the aimed compound and a small number of...

Friday, August 09, 2019

Reversed-phase chromatography (RPC) contains any chromatographic method using a non-polar stationary phase. The word “reverse” has a historical background. In the 1970s, most liquid chromatography was performed on unmodified silica or alumina. Their surface chemistry is hydrophilic...

Thursday, August 08, 2019

Considering the comparative simplicity and maturity of the glass vial, customers rarely complain about its quality. However, the applicability of the autosamplers is actually essential to big manufacturing companies. Severely in terms of International Standard, vials of Hawach are...

Thursday, August 08, 2019

Chromatography is a separation and analysis method and the separation is the core. Therefore, HPLC columns are the heart of the chromatographic system. The requirements for the column are high efficiency, good selectivity and fast analysis speed. Generally, the column length of about...

Thursday, August 08, 2019

Most common SPE cartridges are injection syringes made of polyethylene, in which there are two plugs made of polypropylene or fiberglass, with a certain amount of chromatographic adsorbent (filler) between the two plugs. SPE cartridges without sieve plate 1. Avoid “non-specific adsorption” 2...

Saturday, August 03, 2019

SPE cartridge can be divided into three classes on the markets: silica-based cartridges, polymer-based cartridges, and adsorption-based cartridges. And here we talk about the three types of silica-based cartridges. The first type is the C18 cartridges. This kind of cartridges bond...

Thursday, August 01, 2019

As a core technology, JIUWU has become the largest ceramic membrane element producer and a world leader in cross-flow filtration. Electrodeionization (EDI) is a kind of pure water manufacturing technology which combines ion exchange technology , ion-exchange membrane technology and...

Thursday, August 01, 2019

Hawach bottle-top dispensers help to simplify the routine liquid transfer operation and are widely used in all kinds of liquid reagents – buffer solution, medium, vitamin solution, acid, alkali, salt solution or a variety of polar solution. Bottle-top dispensers can meet the needs...

Wednesday, July 31, 2019

- The Selection Principle of Silica Gel Column - Commonly, the maximum sample loading volume of a silica gel column is about 1/20 of the volume of the column's silica gel. However, as a practical matter, specific sample loading volume should be decided by each constituent's degree...

Wednesday, July 31, 2019

Solid phase extraction (SPE), developed in the 1970s, can replace the traditional liquid-liquid extraction in many fields and has been applied more and more widely in the laboratory. The common solvent of SPE Hexane, isooctane, tetrahalide carbon, trihalomethane, dihalomethane, tetrahydrofuran...

Friday, July 19, 2019

Bonded-phase chromatography is a liquid-liquid chromatography method in which a stationary phase is covalently bound to a carrier particle, which overcomes the mechanical shock in the distribution chromatography, the constant loss of the stationary phase and the gradual change of...

Friday, July 05, 2019

When the polarity of the stationary phase is greater than the polarity of the mobile phase, it can be called normal phase partition chromatography or simply normal phase chromatography. If the polarity of the stationary phase is less than the polarity of the mobile phase, it can be...

Thursday, July 04, 2019

C8 HPLC columns are used to isolate many organic compounds, which are one of the reversed phase silica gel columns. The maintenance of C8 HPLC columns requires organic solvents. Chromatographic grade methanol is recommended and different brands of chromatographic columns should be...

Thursday, July 04, 2019

The silicon hydroxyl group with strongly polar on the surface of glass sample vials will adsorb the samples. Based on such reasons, people produce hydrophobic glass surface through silylating the sample vials in order to eliminate the adsorption of the sample vials, which is widely...

Tuesday, July 02, 2019

The average sample addition recovery rate of QuEChERS method is higher than 85%, with fewer impurities interfering with the detection of the target substance, a small amount of solvent, simple and fast operation, which will be the preferred pretreatment method for routine detection...

Tuesday, July 02, 2019

In this article, we want to clarify the syringe filter. Each of the different syringe filters is applied to the specific product Which the various syringe filter is worth seeing more and what are the right steps and methods to have a try. Classification by membrane The filtration...