Welch products introduction

SPE cartridge

Solid Phase Extraction (SPE) is a widely used and increasingly popular sample pretreatment technology. It’s commonly used to process liquid samples, extract, concentrate and purify semi-volatile and non-volatile compounds. It can also be used for solid samples, but the solid samples must be processed into liquid first. At present, it is mainly used in the field of food safety, such as the residue analysis of various antibiotics and antibacterial drugs in various kinds of food, analysis of pesticide residues in agricultural products, analysis of legal and illegal additives in various kinds of food, etc. In the field of drug research, it is widely used in pharmacokinetic analysis, and traditional medicine analysis.

In the field of environmental protection, it is applied to analyze environmental polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and various pesticides. Organic matter analysis of drinking water, groundwater and sewage. Relying on core technology and strong new product development capability in chromatographic packing materials manufacturing, Welch has launched Welchrom series of SPE products which can greatly meet your experimental needs.

    Welchrom Polymeric SPE

    Welchrom polymer based packing materials have overcome the shortcomings of traditional silica matrix packing materials, and the use proportion of SPE has been increasing gradually.
    Welchrom SPE polymer matrix has the following advantages over silica matrix:

    1. The pH range is wide (0-14), and can be used with most organic solvents.
    2. There is no active hydroxyl group on the polymer surface, which eliminates the influence of secondary adsorption caused by insufficient recovery rate of basic compound.
    3. Polymer matrix has large adsorption capacity and higher recovery rate for most organic compounds, organic compounds are prone to be quantitatively eluted after adsorption, so the analysis results have great reproducibility.
    4. High recovery rate and high adsorption capacity reduce the detection limit and the amount of polymer adsorbent needed.
    5. Some expensive extracts will not be contaminated by the hydrolysis of the bonded phase. Spherical particles, narrow particle sizedistribution, to ensure the reproducibility of the results.
    6. High anti-interference stability: if Welchrom polymer based SPE column accidentally get dried during sample preparation, it can be rewetted and retain its properties without risking loss of analytes and affecting the reproducibility of the results.
    Currently, BRP, P-SCX, P-WCX, P-WAX, P-SAX and PS/DVB are available for your sample processing.

     

    Mixed ion-exchange reversed phase adsorbents can be obtained by different ionic groups bonded the benzene ring of Welchrom® BRP.
    They are as follows:

    1. P-SCX: a mixed-mode strong cation exchange reversed-phase adsorbent, obtained by BRP adsorbent bonded sulfonic acid groups
    2. P-SAX: a mixed mode strong anion exchange reversed-phase adsorbent, obtained by BRP adsorbent bonded quaternary ammonium
      groups. It has both anion-exchange and inverse-phase retention modes and is suitable for carboxylic acid compounds with pKa between
      2-8.
    3. P-WCX: a mixed mode weak cation exchange reversed-phase adsorbent, obtained by BRP adsorbent bonded carboxyl groups, with both weak cation exchange and reversed-phase retention modes, suitable for strongly basic compounds whose pKa of conjugated acids is greater than 10, such as compounds containing quaternary ammonium groups.
    4. P-WAX: a mixed mode weak anion exchange reversed-phase adsorbent, obtained by BRP adsorbent bonded piperazine groups, with both weak cation exchange and reversed-phase retention modes, suitable for strongly acidic compounds whose pKa is less than 1, such as compounds containing sulfonic acid and phosphoric acid groups.

    Welchrom Silica Based SPE

    Welchrom silica SPE products select amorphous silica gel of high quality and high purity with an average particle size of 45 μm, an average pore diameter of 60 Å, Pore volume of 0.80 cm3/g and Surface area of 480 m2/g. This kind of silica gel is an ideal choice for extraction with moderate resistance and flow rate. In addition, Welch uses unique surface treatment technology when bonding silicone.
    Further, the bonding phase also adopts a more stable three-way bonding mode, which ensures the constant extraction recovery rate of the analytes. At present, the most commonly used adsorbent in SPE is still silica gel or bonded silica gel with pH range of 2-7.5. There are various kinds of silica based adsorbents can be selected.
    In Welchrom SPE products, Silica matrices include C18E(end-capped), C18(unend-capped), C8, Phenyl, CN, NH2, PSA, SCX, SAX, WAX, PRS, Silica, Diol.
    General properties of silica-based adsorbent:

    1. Functional groups bonded on the surface of silica gel play a major role in the retention of target compounds; Based on the different types of bonding functional groups, the retention mechanism of adsorbent on the target compound includes reversed-phase retention, normal phase retention and ion exchange retention.
    2. The silica gel bonded adsorbent is stable in the pH range of 2-7.5.
    3. The silica gel bonded adsorbent is rigid, neither shrinks nor expands when the solvent is transformed, and it can quickly reach a balance in the new solvent.
    4. The silica gel bonded adsorbent substrate is 40-63 μm spherical silica gel, with uniform particle size and smooth surface, even under the condition of no pressure solvent, it can pass through the adsorbent; The silica gel bonded adsorbent has a characteristic pore diameter of about 60 Å and is suitable for compounds with molecular weight less than 15,000. In the synthesis of reversed-phase adsorbent, they are all end-capped, while normal phase adsorbents and ion exchange adsorbents are unend-capped.

    Welchrom Inorganic SPE

    Welchrom Inorganic SPE is commonly used as a normal phase polarity adsorbent, with different polarity and surface pH, and different applications. However, it is generally used for sample purification before analysis, especially for the purification of organic extract of complex samples. Florisil PR adsorbent, for example, is often used to purify organic solvent extracts of plant and animal tissue samples, most commonly for pesticide residue analysis. Such adsorbents are also used in the pretreatment of samples for the detection and analysis of Sudan red and malachite green in food.
    Welchrom Inorganic SPE matrix inorganic adsorbent has good purification effect, high and constant recovery, good reproducibility after strictly controlled activation treatment.

    Welchrom Mixed Mode SPE

    Welchrom  Mixed Mode SPE adsorbent is a mixture of stationary phases with two modes of action, using a variety of interfacial effects to separate and purify the analytical components. Extraction of alkaline drugs from the biological matrix and analysis of agricultural residues in the biological matrices. As there are many interferences in the biological matrix which are difficult to be washed or removed, such mixed-mode adsorbents are often required.

    Welchrom Special SPE

    Welchrom special SPE column adsorbents include benzopyrene column, Sudan red column, plasticiser column, tea column and Chinese herbal medicine column.

    Welchrom Immunoaffinity Column

    Welchrom Immunoaffinity Column is used to separate and purify mycotoxins from samples based on specific reactions between antigens and antibodies. Antibodies in the immunoaffinity column suspend in the gel by covalent bonding and specifically adsorb the mycotoxin in the sample. If the sample being tested contains the mycotoxin, the toxin will be captured and bound by the antibody when the sample passes through the immunoaffinity column.
    All other substances will be washed out of the immunoaffinity column. Methanol is used as an eluent to elute mycosins from the antibodies.

    Welchrom Immunoaffinity Column has features as follows

    1. Select monoclonal antibodies with high specificity and affinity to ensure obtaining high-purity samples.
    2. Has large capacity and high antibody content, which increases the sample adsorption capacity and improves the purification efficiency.
    3. Large volume samples are allowed to be purified through column, which has excellent concentration effect on low concentration samples, thus effectively improving the detection of various methods.
    4. Passed a large number of scientific experiments, with good stability and reliability, while the sample recovery rate can reach 90%-110%.
    5. The product has strong versatility and is suitable for a variety of buffer systems without complex and toxic reagents.
    6. Simple and fast operation, only 10-15 minutes for a single sample. Strong applicability, no need for specific experimental environment.
    7. The purified samples are suitable for ELISA, HPLC, fluorescence spectrophotometry, etc.
    8. Conform to national standard method.

    Application

    Detection of mycotoxin in grain, peanut, grain oil, alcohol, feed, Chinese medicinal materials, flavoring and dairy products

    Doprah IC Pretreatment Column

    In the process of ion chromatography, impurities such as metal ions or organic compounds are often found in the samples. On the one hand, the presence of these impurities will interfere with the detection of target ions, and on the other hand, it will cause pollution of ion chromatography column packing, reducing the separation performance and life of the column. The pretreatment column of ion chromatography is developed based on the principle of solid phase extraction, using high purity filler, using the principle of reverse adsorption and ion exchange, can effectively remove impurities such as impurity ion and organic matter in the sample, to avoid the influence of impurities on the pollution of ion chromatography column and its separation performance.

    Ion chromatography pretreatment column: IC-H, IC-AG, IC-AG /H, IC-BA, IC-NA, IC-RP, IC-C18, IC-AG /Na, IC-BA /Ag/H

    Purification mode

    1. Impurity adsorption mode -- purification: the interfering component is combined with fixation, and the analyte is not retained by the column but directly passed through.
    2. Target adsorption mode -- enrichment + matrix elimination: the analyte is combined with the fixed phase, and the interfering component is not retained by the column but directly passed through. Then appropriate eluent is used to extract the analyte.

    Advantages

    • Exchange capacity: 2.7-2.9 meg, 1.3 times that of common products on the market
    • High column packing capacity, more thorough removal of impurities, can be used for multiple times depending on the specific conditions of the sample
    • Column body adopts unique combination mode, which can resist high pressure and prevent collapse or leakage
    • Low concentration of ion residue in IC column to ensure the accuracy of detection