Frequently asked questions about QuEChERS products in experiments(part 2)
Q. If the pesticide is volatile, then when we use this kind of pesticide, will it be evaporated into the air at a slightly higher temperature?
A: Volatileness is not strong enough to volatilize at room temperature. It is only because of the exothermic reaction of anhydrous magnesium sulfate with water, which can cause loss of these pesticides.
Q. Previously, activated carbon was used to remove the pigment, and the sample had a large loss. Because in normal experiments, it is often necessary to deal with pigments (generally to remove pigments), can I use it as a filler to make pillars or SPE cartridges to remove pigments? Is it still selective for water-soluble and fat-soluble pigments?
A: Hawach can provide finished products of graphitized carbon black SPE columns.
Q. Freezing and degreasing: The extract or the purified sample is placed in the refrigerator for more than 1 hour (or frozen overnight). Adsorption of reversed-phase adsorbent: C18E or C8 adsorbent is added to the extract to remove fat. Can the above two methods of degreasing be used together or separately? What are the advantages and disadvantages of each?
A: The decreasing effect of the frozen degreasing and C18E adsorbents is equivalent, but it takes longer to use the degreasing and freezing, which is fatal to increase the sample throughput. At the same time, other non-polar interferences can be removed by using C18E adsorbent. Of course, the cost of using C18E degreasing will be a little higher.