In the actual detection process, the sample matrix may be different from the standard solution, so it is necessary to digest and extract the sample before the content determination. If the sample pretreatment is not complete, the interfering substances in the matrix are not completely eliminated, or the target substance is lost in the pretreatment process, the determination results may be inaccurate (in this case, it is usually possible to select a matrix similar to the capacity verification sample and carry out addition and recovery experiments at the same time).
Sample pretreatment includes organic treatment and inorganic treatment.
Inorganic pretreatment equipment: oven, acid tank, (wet and dry sample) grinder, temperature-controlled shaker, ultrasonic cleaner, desktop centrifuge, electric heating plate, microwave digester, etc.
Equipment for organic pretreatment: ultrasonic instrument, shaking table, (rapid solvent, rapid Soxhlet, microwave) extractor, solid phase extractor, (fully automatic or semi-automatic, with or without concentration and constant volume) gel permeation chromatography GPC, rotary evaporator, nitrogen purging thickener, etc.