Soil—Determination of Dicofol—Gas Chromatography-Mass Spectrometry

This standard applies to the determination of dicofol in soil. It specifies gas chromatography-mass spectrometry procedures for sample collection and preservation, preparation, pressurized fluid extraction, cleanup, concentration, instrumental analysis, result calculation, and quality assurance and quality control. Soil samples shall be sealed, protected from light, refrigerated below 4°C, and stored for no more than 10 days. Samples are freeze-dried or dehydrated with a desiccant, extracted with a hexane-acetone mixture, and cleaned up using a magnesium silicate solid-phase extraction cartridge. Quantification is performed by the internal standard method, while identification is based on retention time, fragment-ion mass-to-charge ratios, and ion abundances; requirements for calibration, blank tests, precision, and accuracy are also specified.