T/PCA 006-2024 Determination of Residues of Three Pesticides (Caffeine, Phenol, and Other Fungicides) Using Liquid Chromatography-Mass Spectrometry Methodology

Scope

Main Technical Content: 4. Method Principle: Three pesticides (hexachlorophene, dinosam, and dinex) in coffee are extracted with acetonitrile, and the extract is purified by a solid-phase extraction column. The solution is detected by liquid chromatography-mass spectrometry and quantified using external standards. 5. Reagents and Materials: Unless otherwise specified, only analytical-grade reagents are used in the analysis, and all experimental water meets the requirements of GB/T 6682 for Class I water. 5.1 Reagents 5.1.1 Acetonitrile (CH3CN, CAS No.: 75-05-8): Chromatographically pure. 5.1.2 Methanol (CH3OH, CAS No.: 67-56-1): Chromatographically pure. 5.1.3 Anhydrous sodium sulfate (Na2SO4, CAS No.: 7757-82-6): Burned at 650°C for 4 hours, stored in a desiccator, and cooled before use. 5.1.4 Ammonium acetate (CH3COONH4, CAS No.: 631-61-8): Chromatographically pure. 5.1.5 Sodium chloride (NaCl, CAS No.: 7647-14-5). 5.2 Solution Preparation 5.2.1 Acetonitrile-water solution (20+80, volume ratio): Measure 20 mL of acetonitrile and add 80 mL of water, mix well. 5.2.2 5 mmol ammonium acetate aqueous solution 5.3 Standard Samples Toxaphene (Hexachlorophene, C13H6Cl6O2, CAS: 70-30-4), dinosam (C11H14N2O5, CAS: 4097-36-3), and dinex (C12H14N2O5, CAS: 131-89-5), with purity ≥95%, or certified standard samples with a national certification and standard material certificate. 5.4 Standard Solution Preparation 5.4.1 Standard stock solution (1,000 μg/mL) 5.4.2 Mixed standard stock solution (10 μg/mL) 5.4.3 Mixed standard solution (1 μg/mL) 5.5 Materials 5.5.1 Solid-phase extraction column: 6 mL, with fillers (PSA: 225 mg; C18: 90 mg; EMR Lipid: 250 mg; Carbon S: 30 mg) or equivalent. 5.5.2 Micro-porous filter membrane (organic phase): 13 mm × 0.22 μm. 6. Instruments 6.1 Liquid chromatography-triple quadrupole mass spectrometer with electrospray ionization source (ESI). 6.2 Electronic balance: accurate to 0.001 g. 6.3 Centrifuge:

Development Information

Related Standards