Profenofos CRM may also be used as given below: Evaluation of 250 pesticide residues extracted by QuEChERS method from 103 processed fruit samples using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS. Gas chromatography-tandem mass spectrometry (GC-MS/MS) based analysis of 213 pesticide residues in soybean after their extraction by QuEChERS procedure. Detection of 252 pesticides extracted from surface water samples by solid-phase extraction (SPE) using liquid chromatography quadrupole-orbitrap high-resolution tandem mass spectrometry. Multi-residue analysis of 160 multiclass pesticides using ethyl acetate (EtAC)/n. hexane mixture for extraction from chamomile thyme and marjoram samples and their analysis by gas chromatography-tandem mass spectrometry (GC-MS/MS). Simultaneous determination of 34 pesticides in various environmental water samples by dispersive liquid-liquid microextraction (DLLME) technique in combination with gas chromatography-mass spectrometry(GC-MS/MS). Quantitation of 40 multi-class insecticides and fungicides in 81 apple samples by using gas- and liquid- chromatography-mass following a QuEChERS-based extraction.