Pesticide residue analysis of a dietary ingredient by gas chromatography/selected-ion monitoring mass spectrometry using neutral alumina solid-phase extraction cleanup.
A sample cleanup procedure has been developed to remove coextractives that interfere with pesticide residue analysis of a dietary ingredient (Product B), an extract consisting of Scutellaria baicalensis and Acacia catechu. Samples were extracted using 1% acetic acid in acetonitrile, followed by solid-phase extraction and analysis by capillary gas chromatography with mass spectrometry in the selective-ion monitoring mode. Neutral alumina (alumina N) was found to be the most effective sorbent to remove coextractives from Product B; other materials that were tested but failed to remove interference were graphitized carbon black/primary-secondary amine (PSA), octadecylsilane (C18), Florisil, Oasis MCX, and strong anion exchange-PSA. The method was specifically developed for Product B, which was spiked with 41 organochlorine and organophosphorus pesticides, and resulted in the recovery of 80 to 120% at U.S. Pharmacopeia limits (0.06 to 4 microg/g) for the majority of the pesticides.
Unigen Inc., Quality Control/Quality Assurance Department, 2660 Willamette Dr, NE, Lacey, WA 98516, USA.
Mijeong Lee
ML
Jeong
Michael
M
Zahn
Thao
T
Trinh
Fay A
FA
Brooke
Wenwen
W
Ma
D000045:Acacia / Q000737:chemistry; D000537:Aluminum Oxide; D019587:Dietary Supplements / Q000032:analysis / Q000633:toxicity; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D010575:Pesticides / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis / Q000633:toxicity; D031364:Scutellaria baicalensis / Q000633:toxicity; D052616:Solid Phase Extraction / Q000379:methods*
D010575:Pesticides; D010936:Plant Extracts; C499814:Scutellaria baicalensis extract; D000537:Aluminum Oxide