Open AccessQuantification of Nonpersistent Pesticides in Small Volumes of Human Breast Milk with Ultrahigh Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry
Author(s) -
Theresa L. Pedersen,
Jennifer T. Smilowitz,
Carl K. Winter,
Shiva Emami,
Rebecca J. Schmidt,
Deborah H. Bennett,
Irva HertzPicciotto,
Ameer Y. Taha
Publication year - 2021
Publication title -
journal of agricultural and food chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.203
H-Index - 297
eISSN - 1520-5118
pISSN - 0021-8561
DOI - 10.1021/acs.jafc.0c05950
Subject(s) - chromatography , chemistry , extraction (chemistry) , dichloromethane , breast milk , tandem mass spectrometry , solid phase extraction , sample preparation , pesticide , liquid chromatography–mass spectrometry , analyte , reproducibility , solvent , pesticide residue , mass spectrometry , biochemistry , organic chemistry , agronomy , biology
Existing methods for the analysis of pesticides in human breast milk involve multiple extraction steps requiring large sample and solvent volumes, which can be a major obstacle in large epidemiologic studies. Here, we developed a simple, low-volume method for extracting organophosphates, pyrethroids, carbamates, atrazine, and imidacloprid from 100 to 200 μL of human breast milk. Multiple extraction protocols were tested including microwave-assisted acid/base digestion and double-solvent extraction with 2 or 20 mL of 2:1 (v/v) dichloromethane/hexane, with or without subsequent solid-phase extraction (SPE) cleanup. Samples were analyzed by liquid chromatography tandem mass spectrometry. Analyte recoveries and reproducibility were highest when 100-200 μL of milk were extracted with 2 mL of dichloromethane/hexane without subsequent SPE steps. Analysis of 79 breast milk samples using this method revealed the presence of carbamates, organophosphates, pyrethroids, and imidacloprid at detection frequencies of 79-96, 53-90, 1-7, and 61%, respectively. This study demonstrates the feasibility of a simple low-volume extraction method for measuring pesticides in human breast milk.