title: Determination of perchlorate in infant formula by isotope dilution ion chromatography/tandem mass spectrometry.
abstract: A sensitive and selective isotope dilution ion chromatography/tandem mass spectrometry (ID IC-MS/MS) method was developed and validated for the determination of perchlorate in infant formula. The perchlorate was extracted from infant formula by using 20 ml of methanol and 5 ml of 1% acetic acid. All samples were spiked with (18)O(4) isotope-labelled perchlorate internal standard prior to extraction. After purification on a graphitised carbon solid-phase extraction column, the extracts were injected into an ion chromatography system equipped with an Ionpac AS20 column for separation of perchlorate from other anions. The presence of perchlorate in samples was quantified by isotope dilution mass spectrometry. Analysis of both perchlorate and its isotope-labelled internal standard was carried out on a Waters Quattro Ultima triple quadrupole mass spectrometer operating in a multiple reaction monitoring (MRM) negative ionisation mode. The method was validated for linearity and range, accuracy, precision, sensitivity, and matrix effects. The limit of quantification (LOQ) was 0.4 µg l(-1) for liquid infant formula and 0.95 µg kg(-1) for powdered infant formula. The recovery ranged from 94% to 110% with an average of 98%. This method was used to analyse 39 infant formula, and perchlorate concentrations ranging from <LOQ to 13.5 µg l(-1).
authors.affiliation: Food Research Division, Banting Research Center 2203D, Health Canada, Ottawa, Ontario, Canada.
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: B P-Y
authors.initials: BP
authors.lastname: Lau
authors.forename: B
authors.initials: B
authors.lastname: Tague
authors.forename: M
authors.initials: M
authors.lastname: Sparling
authors.forename: D
authors.initials: D
authors.lastname: Forsyth
mesh_terms: D013956:Antithyroid Agents / Q000032:analysis* / Q000302:isolation & purification; D002170:Canada; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D052244:Endocrine Disruptors / Q000032:analysis* / Q000302:isolation & purification; D004785:Environmental Pollutants / Q000032:analysis* / Q000302:isolation & purification; D005506:Food Contamination / Q000706:statistics & numerical data; D005513:Food Inspection / Q000379:methods*; D006801:Humans; D007201:Indicator Dilution Techniques; D007223:Infant; D041943:Infant Formula / Q000737:chemistry*; D057230:Limit of Detection; D010103:Oxygen Isotopes; D010472:Perchlorates / Q000032:analysis* / Q000302:isolation & purification; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D013956:Antithyroid Agents; D052244:Endocrine Disruptors; D004785:Environmental Pollutants; D010103:Oxygen Isotopes; D010472:Perchlorates; C494474:perchlorate