Analysis of perchlorate in foods and beverages by ion chromatography coupled with tandem mass spectrometry (IC-ESI-MS/MS) [An article from: Analytica Chimica Acta]

This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
A new IC-ESI-MS/MS method, with simple sample preparation procedure, has been developed for quantification and confirmation of perchlorate (ClO"4^-) anions in water, fresh and canned food, wine and beer samples at low part-per-trillion (ngl^-^1) levels. To the best of our knowledge, this is the first time an analytical method is used for determination of perchlorate in wine and beer samples. The IC-ESI-MS/MS instrumentation consisted of an ICS-2500 ion chromatography (IC) system coupled to either an API 2000(TM) or an API 3200(TM) mass spectrometer. The IC-ESI-MS/MS system was optimized to monitor two pairs of precursor and fragment ion transitions, i.e., multiple reaction monitoring (MRM). All samples had oxygen-18 isotope labeled perchlorate internal standard (ISTD) added prior to extraction. Chlorine isotope ratio (^3^5Cl/^3^7Cl) was used as a confirmation tool. The transition of ^3^5Cl^1^6O"4^- (m/z 98.9) into ^3^5Cl^1^6O"3^- (m/z 82.9) was monitored for quantifying the main analyte; the transition of ^3^7Cl^1^6O"4^- (m/z 100.9) into ^3^7Cl^1^6O"3^- (m/z 84.9) was monitored for examining a proper isotopic abundance ratio of ^3^5Cl/^3^7Cl; and the transition of ^3^5Cl^1^8O"4^- (m/z 107.0) into ^3^5Cl^1^8O"3^- (m/z 89.0) was monitored for quantifying the internal standard. The minimum detection limit (MDL) for this method in de-ionized water is 5ngl^-^1 (ppt) using the API 2000(TM) mass spectrometer and 0.5ngl^-^1 using the API 3200(TM) mass spectrometer. Over 350 food and beverage samples were analyzed mostly in triplicate. Except for four, all samples were found to contain measurable amounts of perchlorate. The levels found ranged from 5ngl^-^1 to 463.5+/-6.36@mgkg^-^1 using MRM 98.9->82.9 and 100@ml injection.