Quantification of Chlorate and Perchlorate in a broad range of food commodities, including baby food, nutritional formulas and ingredients by LC-MS/MS: First Action AOAC 2022.06.

BACKGROUND: Chlorate is an effective herbicide, but also a by-product of chlorinating agents used to disinfect water, one of the reasons why it is regularly found in food. Perchlorate is a ubiquitous contaminant, which is naturally occurring in the environment but also released from anthropogenic sources such as the industrial use of certain natural fertilizers. Chlorate affects the hematological system, and perchlorate the thyroid.

OBJECTIVE: Implement and validate a simple and robust analytical method for the accurate determination of chlorate and perchlorate in baby food, infant and adult formulas, and ingredients thereof, which is suited for its application in routine environments where a broad variety of food commodities must be analyzed simultaneously.

METHOD: Typically, analytes are extracted with a mixture of water, acidified methanol and dichloromethane. Optionally, for dairy products and byproducts, extraction can be performed with water, acidified methanol and EDTA, followed by two steps clean-up (freezing-out and dispersive solid phase extraction with C18 in acetonitrile). Quantitative determination is carried out by isotopic dilution liquid chromatography tandem mass spectrometry (LC-MS/MS).

RESULTS: The method was single laboratory validated in five Nestlé Quality Assurance Centers (NQACs) in a comprehensive range of representative matrices of different categories such as baby foods, infant/adult formulas and ingredients, with results generally in agreement with the acceptance criteria of the Standard Method Performance Requirements (SMPR) 2021.001 defined by AOAC INTERNATIONAL, in terms of representative matrices validated, LOQs, trueness and precision.