Recent developments in the estimation of trace toxic substances in food

An evaluation on the extraction capability of anion exchange membranes for high-precision sulfur isotope measurement by multiple-collector inductively coupled plasma mass spectrometry

Anion exchange membranes (AEMs) are adept at extracting sulfate for sulfur isotope analyses by multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) from natural samples typically with low sulfate concentrations.

Confirmation of trace level residues in the food supply

With the recent proliferation of mass spectrometric methods available for the identification and confirmation of various compounds in different environmental matrices, it is timely to address the criteria desirable in a regulatory sample case. The emphasis of this review is on the experimental process of confirmation at concentration levels in the range of low parts per million (ppm) to parts per trillion (ppt). At such levels, various data manipulations or alternate choices of approaching the analytical problem of confirmation must be employed to ensure an acceptable result. The problems experienced when dealing with nanogram levels in analysis are much more complex than when recording a mass spectrum of an ample supply of a reference standard. This review reflects an interpretation of the developing status of confirmation since there does not yet exist "accepted criteria".

Extraction and clean-up of contaminants and toxicants from food for mass spectrometric analysis--a literature review

This report presents a review of the literature on the extraction and clean-up procedures used prior to the analysis, by mass spectrometry, of organic contaminants and toxicants in foods and food-related materials. It includes a brief description of the uses of a mass spectrometer and shows how the mode of operation of the machine can influence the amount of clean-up necessary before a sample is presented for analysis. The review covers a variety of contaminants of different compound types in a wide range of foods and not only discusses sample preparation techniques that have been used for contaminant analysis by mass spectrometry but also considers some that could be used. The most commonly used techniques involve solvent extraction followed by a clean-up using liquid-liquid partition or column chromatography or both, although a number of newer methods being evolved are moving towards the ideal of a single-step extraction and clean-up process.

Application of mass spectrometry in the regulatory analysis of pesticides and industrial chemicals in food and feed commodities

During regulatory analysis of pesticides and industrial chemicals, compounds are frequently encountered which cannot be readily identified by gas chromatography alone on two or more stationary phases. Such incurred unknown analytical responses are examined by gas chromatography mass spectrometry, particularly if they have been shown to contain P, S, N or halogen via specific gas chromatography detectors. Seven case histories are presented to illustrate the analytical approach adopted to structurally elucidate such compounds at the ppm level. These examples demonstrate the potential complementary combination provided by low resolution electron impact and chemical ionization mass spectrometry in structural determinations.