Baseline levels of melamine in food items sold in Canada. II. Egg, soy, vegetable, fish and shrimp products.

A variety of egg-containing, soy-based, fish, shrimp and vegetable products sold in Canada were analysed for melamine (MEL) using a sensitive solid-phase extraction LC-MS/MS analytical method. MEL was detected above the method quantification limit of 0.004 mg/kg in 98 of the 378 samples analysed.

Baseline levels of melamine in food items sold in Canada. I. Dairy products and soy-based dairy replacement products.

A variety of dairy and soy-based dairy replacement products (n = 246) purchased from Canadian retail outlets were analysed for baseline levels of melamine (MEL) using a sensitive LC-MS/MS method (method quantification limit = 4 µg/kg). MEL was infrequently detected; only 14% of the items analysed contained quantifiable levels of MEL. The concentrations observed, aside from one recalled sample of candy, ranged from 0.

Methods for the analysis of melamine and related compounds in foods: a review.

In recent years, two adulteration incidents concerning the addition of melamine (MEL) and related compounds to dairy products and vegetable proteins have occurred in China. These episodes prompted numerous governmental and private laboratories to develop or implement methods for the analysis of a wide variety of food products for MEL and related compounds, including cyanuric acid, ammeline, and ammelide. Methods have been developed for both screening and quantitation purposes; procedures used in the methods range from sensitive hyphenated chromatographic-mass spectrometric techniques to immunoselective assays.

Dietary exposure of Canadians to perfluorinated carboxylates and perfluorooctane sulfonate via consumption of meat, fish, fast foods, and food items prepared in their packaging.

Human exposure to perfluorinated compounds is a worldwide phenomenon; however, routes of human exposure to these compounds have not been well-characterized. Fifty-four solid food composite samples collected as part of the Canadian Total Diet Study (TDS) were analyzed for perfluorocarboxylates and perfluorooctanesulfonate (PFOS) using a methanol extraction liquid chromatography tandem mass spectrometry method. Foods analyzed included fish and seafood, meat, poultry, frozen entrées, fast food, and microwave popcorn collected from 1992 to 2004 and prepared as for consumption.

Concentrations of perfluorooctanesulfonamides in Canadian total diet study composite food samples collected between 1992 and 2004.

Canadian Total Diet Study composite samples collected from 1992 to 2004 (n = 151) were analyzed for a series of perfluorooctanesulfonamides that are likely breakdown products or manufacturing residuals associated with perfluorooctylsulfonyl phosphate esters. These esters have been incorporated into coatings for paper and paperboard used in food packaging. N-Ethylperfluorooctanesulfonamide (N-EtPFOSA), perfluorooctanesulfonamide, N,N-diethylperfluorooctanesulfonamide, N-methylperfluorooctanesulfonamide, and N,N-dimethylperfluorooctanesulfonamide were extracted using solvent extraction and quantified by gas chromatography-mass spectrometry.

Quantitative determination of paralytic shellfish poisoning toxins in shellfish using prechromatographic oxidation and liquid chromatography with fluorescence detection: collaborative study.

A collaborative study was conducted for the determination of paralytic shellfish poisoning (PSP) toxins in shellfish. The method used liquid chromatography with fluorescence detection after prechromatographic oxidation of the toxins with hydrogen peroxide and periodate. The PSP toxins studied were saxitoxin (STX), neosaxitoxin (NEO), gonyautoxins 2 and 3 (GTX2,3; together), gonyautoxins 1 and 4 (GTX1,4; together), decarbamoyl saxitoxin (dcSTX), B-1 (GTX5), C-1 and C-2 (C1,2; together), and C-3 and C-4 (C3,4; together).

Development and characterization of a solvent extraction-gas chromatographic/mass spectrometric method for the analysis of perfluorooctanesulfonamide compounds in solid matrices.

A method utilizing solvent extraction and analysis by gas chromatography-positive chemical ionization mass spectrometry (SE-GC-PCIMS) was developed for the analysis of three neutral hydrophobic perfluorooctanesulfonamide compounds [perfluorooctanesulfonamide (PFOSA), N-ethyl perfluorooctanesulfonamide (N-EtPFOSA), and N,N-diethyl perfluorooctanesulfonamide (N,N-Et2PFOSA)]. These compounds are suspected metabolic precursors of perfluorooctane sulfonate. The SE-GC-PCI-MS method was used to analyze all three perfluorooctanesulfonamides in fast food, fish, and Arctic marine mammal liver samples.

Polybrominated diphenyl ethers in retail fish and shellfish samples purchased from Canadian markets.

Fish and shellfish retail samples (n = 122) were purchased from three Canadian cities in the winter of 2002 and analyzed for a total of 18 polybrominated diphenyl ether (PBDE) congeners. The samples (salmon, trout, tilapia, Arctic char, mussels, oysters, shrimp, and crab) represented the range of fish and shellfish commercially available to Canadian consumers at the time of purchase. Trout and salmon (geometric mean SigmaPBDE = 1600 and 1500 pg/g, wet weight, respectively) were found to contain significantly higher amounts of PBDEs than the mussel, tilapia, and shrimp groups (geometric mean SigmaPBDE = 260, 180, and 48 pg/g, wet weight, respectively).

Quantitative determination of paralytic shellfish poisoning toxins in shellfish using prechromatographic oxidation and liquid chromatography with fluorescence detection: interlaboratory study.

An interlaboratory study was conducted for the determination of paralytic shellfish poisoning (PSP) toxins in shellfish. The method used liquid chromatography with fluorescence detection after prechromatographic oxidation of the toxins with hydrogen peroxide and periodate. The PSP toxins studied were saxitoxin (STX), neosaxitoxin (NEO), gonyautoxins 2 and 3 (GTX2,3 together), gonyautoxins 1 and 4 (GTX1,4 together), decarbamoyl saxitoxin (dcSTX), B-1 (GTX5), C-1 and C-2 (C1,2 together), and C-3 and C-4 (C3,4 together).

Dietary exposure to a group of naturally produced organohalogens (halogenated dimethyl bipyrroles) via consumption of fish and seafood.

Concentrations of four naturally produced halogenated dimethyl bipyrroles (HDBPs) were quantitated in marine fish (n = 10), freshwater fish (n = 10), canned fish (n = 10), and shrimp composites (n = 10) collected from 1992 to 2002 for the Canadian Total Diet Study. Canned fish composites composed of epipelagic higher trophic level species contained the highest concentration of HDBPs (SigmaHDBP geometric mean +/- standard error = 880 +/- 690 pg/g of wet weight, n = 10), which was significantly higher than that found in the other three composites. There were no significant temporal trends of HDBP concentrations observed for any of the four composites.