Patricia J. Nyman

Survey of furan in heat processed foods by headspace gas chromatography/mass spectrometry and estimated adult exposure

Furan is a suspected human carcinogen that is formed in some processed foods at low ng per g levels. Recent improvements in analytical methodology and scientific instrumentation have made it possible to accurately measure the amount of furan in a wide variety of foods. Results from analysis of more than 300 processed foods are presented. Furan was found at levels ranging from non-detectable (LOD, 0.2–0.9 ng g−1) to over 100 ng g−1. Exposure estimates for several adult food types were calculated, with brewed coffee being the major source of furan in the adult diet (0.15 µg kg−1 body weight day−1). Estimates of mean exposure to furan for different subpopulations were calculated. For consumers 2 years and older, the intake is estimated to be about 0.2 µg kg−1 body weight day−1.

Comparison of two clean‐up methodologies for the gas chromatographic/mass spectrometric determination of low nanogram/gram levels of polynuclear aromatic hydrocarbons in seafood

The March 1989 oil spill in Alaska prompted the Food and Drug Administration (FDA) to conduct a thorough investigation of clean-up methodologies aimed at determining low ng/g (ppb) levels of polynuclear aromatic hydrocarbons (PAHs) in seafood. The clean-ups from a modified FDA method and a National Marine Fisheries Service (NMFS) method were evaluated on the basis of the determination of 18 PAHs at levels ranging from 1 to 5 ppb by gas chromatography/mass spectrometry. In the modified FDA method, seafood extracts were purified by a liquid-liquid partition followed by a three-step elution through silica, alumina, and C18 solid-phase extraction cartridges. In the NMFS method, seafood extracts were purified by column chromatography through a deactivated silica gel/alumina column and a gel permeation high performance liquid chromatography column. Both methods quantitated 18 PAHs at levels ranging from 1 to 5 ppb. With the exception of naphthalene, average recoveries based on internal deuterated standards ranged from 73 to 144% for the modified FDA method and 63 to 106% for the NMFS method.

Screening method for the gas chromatographic/mass spectrometric determination of microgram/litre levels of bromate in bottled water

Bromate can be formed as a by-product of ozone treatment that is sometimes used for the disinfection of municipal water supplies and bottled waters. The US Environmental Protection Agency has proposed a maximum contaminant level (MCL) of 10 micrograms/l for bromate in public drinking water. Should the proposed MCL for bromate become final, it may then be considered for adoption as a bottled water quality standard by the US Food and Drug Administration. This paper reports the development of a gas chromatographic/ mass spectrometric (GC/MS) method for the determination of parts-per-billion (microgram/l) levels of bromate (BrO3-) in bottled water. The GC/MS method was validated by using distilled and deionized Milli-Q water; detection limits, quantitation limits, and recoveries were determined and identities were confirmed by MS on the basis of analyses of test portions fortified with BrO3- at 0.8, 3.8, 7.7, 15, and 46 micrograms/l. The method also was evaluated on the basis of recoveries determined for two commercial brands of bottled water fortified with BrO3- at 3.8 and 7.7 micrograms/l and two commercial brands fortified at 0.8, 3.8, and 7.7 micrograms/l. For the Milli-Q water, recoveries ranged from 100 to 121%; for the fortified commercial products, recoveries ranged from 87 to 115%. The limits of detection and quantitation were determined to be 0.4 and 0.7 microgram/l, respectively. Several commercial brands of bottled water were analysed, and BrO3- was found in these products at levels ranging from none to 38 micrograms/l.

Ethyl carbamate levels resulting from azodicarbonamide use in bread

Azodicarbonamide (ADA), a dough conditioner, is an additive approved in the US up to a maximum of 45 mg/kg in flour. The addition of 45 mg/kg of ADA was investigated and found to increase the ethyl carbamate (EC) content of commercially prepared breads by 1-3 micrograms/kg. A similar increase in EC was observed in breads baked in the laboratory with a bread machine. The increase in EC levels appears to depend on a variety of factors, most notably the concentration of ADA added and the time of fermentation. The addition of 20 mg/kg ADA caused only a slight increase, if any, in commercial products but a 2.3 micrograms/kg increase of EC in breads baked with a bread machine. When 100 mg/kg of ascorbic acid was added along with ADA, smaller EC increases were observed. Addition of urea was also found to enhance the EC content of the bread. Toasting, which was previously shown to increase EC levels, caused even larger increases when ADA or urea had been added.

Simultaneous Analysis of 3-MCPD and 1,3-DCP in Asian Style Sauces Using QuEChERS Extraction and Gas Chromatography–Triple Quadrupole Mass Spectrometry

Acid hydrolyzed vegetable protein (aHVP) is used for flavoring a wide variety of foods and also in the production of nonfermented soy sauce. During the production of aHVP, chloropropanols including 3-monochloropropane-1,2-diol (3-MCPD) and 1,3 dichloropropane-2-ol (1,3-DCP) can be formed through the reaction of the hydrochloric acid catalyst and residual fat and the reaction of 3-MCPD with acetic acid, respectively. 3-MCPD is a carcinogen, and 1,3-DCP has been classified as a genotoxic carcinogen. The European Union (EU) has set a maximum concentration of 0.02 mg/kg of 3-MCPD in aHVP, and the Food and Drug Administration (FDA) set a guidance limit of 1 mg/kg of 3-MCPD in aHVP. 1,3-DCP is not an approved food additive, and the Joint FAO/WHO Expert Committee on Food Additives (JEFCA) has set a limit at 0.005 mg/kg, which is close to the estimated method detection limit. Currently there are few analytical methods for the simultaneous determination of 3-MCPD and 1,3-DCP without derivatization due to differences in their physical chemical properties and reactivity. A new method was developed using QuEChERS (quick, easy, cheap, effective, rugged, and safe) with direct analysis of the extract without derivatization using gas chromatography-triple quadrupole mass spectrometry (GC-QQQ). Additionally, a market sampling of 60 soy sauce samples was performed in 2015 to determine if concentrations have changed since the FDA limit was set in 2008. The sampling results were compared between the new QuEChERS method and a method using phenylboronic acid (PBA) as a derivatizing agent for 3-MCPD analysis. The concentrations of 3-MCPD detected in soy sauce samples collected in 2015 (<MDL to 0.53 mg/kg) compared to 2003 (<MDL to 876 mg/kg) indicate that manufacturing controls currently in use during aHVP production have been effective at reducing 3-MCPD below current regulatory limits.