Sources of low concentrations of bisphenol A in canned beverage products.

Although migration from can coatings is likely the source of bisphenol A (BPA) for the canned soft drink products with relatively high BPA concentrations, questions have been raised concerning the exact sources of BPA for those canned soft drink products with low BPA concentrations. Information is also needed for BPA concentrations in canned beer products to conduct proper exposure assessment for BPA under the Government of Canada's Chemicals Management Plan. In this work, 22 soft drink samples and 16 beer samples in both cans and plastic and/or glass bottles were analyzed for BPA. BPA was not detected in any of the soft drink samples in either plastic or glass bottles except for one product with a BPA concentration (0.018 microg/liter) close to the limit of quantification (0.015 microg/liter). BPA was detected in all of the corresponding soft drink products in cans, indicating that migration from can coatings is the likely source for BPA in canned products. Because considerable interference with ions m/z 213 and m/z 228 from sample matrices was observed for all beer samples, BPA concentrations in beer samples were measured using the ion m/z 270 instead. BPA was detected in only one of the seven beer products in glass bottles (0.054 microg/liter) but was detected in all corresponding beer samples in cans at low concentrations ranging from 0.081 to 0.54 microg/liter, indicating that migration from can coatings is likely the source of BPA in canned beer products.

Background bisphenol A in experimental materials and its implication to low-dose in vitro study.

In vitro low-dose studies are important to understand the mechanisms of bisphenol A (BPA) action. BPA doses used in current in vitro studies varied considerably, and doses as low as 10(-15)M have been reported. The actual doses of BPA used in the in vitro low-dose studies were rarely checked analytically, and the background BPA levels in experimental materials, which will determine the lowest BPA dose to be used, should be investigated or considered. In this study, the background BPA levels in various materials typically used in in vitro low-dose studies for BPA were investigated. Background BPA levels from the use of disposable pipettes and pipette tips were low (<0.20 ng mL(-1) or 0.88 nM). BPA was also detected in several commercial buffer solutions at levels close to the method limit of quantification (LOQ) (0.02 ng mL(-1); 0.088 nM). However, BPA was detected in all cell culture media obtained from various sources at levels ranging from 0.080 to 4.26 ng mL(-1) (or 0.35 to 19 nM) with an average of 0.83 ng mL(-1) (3.5 nM). We suggest that culture media used for low-dose BPA studies should be analysed for background BPA levels prior to use, and the medium with the lowest BPA levels should be used.

Bisphenol a in canned food products from canadian markets.

A method based on solid phase extraction followed by derivatization and gas chromatography-mass spectrometry analysis was validated for the determination of bisphenol A (BPA) in canned food products. This method was used to analyze 78 canned food products for BPA. Concentrations of BPA in canned food products differed considerably among food types, but all were below the specific migration limit of 0.6 mg/kg set by the European Commission Directive for BPA in food or food simulants. Canned tuna products had the highest BPA concentrations in general, with mean and maximum values of 137 and 534 ng/g, respectively. BPA concentrations in the condensed soup products were considerably higher than those in the ready-to-serve soup products, with mean and maximum values of 105 and 189 ng/g, respectively, for the condensed soups and 15 and 34 ng/g, respectively, for the ready-to-serve soups. BPA concentrations in canned vegetable products were relatively low; about 60% of the products had BPA concentrations of less than 10 ng/g. Canned tomato paste products had lower BPA concentrations than did canned pure tomato products. The mean and maximum BPA concentrations were 1.1 and 2.1 ng/g, respectively, for tomato paste products and 9.3 and 23 ng/g, respectively, for the pure tomato products.

Migration of bisphenol A from can coatings to liquid infant formula during storage at room temperature.

Information on migration of bisphenol A (BPA) from can coatings to foods during storage at room temperature is very limited, and the conclusions from the available studies are not always consistent. To investigate the effect of storage time on BPA migration from can coatings to liquid infant formula at room temperature, samples of 21 canned liquid infant formula products from different cans but the same lot as those analyzed for BPA previously were analyzed for BPA again after storage at room temperature for 10 months. Additional migration of BPA from can coatings to liquid formula during the 10-month storage period at room temperature was observed for 9 of the 21 products, with increases in BPA levels ranging from 29.8 to 110%. Significant differences between the 2007 and 2008 results (P = 0.026) were observed for only one brand of product, which had the lowest BPA levels in the 2007 survey. The BPA levels in the milk-based formula products analyzed in 2008 (mean, 6.8 ng/g) were significantly higher (P = 0.00023) than those in the milk-based formula products analyzed in 2007 (mean, 5.0 ng/g), whereas the differences in BPA levels between the soya-based formula products analyzed in 2008 (mean, 5.3 ng/g) and those analyzed in 2007 (mean, 5.8 ng/g) were not significant (P = 0.097). No obvious correlation between the product expiration date and the level of BPA migration from can coatings was observed.

An isotope dilution headspace method with gas chromatography-mass spectrometry for determination of propylene oxide in food.

A method based on isotope dilution headspace and gas chromatography-mass spectrometry was developed for the determination of propylene oxide in foods. Optimum method sensitivity was achieved by the addition of NaCl in water at saturation and with the sample solution incubated at 90 degrees C. The method had good repeatability with relative standard deviations of 6.0, 7.6 and 2.2% at 5, 20 and 40 microg l(-1), respectively. The method was used to determine propylene oxide in 36 selected food composite samples from the 2007 Canadian total diet study. Propylene oxide was not detected in any samples analyzed with an average method detection limit of 0.5 ng g(-1). Hydrolysis of propylene oxide in water was observed as a first-order reaction with a half-life of 15 h at room temperature and less than 10 min at 90 degrees C. This confirms that it is very unlikely to find propylene oxide in foods as consumed due to its volatility and reaction with water.

Bisphenol a in baby food products in glass jars with metal lids from Canadian markets.

A method based on solid phase extraction and derivatization with acetic anhydride followed by gas chromatography-mass spectrometry was validated for the determination of bisphenol A (BPA) in baby foods. The average method detection limit (MDL) was 0.18 ng/g for a 5 g sample. Method repeatability was demonstrated with the replicate analyses of various different types of baby foods; relative standard deviations (RSD) ranged from 1.2 to 16.1% with an average of 8.7%. Extraction recoveries ranged from 93.5 to 102.5% for different types of baby foods spiked at levels of 1-8 ng/g. This method was used to analyze 122 baby food products of 7 brands in glass jars with metal lids for BPA. The presence of BPA could not be confirmed and quantified for 23 of the 122 products due to interference from sample matrices. For the other 99 products, 15% had BPA levels of less than the average MDL, about 70% had BPA levels of less than 1 ng/g, and the average BPA levels in all 99 products was 1.1 ng/g. The average BPA level in the baby food products from brand E (3.9 ng/g) is higher than the average BPA levels in the products from the other brands (0.54-1.1 ng/g). The highest level of BPA, 7.2 ng/g, was found in two products from brand E as well. The average BPA level in the fruit products from all brands (0.60 ng/g) is lower than those in the mixed-dish products (1.1 ng/g) and the vegetable products (1.2 ng/g).

Levels of bisphenol A in canned soft drink products in Canadian markets.

The method developed previously for the determination of bisphenol A (BPA) in liquid infant formula was adapted and validated for determination of BPA in soft drink products. This method was based on solid phase extraction and derivatization with acetic anhydride followed by gas chromatography-mass spectrometry in selected-ion monitoring mode. The average method detection limit was 0.045 microg/L for a 10 mL sample. The average extraction recoveries were 101 and 99.9% obtained with seven different soft drink products spiked with BPA at 0.5 and 2.5 microg/L, respectively. Good repeatability of the method was observed with replicate analyses of seven different soft drinks; relative standard deviations ranged from 1.3 to 6.6%. This method was used to analyze samples of 72 canned soft drink products for BPA. Except for three products from which BPA-d16 could not be recovered at all due to interference of product compositions (e.g., quinine hydrochloride in tonic water), BPA was detected in samples of all the other products at levels ranging from 0.032 to 4.5 microg/L. About 75% of the products had BPA levels of <0.5 microg/L, and 85% of the products had BPA levels of <1 microg/L. Exposure to BPA through consumption of canned soft drink products is low; dietary intake of BPA was estimated at 0.027 microg/kg of body weight/day on the basis of the consumption of one canned soft drink with the highest BPA level (4.5 microg/L) for an adult with a 60 kg body weight, well below the provisional tolerable daily intake of 25 microg/kg of body weight/day established by Health Canada.

Migration of bisphenol A from polycarbonate baby and water bottles into water under severe conditions.

The isotope dilution headspace solid-phase microextraction and gas chromatography-mass spectrometry method for bisphenol A (BPA) developed previously was used successfully in a BPA migration study at 70 degrees C of polycarbonate baby and reusable water bottles recently sold in Canada by using the whole bottles instead of pieces cut from the bottles. Migration of BPA from the PC bottles heated at 70 degrees C was found to increase over the time in the quadratic equations. Migration levels of BPA in water varied from 228 to 521 microg L (-1) or from 0.26 to 0.90 microg cm (-2) after being heated at 70 degrees C for 6 days. The average migration rates of BPA from the PC bottles into water at 70 degrees C ranged from 1.84 to 4.83 ng cm (-2) h (-1).

Determination of bisphenol A in water by isotope dilution headspace solid-phase microextraction and gas chromatography/mass spectrometry without derivatization.

The original solid-phase microextraction (SPME) fibers use an epoxy resin adhesive that releases bisphenol A (BPA) during thermal desorption of the fiber. This adversely affects the method detection limit and accuracy when these products are used for the determination of BPA. In this work, 5 new metal alloy SPME fibers that do not use epoxy resins were compared for the extraction of BPA in water. The performance of the optimum SPME fiber with 60 microm carbowax-polyethylene glycol coating for the headspace SPME of BPA in water was investigated systematically under different extraction conditions. Salt was found to increase the partitioning of BPA from water into the headspace until saturation was reached. Partitioning of BPA from water into the headspace also increased at higher extraction temperatures, as did longer extraction times. However, extraction of BPA from water onto the SPME fiber was not improved for solutions adjusted to pH 2 compared to the unadjusted neutral solutions. The new BPA method showed good linearity over the concentration range of 2.5 to 40 microg/L [correlation coefficient (r2) = 0.995] . The method detection limit for BPA was 0.5 microg/L, while the instrument detection limit was as low as 0.05 microg/L. Good repeatability was observed for BPA at levels of 5 and 20 microg/L with relative standard deviation values < 10%. The automated headspace SPME method developed in this work was used to investigate migration of BPA from polycarbonate bottles into water, and levels of BPA in water ranged from 1.7 to 4.1 microg/L.

Survey of bisphenol A in bottled water products in Canada.

A method based on isotope dilution headspace solid-phase microextraction and gas chromatography/mass spectrometry was used to assess levels of bisphenol A (BPA) in 56 samples of bottled water products sold in Canada. Levels of BPA in samples of all 51 non-polycarbonate (PC) bottled water products were lower than the method detection limit (0.50 µg l(-1)). Levels of BPA in most bottled water products in PC carboys were low, ranging from <0.50 to 1.4 µg l(-1) with an average of 0.75 µg l(-1). However, BPA was detected at levels of 8.8 and 6.5 µg l(-1) in two bottles of the bottled water products in PC carboys from the same product analysed over a 5-week period, likely due to accidental or careless exposure of the products to heat (e.g. under the sun) during storage and/or transportation for extended periods of time.