Evaluation of headspace-gas chromatography/mass spectrometry for the analysis of benzene in vitamin C drinks; pitfalls of headspace in benzene detection.
ABSTRACT Recently, there have been reports regarding the presence of benzene in vitamin C drinks. This is caused by sodium benzoate and ascorbic acid (vitamin C), which can react together to induce benzene formation. While the headspace gas chromatography method is well known for the detection of benzene, there could be pitfalls in the process of benzene extraction. This study was performed to check if benzene could be generated under high-temperature incubation conditions. As a result, the amount of benzene detected by headspace-gas chromatography/mass spectrometry (HSGC/MS) was affected by temperature changes. As the temperature of the sample vial was increased, newly generated benzene from the headspace also increased, causing false-positive determination of benzene. Although 80 degrees C is generally accepted for the temperature of headspace sample vials, lower temperatures, such as 40 degrees C, minimize the false-positive identification of benzene. Considering that this minimization allows benzene to be quantified at around 5 ppb, this lower temperature should definitely be considered since benzene, which is formed in sodium benzoate, can appear in vitamin C drinks under certain circumstances. The proposed analysis method of benzene in vitamin C drinks by HSGC/MS at 40 degrees C is an accurate and universal method for the monitoring of benzene without false-positive identification.
Article: Toxicology of solvents.[show abstract] [hide abstract]
ABSTRACT: Solvents encountered in industry are for the most part organic liquids, although gases and solids are occasionally utilized for their solvent properties. Organic solvents may be pure substances such as carbon tetrachloride, or they may be complex solutions themselves like, for instance, petroleum-derived solvents. When used in chemical processes, solvents are not considered to be one of the reactants. Although solvents may be classified in various ways, it is usually most satisfactory for the toxicologist to group them by chemical class. In the industrial context, adverse effects from solvent exposure liquids are quite volatile. Many of them are also capable of penetrating the skin so dermal absorption is another important possibility to be kept in mind. The classes of solvents to be examined in this review include the hydrocarbons, halogenated hydrocarbons, other organic compounds with various functional groups, and complex solvents.AIHAJ 12/1986; 47(11):704-7.
- [show abstract] [hide abstract]
ABSTRACT: Recently, the combination of sodium or potassium benzoate with ascorbic acid was shown to produce low levels (ng/g) of benzene in fruit-flavored soft drinks. The presence of benzene also was reported in butter, eggs, meat, and certain fruits; levels of these findings ranged from 0.5 ng/g in butter to 500-1900 ng/g in eggs. Because benzoates are widely used as food preservatives, a limited survey of other foods containing added benzoate salts was conducted to investigate the potential for benzene formation. Selected foods that did not contain added benzoates but were previously reported to contain benzene were analyzed for comparison. More than 50 foods were analyzed by purge-and-trap or static headspace concentration and capillary gas chromatography. Benzene was quantitated by using the method of standard additions, and its identity was confirmed by mass selective detection. Results of this limited survey show that foods without added benzoates (including eggs) contained benzene at levels equal to or less than 2 ng/g. Slightly higher levels were present in some foods and beverages containing both ascorbic acid and sodium benzoate.Journal of AOAC International 76(6):1213-9. · 1.23 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: A sensitive method is presented for the fast screening and determination of residual class 1 solvents (1,1-dichloroethene, 1,2-dichloroethane, 1,1,1-trichloroethane, carbon tetrachloride and benzene) in pharmaceutical products. The applicability of a headspace (HS) autosampler in combination with GC equipped with a programmed temperature vaporizer (PTV) and a MS detector is explored. Different injection techniques were compared. The benefits of using solvent vent injection instead of split or splitless-hot injection for the measurement of volatile compounds are shown: better peak shapes, better signal-to-noise ratios, and hence better detection limits. The proposed method is extremely sensitive. The limits of detection ranged from 4.9 ppt (benzene) to 7.9 ppt (1,2-dichloroethane) and precision (measured as the relative standard deviation) was equal to or lower than 12% in all cases. The method was applied to the determination of residual solvents in nine different pharmaceutical products. The analytical performance of the method shows that it is appropriate for the determination of residual class 1 solvents and has much lower detection limits than the concentration limits proposed by the International Conference on Harmonization (ICH) of Technical Requirements for the Registration of Pharmaceuticals for Human Use. The proposed method achieves a clear improvement in sensitivity with respect to conventional headspace methods due to the use of the PTV.Journal of Chromatography 03/2007; 1141(1):123-30. · 4.61 Impact Factor