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Biomedical subjects

J A Wenninger

Publications and source records attributed to J A Wenninger.

9 recordsLinked to original sources
PubMed1983

N-nitroso-N-methyloctadecylamine in hair-care products.

Fifty-three cosmetic products containing one or more of the ingredients N,N-dimethyloctadecylamine oxide, N,N-dimethyloctadecylamine and N-benzyl-N,N-dimethyloctadecylammonium chloride were analysed for N-nitroso-N-methyloctadecylamine by gas chromatography with detection by a Thermal Energy Analyzer. [1-14C]N-Nitroso-N-methyloctadecylamine was used as an internal standard. Eight of 11 products containing N,N-dimethyloctadecylamine oxide and three of 38 products containing N-benzyl-N,N-dimethyloctadecylammonium chloride were found to contain N-nitroso-N-methyloctadecylamine at levels ranging from 28 to 969 ppb. In photolysis experiments, all of these products exhibited a loss of Thermal Energy Analyzer response for N-nitroso-N-methyloctadecylamine following irradiation by ultraviolet light. In two cases, the presence of N-nitroso-N-methyloctadecylamine was confirmed by combined gas chromatography-mass spectrometry.

Chromatography, Gas↗
PubMed1982

N-nitroso-N-methyldodecylamine and N-nitroso-N-methyltetradecylamine in hair-care products.

N-Nitroso-N-methyldodecylamine and N-nitroso-N-methyltetradecylamine, which cause urinary bladder tumours in experimental animals, were detected in several hair-care products formulated with N,N-dimethyldodecylamine oxide. Quantitative determinations were made using a gas-liquid chromatograph interfaced with a thermal energy analyser and using [1-14C]N-nitroso-N-methyldodecylamine as an internal standard. The presence of the two nitrosamines was confirmed by high-pressure liquid chromatography with a thermal energy analyser as detector, by photolysis of samples and by combined gas chromatography-mass spectometry. To test the reproducibility of the method, a single shampoo was selected for replicate analysis and was found to contain 90 +/- 8 ppb N-nitroso-N-methyldodecylamine and 37 +/- 11 ppb N-nitroso-N-methyltetradecylamine. Levels of N-nitroso-N-methyldodecylamine in other hair-care products ranged from 11 to 873 ppb and those of n-nitroso-N-methyltetradecylamine from 8 to 254 ppb.

Carcinogens↗
PubMedDate not supplied

Fluorometric determination of benzylideneacetone in fragrance products by liquid chromatography with post-column derivatization.

A method is described for the liquid chromatographic (LC)-fluorometric determination of benzylideneacetone in fragrance products. Benzylideneacetone is first separated from other fragrance ingredients by LC and then reacted post-column with a methanolic solution of isonicotinic acid hydrazide and aluminum nitrate. The reactants are maintained at 65 degrees C for about 1.5 min to quantitatively form the fluorescent isonicotinoyl hydrazone derivative of benzylideneacetone. The aluminum ion forms a complex with the hydrazone to enhance the fluorescence of the derivative. The amount of benzylideneacetone is determined by measuring the intensity of the fluorescence emitted by the hydrazone derivative and comparing that value with those obtained for derivatized standards. Recovery studies were conducted by spiking commercial fragrances with benzylideneacetone at concentrations of 0.01, 0.05, and 0.1% (w/v). Recoveries ranged from 98 to 104% with a mean recovery of 100.2% and a standard deviation of 2.4%.

Butanones↗
PubMedDate not supplied

Liquid chromatographic separation and fluorometric determination of cis- and trans-isoeugenol in perfumes, colognes, and toilet waters.

A liquid chromatographic (LC)-fluorometric method is described for the determination of cis- and trans-isoeugenol (2-methoxy-4-propenylphenol) in perfumes, colognes, and toilet waters. A test portion of the product is added to diethyl ether, and the isoeugenol isomers are extracted with sodium hydroxide solution. The basic extract is then acidified, and the isoeugenol isomers are extracted with isooctane. Aliquots of the isooctane extract are analyzed by using a silver ion cation exchange LC column interfaced to a spectrophotofluorometer. Each isomer in the product is determined by comparing its fluorescence emission intensity with that of an external standard consisting of a mixture of both isomers in which the relative concentration of each has been determined. Average recoveries from various commercial fragrances fortified with a mixture of cis- and trans-isoeugenol with total isoeugenol content of 0.1, 0.5, and 4.0 mg/mL ranged from 87 to 105% for the trans-isomer (SD = 4.6%) and from 83 to 113% for the cis-isomer (SD = 6.7%). The limit of determination is approximately 0.002 mg/mL.

Chromatography, Gas↗
PubMedDate not supplied

Liquid chromatographic-fluorometric determination of cinnamyl alcohol in perfumes, colognes, and toilet waters.

A liquid chromatographic (LC) method is described for the determination of cinnamyl alcohol (3-phenyl-2-propen-1-ol) in fragrance compositions. The fragrance product is partially cleaned up by diluting the fragrance with a 95% ethanol-water mixture and passing it through a short column containing RP-8 packing. An aliquot of the effluent is then analyzed by LC using an RP-18 column interfaced to a spectrophotofluorometer equipped with double monochromators. The fluorescence emission intensity of the eluted cinnamyl alcohol is measured and compared with that of a standard to calculate the amount of cinnamyl alcohol present. Recoveries from fragrance products fortified with cinnamyl alcohol at levels ranging from 0.0020 to 0.060 mg/mL ranged from 85 to 105% with a mean of 94%. The lowest level of determination was 0.0005 mg/mL.

1-Propanol↗
PubMedDate not supplied

Screening cosmetic products for N-nitroso compounds by chemiluminescent determination of nitric oxide.

Cosmetic products were screened for total N-nitroso compounds by chemiluminescent measurement of nitric oxide liberated by the reductive cleavage of the N-nitroso group. The cosmetic was first partitioned between methylene chloride and water to separate polar and nonpolar N-nitroso compounds. Each extract was then examined for the presence of N-nitroso compounds by adding the cleavage reagent and sweeping the nitric oxide formed into a chemiluminescent analyzer. Although the method is not intended to be quantitative, recovery studies were conducted to determine measurable levels. Recovery studies of polar N-nitroso compounds were conducted by adding N-nitrosodiethanolamine (NDELA) to a cream, a shampoo, and a lotion at 3 levels, i.e., 80, 320, and 960 ppb, and then determining NDELA by the method. Recoveries ranged from 48 to 83% (mean 68%; SD = 11.9). For recoveries of nonpolar N-nitroso compounds, 100, 200, and 500 ppb of N-nitrosomethyltetradecylamine were added to the 3 cosmetic products. Recoveries ranged from 58 to 70% (mean 63%; SD = 5.3).

Cosmetics↗
PubMedDate not supplied

Determination of 2-ethylhexyl 4-(N-methyl-N-nitrosamino) benzoate in commercial sunscreens and cosmetic products.

An analytical method has been developed for determination of 2-ethylhexyl 4-(N-methyl-N-nitrosamino) benzoate (NMPABAO), a nitrosamine contaminant in sunscreen products containing 2-ethylhexyl 4-(N,N-dimethylamino) benzoate (Padimate O). The method involves extraction of NMPABAO by column chromatography followed by liquid chromatographic separation and analysis wit a nitric oxide detector. To confirm the presence of NMPABAO in sunscreen products, the N-nitrosamine was synthesized and its structure was determined by infrared spectrophotometry, nuclear magnetic resonance spectrometry, and mass spectrometry (MS). For method validation, recovery studies were performed on a commercial suntan lotion, cream, and gel. Recoveries of NMPABAO added to representative test samples averaged 83%. The method has an estimated detection limit of 30 ppb. The method was used to analyze 25 commercial cosmetic and sunscreen products containing Padimate O. Eleven products contained NMPABAO at levels ranging from 160 to 21000 ppb. NMPABAO presence in 4 products was confirmed by MS at levels > or = 4000 ppb. The highest levels of NMPABAO were associated with products that contained the nitrite-releasing preservative 2-bromo-2-nitro-1,3-propanediol.

Carcinogens↗