Application of a permethrin immunosorbent assay method to residential soil and dust samples.

A low-cost, high throughput bioanalytical screening method was developed for monitoring cis/trans-permethrin in dust and soil samples. The method consisted of a simple sample preparation procedure [sonication with dichloromethane followed by a solvent exchange into methanol:water (1:1)] with bioanalytical detection using a magnetic particle enzyme-linked immunosorbent assay (ELISA). Quantitative recoveries (83-126%) of cis/trans-permethrin were obtained for spiked soil and dust samples. The percent difference of duplicate ELISA analyses was within +/- 20% for standards and +/- 35% for samples. Similar sample preparation procedures were used for the conventional gas chromatography/mass spectrometry (GC/MS) analysis except that additional cleanup steps were required. Recoveries of cis/trans-permethrin ranged from 81 to 108% for spiked soil and dust samples by GC/MS. The ELISA-derived permethrin concentrations were highly correlated with the GC/MS-derived sum of cis/trans-permethrin concentrations with a correlation coefficient (r) of 0.986. The ELISA method provided a rapid qualitative screen for cis/trans-permethrin in soil and dust while providing a higher sample throughput with a lower cost as compared to the GC/MS method. The ELISA can be applied as a complementary, low-cost screening tool to prioritize and rank samples prior to instrumental analysis for exposure studies.

Little Cigars vs 3R4F Cigarette: Physical Properties and HPHC Yields.

OBJECTIVE: Our objective was to characterize physical properties and semivolatile harmful and potentially harmful constituent yields in the mainstream smoke (MSS) of 4 popular little cigars compared to the 3R4F reference cigarette. METHODS: We used the ISO and Canadian Intense Regimen protocols to generate MSS for Cheyenne (Full Flavor and Menthol) and Swisher Sweets (Original and Sweet Cherry) little cigars; and the 3R4F. We examined physical properties such as length, tobacco filler mass, pressure drop, and ventilation for each product. Nicotine, benzo[a]pyrene, and tobacco-specific nitrosamine (TSNA) yields were determined in the MSS. RESULTS: Little cigars were longer (~15mm), contained more tobacco filler (100-200 mg), and had a higher pressure drop (~1.3X) compared to the 3R4F. Ventilation holes were found only on the filter paper of the 3R4F. Nicotine transmitted to the MSS was similar for all products under the intense smoking protocol. The highest yields of TSNAs and benzo(a)pyrene were measured for the little cigars. CONCLUSIONS: Little cigars may deliver similar levels of nicotine but higher levels of carcinogens to the MSS compared to cigarettes. Thus, previous reports on the toxicity of tobacco smoke based on cigarettes might not apply to little cigar products.

Custom Mentholation of Commercial Cigarettes for Research Purposes.

In the U.S. menthol remains the sole permitted characterizing cigarette flavor additive in part because efforts to link menthol cigarette use to increased tobacco-related disease risk have been inconclusive. To perform definitive studies, cigarettes that differ only in menthol content are required, yet these are not commercially available. We prepared research cigarettes differing only in menthol content by deposition of L-menthol vapor directly onto commercial nonmenthol cigarettes, and developed a method to measure a cigarette's menthol and nicotine content. With our custom-mentholation technique we achieved the desired moderately high menthol content (as compared to commercial brands) of 6.7 ± 1.0 mg/g (n = 25) without perturbing the cigarettes' nicotine content (17.7 ± 0.7 mg/g [n = 25]). We also characterized other pertinent attributes of our custom-mentholated cigarettes, including percent transmission of menthol and nicotine to mainstream smoke and the rate of loss of menthol over time during storage at room temperature. We are currently using this simple mentholation technique to investigate the differences in human exposure to selected chemicals in cigarette smoke due only to the presence of the added menthol. Our cigarettes will also aid in the elucidation of the effects of menthol on the toxicity of tobacco smoke.