Assessment of Smoking Status among Workers Using an Improved Colorimetric Method

Abstract

To monitor smoking status among workers, we improved the colorimetric method to detect cotinine and other nicotine metabolites in urine. In adding ethanol in the reaction mixture, the quantitative measurable time defined as the duration with more than 95% of the peak absorbance, extended to 80 min in contrast to 16 min in the original method. As the analytical condition, a aliquot of urine sample (0.5 ml) was mixed with 0.5 ml of ethanol, with 0.2 ml of 4 M acetate buffer (pH: 4.7), with 0.1 ml of 150 mM KCN, with 0.1 ml of 0.44 M chloramin and then with 0.5 ml of 78 mM barbituric acid. A linear relationship was observed between cotinine concentration up to 80 µM and absorbance at 508 nm (r=0.998, p<0.01). Mean levels of nicotine metabolites among non smokers a nd smokers were 4.9 and 47.4 µM cotinine equivalent, respectively. Sensitivity and specificity were 96.1% and 96.7%, respectively for nicotine metabolites concentration among workers (n=385) when adopting 6.9 µM cotinine equivalent as a cut off value and the area under the ROC curve was 0.982. This method can be applicable to quantitative detection of smoking status.

Tobacco chippers seeking assistance for smoking cessation: a case series

“…Indeed, colorimetric methods have some limitations; however, they are useful to distinguish between smokers and non-smokers, as well as to show changes in smoking behavior. 19,20 In TC no.…”