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K M Dubowski

Publications and source records attributed to K M Dubowski.

30 records · Page 2Linked to original sources
PubMedDate not supplied

Evaluation of commercial breath-alcohol simulators: further studies.

Exemplars of current commercial breath-alcohol simulators were studied to ascertain their suitability for control tests and as calibrators in breath-alcohol analysis. Temperature, effluent volumes and pressures, effluent-alcohol concentration, and alcohol depletion were measured for simulators coupled with various current alcohol analyzers. Effluent recirculation was found to extend the number of acceptable control test cycles by 3.2 x over nonrecirculation. We found substantial improvements in current commercial simulators and in their performance over those evaluated in 1979.

Breath Tests↗
PubMedDate not supplied

Field performance of current generation breath-alcohol simulators.

The between-run accuracy and reproducibility of vapor-alcohol control tests associated with quantitative evidential breath-alcohol testing in the field were evaluated. Control samples were generated at six separate sites with 34 degrees C TOXITEST II breath-alcohol simulators and analyzed by infrared spectrometry with Model 5000-D intoxilyzers in the recirculation mode. Control test results at target alcohol concentrations of 0.060, 0.080, 0.090, 0.100, 0.110, and 0.120 g/210 L (n = 779) were combined and analyzed by standard statistical methods. Results were correlated with target values, and the signed and absolute differences were calculated and analyzed. Data treatment included ANOVA, linear regression analysis, t statistics, and relative and cumulative frequency distributions of the differences. We found the performance of these current generation simulators in the field to be similarly satisfactory to that obtained in our laboratory evaluation. We further found that vapor-alcohol control samples generated with these devices conformed to established formal requirements and that they can serve as an effective quality assurance measure in evidential breath-alcohol analysis.

Breath Tests↗
PubMedDate not supplied

Alcohol analysis of stored whole-breath samples by automated gas chromatography.

A new method was developed to apply the advantages of automated gas chromatographic headspace analysis to delayed measurement of alcohol in whole breath (W-B). End-expiratory breath and vapor-alcohol samples were collected in sealed, heated 22-mL glass vials, stored for 0-15 days, and thereafter analyzed for alcohol by automated GC with aqueous calibrators without further sample preparation. The results were compared with those of direct alcohol determinations in closely adjacent breath samples by IR absorptiometry with an Intoxilyzer. The mean difference between 389 paired-sample breath-alcohol concentrations thus determined was close to zero; the correlation coefficient for linear regression of these results plus corresponding blanks was R=0.989. The new method is practical and reliable for law enforcement, clinical, and research applications of delayed breath-alcohol analysis.

Adult↗
PubMedDate not supplied

Response of breath-alcohol analyzers to acetone.

Quantitative evidential breath-alcohol analyzers and screening testers in each of the five current categories of analytical principle were examined for response to dynamically-generated acetone vapor concentrations of 3, 100, 150, 350, and 600 micrograms/210 Liters. Nine of the 13 instruments tested were unaffected by acetone at any of these concentrations; three solid-state (Taguchi) sensing devices and one device employing single-wavelength infrared spectrometry displayed responses to acetone at the two highest tested concentrations. In view of a breath-acetone literature survey for ambulatory subjects and other considerations, response of the tested devices to acetone is not considered to be a significant problem in breath-alcohol analysis for traffic law enforcement purposes.

Acetone↗
PubMedDate not supplied

Response of breath-alcohol analyzers to acetone: further studies.

Seven quantitative evidential breath-alcohol analyzers in three categories of analytical principle were tested for response to dynamically generated vapor acetone concentrations of 3, 100, 150, 350, and 600 micrograms/L and to alcohol-acetone vapor mixtures of 0.10 g alcohol/210 L and 350 or 600 micrograms acetone/L. No significant interference by acetone at any of these concentrations was found in four of the tested instruments. Two devices employing single wavelength infrared spectrometry displayed no unacceptable responses to acetone in concentrations to 350 micrograms/L, and one device employing solid-state (Taguchi) sensing was found to be significantly sensitive to acetone at the two highest tested concentrations. Except for the latter device, response to acetone of those instruments tested is not considered to be a significant problem in breath-alcohol analysis for traffic law enforcement or other purposes.

Acetone↗