Implementation of Developed Quality Control Material for Performance Checkup of Alcohol Breath Analyzer in Bangkok Metropolitan Police Station

Abstract

The Land Traffic Act has defined the penalty for driving under the influence of alcohol when a blood alcohol content is higher than 50 mg/dL, which is routinely monitored by police officers using electrochemical analyzer to measure the breath alcohol concentration. Presently, calibration and maintenance of analyzers are common procedures on the schedule (every 6 months). However, there is a lack of definite guidelines and continuous control due to the high cost of materials. In addition, the measurement results may be inaccurate due to the lifetime of materials or improper storage of analyzers. This study aimed to test the performance of control materials that have been locally developed with alcohol breath analyzers at Bangkok Metropolitan Police Station. A cross-sectional analytical study was performed in 77 analyzers 2 models. Control material concentrations at 28, 67, and 134 mg/dL were tested by a wet bath simulator. The results showed that 55 out of 77 alcohol breath analyzers which were calibrated within 4 months had %Total error (TE) of 16.95%, 11.43%, and 8.60% at 28, 67, and 134 mg/dL, respectively, which met 20% CLIA’s TE criteria. However, analyzers that have their last calibration more than 4 months had %TE above the accepted criteria. In conclusion, the developed control material revealed valuable data-related analyzer calibration guidelines. Analyzers should schedule the calibration every 4 months (3 times/year) to achieve the accuracy and reliability of the test results.