[Development of a Fully Automated Blood Alcohol Analyzer and Its Application in Forensic Science]

Blood alcohol concentration detection has long relied on manual operations in the field of forensic identification, resulting in cumbersome workflows, low throughput, and substantial human error. Such drawbacks make it increasingly difficult to meet the growing demands for case-handling efficiency and evidentiary quality. To address these issues, this study presents a fully automatic blood alcohol analyzer (Puyu LSAP AI), developed in-house by integrating precision mechanical actuation, pneumatic flow-limited pipetting, and intelligent task scheduling technologies, which automates and reengineers the conventional workflow to establish a fully automated protocol for blood alcohol concentration detection. In accordance with the latest national standard, the system demonstrated excellent linearity over the mass concentration range of 0.10-3.00 mg/mL, with correlation coefficients r≥0.997. The limit of detection (LOD) and limit of quantification (LOQ) were 0.05 mg/mL and 0.10 mg/mL, respectively. Parallel analyses of 20 whole-blood samples with varying viscosities yielded relative deviations consistently ranging from 1% to 5%, while relative standard deviations from repeatability tests were below 2.5% (n=6). No carryover contamination was observed during alternating injections of high-concentration samples (5 mg/mL) and blank specimens, and continuous high-throughput operation for 24 h was completed without mechanical or communication malfunctions. This analyzer has been deployed for routine forensic blood alcohol concentration detection, achieving fully automated, unattended, closed-loop operation throughout the entire analytical workflow. Its core technical components have been domestically developed, while the software and hardware architectures have been comprehensively decoupled to improve modularity and maintainability. The system meets national standards for precision, accuracy, and full-process digital compliance. It significantly improves the case-handling efficiency and evidentiary quality, offering technical support and a practical application paradigm for the intelligent and automated transformation of forensic science instrumentation.