Determination of Hydrogen Cyanide in Workplaces Air by Automatic Flow Injection Analysis

Objective To establish a method for the determination of hydrogen cyanide in the air at workplaces by automatic flow injection analysis.

Method Hydrogen cyanide in air sample collected from workplaces was first absorbed in sodium hydroxide liquid, and then quantitatively detected by automatic flow injection analysis, which consisted of online distillation, separation and real-time coloration.

Results The concentration of hydrogen cyanide in the air showed a good linear relationships in the range of(0.001~0.080) μg/L, the correlation coefficient (r) was 0.999 7. The minimum detectable concentration in a 2.0 L air sample was 0.000 30 mg/m³; the average recovery of standard addition for simulated air sample was 91.0%~99.8%, and the relative standard deviation was 1.4%~3.1%.

Conclusion This method was proved to be simple with higher sensitivity, good precision and accuracy, it was suitable for the determination of hydrogen cyanide in the air at workplaces.