Optimization of parameters for trace inorganic mercury determination in urine by flow injection cold vapor AAS

The parameters of a flow injection mercury cold vapor atomic absorption spectroscopy system were optimized with respect to reagent concentration, carrier gas flow rate, acid carrier rate, and reaction coil length. Urine samples from workers exposed to mercury vapor as well as a urine reference standard were analyzed. It was shown that urine from workers exposed to elementary mercury vapor contains only inorganic mercury(II). The best conditions for the determination of inorganic mercury in urine included the following parameters: 500 μL sample volume, 300 mm reaction coil length, 80 mL/min carrier gas flow rate, 120 rpm pump speed, SnCl 2 5% (w/v) reductant solution in 5% (v/v) HCI, and HCl 3% (v/v) acid carrier.