Rapid versatile method for determining mercury at sub-nanogram levels by cold-vapour atomic-absorption spectroscopy

Abstract

This paper describes a rapid, dual-channel method of cold-vapour atomicabsorption spectroscopy for determining mercury which produces reproducible results to within ±2% of the average peak height for a number of 50-ng injections giving 50% of full-scale deflection (f.s.d.). The method has a detection limit of 0.25 ng (2:1 signal to noise ratio) and the blank values are low, e.g., 10 ml of a mixture of 5% nitric acid and 0.01% potassium dichromate at a nitrogen flow-rate of 500ml min^–1 yields a blank of 1% f.s.d. (recorder: 10 mV, × 6 scale expansion).