DETERMINATION OF MERCURY IN SALIVA WITH A FLOW-INJECTION SYSTEM

A simple, fast and reliable method, with a low detection limit, has be en developed for the determination of total mercury in saliva samples. The method uses a brominating reagent, followed by on-line addition o f KMnO4 at room temperature to convert organically bound mercury to in organic mercury ions, and determines mercury by flow-injection cold-va pour atomic absorption spectrometry. Using the method described, compl ete recoveries of five mercury compounds from saliva were attained. Re sults obtained on real samples using the new method were comparable to that obtained using the established method with batch system. The det ection limit of this method, based on three standard deviations of the blank, is 0.05 mu g l(-1) Hg in a saliva sample of 500 mu l. A sample throughput of 80 measurements per hour is possible with the method. T he calibration curves are linear up to 20 mu g l(-1) and the dynamic r ange extends to 40 mu g l(-1) Hg. At a concentration of 1 mu g l(-1) m ercury in saliva, the relative standard deviation is about 2% for 11 r eplicates; a total volume of 0.5 ml saliva is required for three repli cates.