Determination of mercury in minerals by cold atomic absorption spectrometry with direct introduction of sample

The sample was directly introduced without off-line chemical pretreatment.After pyrolysis and amalgamation,the mercury was determined by cold atomic absorption spectrometry at 253.65 nm.Optimal experimental conditions were discussed,including the sampling amount,determination mode,background control and selection of instrumental analysis conditions.The linear range of method was 0.1-600 ng,and the detection limit was 0.000 7 μg/g.The proposed method was applied to the determination of mercury in two reference mineral samples,whose results were consistent with the certified values.The relative standard deviations(RSD,n=7) were 3.3 % and 1.1 %,respectively.The mercury-containing mineral samples such as copper concentrate,manganese ore and zinc ore were determined by this method,as well as by cold atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry after digestion.It took only 5 min to determine one sample.The results showed that there was no significant difference.The dosage of sample required in this method was small,which enabled it more applicable to the testing of batch samples.