Determination of Inorganic Arsenic in Soil Using Ultrasonic Extraction-Atomic Fluorescence Spectrometry

Objective To establish a method for the determination of inorganic arsenic in soil by using ultrasonic extraction-sequence injection hydride generation-atomic fluorescence spectrometry.Methods Inorganic arsenic in soil samples was extracted for 90 min by ultrasonic digestion.With 6 mol/L hydrochloric acid solution for extraction agents,with 10 g/L borohydride potassium-5 g/L potassium hydroxide as reductant,with 4% hydrochloric acid as carrying current,inorganic arsenic in soil was determined by HG-AFS.Results When the concentration of arsenic was 0.025-100 μg/L,the regression equation got was I=67.19c+75.54,and the correlation coefficient was 0.999 7,showing a good linear relationship.According to three times the signal-to-noise ratio,the limit of detection was 0.025 μg/L.The relative standard deviation was 0.93% and the average recovery rates were 98.8%-103.3%.Conclusion The method is simple,rapid,accurate,sensitive and is applicable to the determination of inorganic arsenic in soil.