HG-AFS Determination of Total Selenium in Soil with Ultrasonically Assisted Sample Digestion

As a modification for the standard method (NY/T 1104-2006),ultrasonic treatment for 20 min was adopted in the HNO3-HClO4 acid digestion of soil samples. Total selenium was determined by HG-AFS as described. Linearity range found was within 20 μg·L-1. Detection limit (3s/k) was found to be 0.01 μg·L-1. Result of average total selenium (0.13 μg·g-1) determined in a CRM (GBW 07419) was in consistency with the certified value (0.14±0.04 μg·g-1). Tests for recovery and precision were made by standard addition method at 3 different concentration levels,values of recovery and RSD′s (n=11) found were in the ranges of 90%-112% and 1.8%-3.7% respectively.