Determination of arsenic and antimony in biological materials by solvent extraction and neutron activation

Arsenic and antimony in digested biological samples can be extracted with pyrrolidinecarbodithioate at pH 1 into chloroform and stripped with nitric acid for neutron-activation analysis (NAA). The extraction method eliminates interferences from matrix species, including Br and Na, making the accurate determination of low levels of As and Sb in biological materials feasible. The detection limits under the experimental conditions used are 0.005 and 0.006 mug/g for arsenic and antimony, respectively. A comparison of the results obtained for As and Sb in NBS biological standards by this method and by non-destructive instrumental neutron-activation analysis (INAA) is also given.