A Comparison of Thermal and Epitherral Neutron Activation for the Measurement of Selenium in Vegetation

Determination of selenium in environmental standard reference materials by a .gamma.-.gamma. coincidence method using lithium-drifted germanium detectors

“…Instrumental neutron activation analysis has been used to measure Se in air particulates (9,10), fly ash (11), and coal (11)(12)(13). Two Se isotopes, 73Se (í1/2 = 120d) and 77mSe (f1/2 = 17.5s) are commonly employed (11)(12)(13)(14)(15), but the detection 0003-2700/80/0352-0765801.00/0 limits for both of these are well above Se concentrations in most geological and biological materials. A variety of radiochemical separation procedures have been successfully devised for the measurement of sub-ppm levels of Se in such matrices (16)(17)(18)(19)(20)(21).…”

Determination of selenium in environmental materials by neutron activation and inorganic ion exchange

“…Classically, selenium has been determined gravimetrically, volumetrically (9,10), and colorimetrically (11). Instrumentally, selenium can be measured by atomic absorption (12,13), gas chromatography (8), fluorescence (14,15), emission spectroscopy (16,17), and neutron activation with -ray spectroscopy (18)(19)(20)(21)(22). With the exception of -ray spectroscopy, methods of selenium determination require sample decomposition and preparatory chemistry.…”

“…Dissolve the residue from either dissolution procedure in 30 mL 6 M HC1. Cover and boil for 20 to Se(IV). Remove from the heat, add 2 mL H3P04, and let cool.…”