Abstract
A preconcentration method with combined diethyldithiocarbamate (DDTC) and iron (III) was studied for X-ray fluorescence determination of molybdenum in sea water.
Ten grams of sodium chloride, one milligram of iron (III) and 10ml of 10w/v% sodium acetate buffer were added to 500ml of sample, which was adjusted to pH3.0, by adding 3ml of 2w/v% DDTC solution. The coprecipitate containing molybdenum was then collected on a membrane filter paper (0.45μm), dried at room temperature and delivered to the X-ray fluorescence analysis.
Limits of detection and lower determination of this method were 0.3 μg/l and 0.9μg/l, respectively. This method was applied to determination of molybdenum in sea water. The analytical results found by the calibration curve method were in good agreement with those by the standard addition method. The relative standard deviation in respective five determinations of sea water was 2.9%. It was concluded that the calibration curve method was available for the determination of molybdenum in sea water.
