Phosphates, naturally containing trace amounts of uranium, were examined using direct γ-ray spectrometry. Both normal and
Compton-suppressed counting modes were utilized. The 1001 keV photo peak of the second daughter of 238U was chosen because of its isolation from other, potentially interfering peaks. The findings suggest that with the aid of
Compton suppression, it is possible to quantify low uranium levels in phosphates using samples sizes of order 10 grams within
an accuracy of 5%. The uranium content was determined in several sample types and was found to range from 60±4 to 70±8 μg/g,
depending on the sample composition. This investigation also considered the effects of sample size, counting time, and counting
technique as sources of precision maximization. This work has shown that only a small amount of phosphate is needed to determine
the constituent concentration, instead of the standard several hundred grams of material.