TY - JOUR
T1 - Determination of 236U/ 238U and 235U/ 238U isotope ratios in human urine by inductively coupled plasma mass spectrometry
AU - Gray, Patrick J.
AU - Zhang, Lingsu
AU - Xu, Hanna
AU - McDiarmid, Melissa
AU - Squibb, Katherine
AU - Centeno, José A.
PY - 2012/11
Y1 - 2012/11
N2 - Isotopic ratios of urinary uranium (U) provide a decisive tool in diagnosing a patient's potential exposure to depleted uranium (DU). This study investigated the measurement of urinary 236U/ 238U and 235U/ 238U ratios of ultra trace concentrations using a sector field inductively coupled plasma mass spectrometer (ICP-MS). Uranium was separated from the urinary matrix and pre-concentrated by co-precipitation with calcium and magnesium after addition of ammonium hydroxide. The precipitates were collected, dissolved and analyzed by ICP-MS. 235U/ 238U and 236U/ 238U ratios were measured using a desolvating sample introduction system and a sector field ICP-MS. These ratios were accurately measured in samples containing as low as 5ngL -1 U. 236U measurement was hindered by abundance sensitivity limitations and uranium hydride ( 235UH) formation. Measured 235U/ 238U and 236U/ 238U ratios were about 7×10 -3 and -6, respectively, in urine samples from patients not exposed to DU. The 235U/ 238U ratio was consistently about 2×10 -3 in 12 urine samples from patients with embedded fragments of DU, while the corresponding ratio of 236U/ 238U ranged from 9×10 -6 to 33×10 -6. This wide range in 236U/ 238U ratios might suggest different sources of depleted uranium in those DU-urine samples. It is proposed that 235U/ 238U and 236U/ 238U ratios are 7×10 -3 and -6, respectively, in urine samples from individuals not exposed to DU, and 2×10 -3 and >7×10 -6, respectively, in urine samples from DU-exposed individuals.
AB - Isotopic ratios of urinary uranium (U) provide a decisive tool in diagnosing a patient's potential exposure to depleted uranium (DU). This study investigated the measurement of urinary 236U/ 238U and 235U/ 238U ratios of ultra trace concentrations using a sector field inductively coupled plasma mass spectrometer (ICP-MS). Uranium was separated from the urinary matrix and pre-concentrated by co-precipitation with calcium and magnesium after addition of ammonium hydroxide. The precipitates were collected, dissolved and analyzed by ICP-MS. 235U/ 238U and 236U/ 238U ratios were measured using a desolvating sample introduction system and a sector field ICP-MS. These ratios were accurately measured in samples containing as low as 5ngL -1 U. 236U measurement was hindered by abundance sensitivity limitations and uranium hydride ( 235UH) formation. Measured 235U/ 238U and 236U/ 238U ratios were about 7×10 -3 and -6, respectively, in urine samples from patients not exposed to DU. The 235U/ 238U ratio was consistently about 2×10 -3 in 12 urine samples from patients with embedded fragments of DU, while the corresponding ratio of 236U/ 238U ranged from 9×10 -6 to 33×10 -6. This wide range in 236U/ 238U ratios might suggest different sources of depleted uranium in those DU-urine samples. It is proposed that 235U/ 238U and 236U/ 238U ratios are 7×10 -3 and -6, respectively, in urine samples from individuals not exposed to DU, and 2×10 -3 and >7×10 -6, respectively, in urine samples from DU-exposed individuals.
KW - Depleted uranium
KW - Inductively coupled plasma mass spectrometry
KW - Uranium
KW - Uranium isotope ratio
KW - Urine
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U2 - 10.1016/j.microc.2012.07.004
DO - 10.1016/j.microc.2012.07.004
M3 - Article
AN - SCOPUS:84867854948
SN - 0026-265X
VL - 105
SP - 94
EP - 100
JO - Microchemical Journal
JF - Microchemical Journal
ER -