Nonspecificity of Urinary Lead Measurements by Atomic Absorption Spectroscopy

[摘要] Lead measurements by direct AAS at 217 nm on a pooled urine sample gave values of 57 µg/l by the method of standard additions. In contrast, dithizone procedures gave values of 15-20 µg/l. Studies demonstrated that various urine salts and organic compounds contributed to the absorbance at 217 nm. These native urine materials also give a similar absorbance value at 220 nm, a line not related to lead emitted by the lead hollow cathode tube. Thus, correction of the nonlead absorbance was possible by subtracting the A220 from A217. Utilizing this correction, the standard addition procedure gave values of 12 µg/l. The correction technic was also applied to the lead isolation-concentration technic of Kopito and Shwachman (3) which employs bismuth coprecipitation. The simplicity of operations, increased sensitivity and reproducibility obtained by coupling the AAS correction technic with bismuth coprecipitation recommends it as a method for serious consideration.

[学科分类] 过敏症与临床免疫学