Evaluation of the uncertainty of blood lead determination using GUM and Monte Carlo methods

Objective Blood lead detection falls under trace analysis. To improve the accuracy and reliability of blood lead determination, the study on measurement uncertainty was conducted to explore suitable evaluation methods for blood lead determination.

Methods Following the standard GBZ/T 316.2—2018 Determination of Lead in Blood—Part 2: Inductively Coupled Plasma Mass Spectrometry, the measurement uncertainty associated with the determination of lead content in a certified reference material of lyophilized whole blood (295 ± 30) μg/L was evaluated using the guide to the expression of uncertainty in measurement (GUM) and the Monte Carlo method (MCM), and a comparative analysis was conducted.

Results The result obtained by the GUM was (297 ± 12) μg/L, while that by MCM was (297 ± 11) μg/L. The two methods gave closely comparable outcomes.

Conclusions The GUM and MCM evaluations were highly consistent when the measurement model was linear. However, the GUM was prone to under- or double-estimation of uncertainty components, whereas MCM can effectively avoid such errors and improve the accuracy and reliability of measurement uncertainty in trace blood lead detection.