RESUMO
Objective To understand and improve the laboratory detection capacity of water manganese in testing organizations of Shaanxi Province． Methods The self-made manganese capacity testing samples were used as the reference in this proficiency testing program. The homogeneity of the samples was tested by single factor analysis of variance. The t-test method was used to evaluate the stability of the samples. The results of manganese in water provided by participant laboratories were analyzed by the robust statistical technique Z-score. Results A total of 136 laboratories participated in the proficiency testing program throughout the province. Among them, 129 laboratories (including retest laboratory) or 94.85% of total participating laboratories obtained satisfactory results. Conclusion The water quality monitoring agencies of our province had shown a strong detection capability for the determination of metal elements in drinking water, which ensures to provide safe water supply to the residents in Shaanxi Province.