[Interlaboratory comparison for determination of lead in drinking water].

OBJECTIVE: To analyze and evaluate the testing capability of lead in drinking water in the laboratories of the provincial and municipal centers for disease control and prevention across the country by implementing the interlaboratory comparison project. METHODS: The preparation method of the secondary standard materials were used as the reference for the sample preparation in the interlaboratory comparison project. The homogeneity and stability of the samples and short-term stability for simulated transportation were tested by single factor analysis of variance(ANOVA) and mean consistency test(t test). On top of using the kernel density estimation to test the distribution of laboratory test result, we adopted a robust statistical method to analyze the laboratory test result and used Z-score to evaluate the testing ability of each participating laboratory. RESULTS: A total of 448 laboratories throughout the country participated in the proficiency testing program.341 laboratories(76.1%) of participating laboratories, obtained satisfactory result. Results provided by 28 laboratories(6.3%) of total participating laboratories, were found suspicious in their capacities. Finally, there were 79 laboratories(17.6%) of total participating laboratories, with result found to be outliers. CONCLUSION: The statistical result of the interlaboratory comparison project show that the testing capability of lead in drinking water has been ranked as satisfactory in the laboratories of the provincial and municipal centers for disease control and prevention across the country, and the testing capability of a small number of laboratories requires further improvement.

[Proficiency test for determination of bromate in drinking water].

OBJECTIVE: To evaluate the capacity of national laboratories for determination of bromate in drinking water using Proficiency Testing Program. METHODS: The preparation method of the Secondary Standard Materials were used as the reference for the sample preparation in this Proficiency Testing Program. The homogeneity and stability of the samples and short-term stability for simulated transportation were tested by Single Factor Analysis of Variance(ANOVA) and Linear Regression and Mean consistency test. The result provided by participant laboratories were analyzed by robust statistics and assessed using the Z-score. RESULTS: A total of 369 laboratories throughout the country participated in the Proficiency Testing Program. 341 laboratories, or 92. 4% of total participating laboratories, obtained satisfactory result. Results provided by 8 laboratories, or 2. 2% of total participating laboratories, were found to suggest doubts in their capacities. Finally, there were 20 laboratories, constituting 5. 4% of total participating laboratories, with result that were found to be outliers. CONCLUSION: The capacity of national laboratories for determination of bromate in drinking water has been ranked as satisfactory according to statistical analysis of the Proficiency Testing Program result. Only a small portion of the participants require further improvement in their capacities.

[Proficiency test for determination of iron in drinking water].

OBJECTIVE: To evaluate the capacity of national laboratories for determination of iron in drinking water using Proficiency Testing Program. METHODS: The preparation method of the Secondary Standard Materials were used as the reference for the sample preparation in this Proficiency Testing Program. The homogeneity and stability of the samples and short-term stability for simulated transportation were tested by Single Factor Analysis of Variance(ANOVA) and Linear Regression and Mean consistency test. The result provided by participant laboratories were analyzed by robust statistics and assessed using the Z-score. RESULTS: A total of 1010 laboratories throughout the country participated in the Proficiency Testing Program. 928 laboratories, or 91. 9% of total participating laboratories, obtained satisfactory result. Results provided by 19 laboratories, or 1. 9% of total participating laboratories, were found to suggest doubts in their capacities. Finally, there were 63 laboratories, constituting 6. 2% of total participating laboratories, with result that were found to be outliers. CONCLUSION: The capacity of national laboratories for determination of iron in drinking water has been ranked as satisfactory according to statistical analysis of the Proficiency Testing Program result. Only a small portion of the participants require further improvement in their capacities.

[Proficiency test for determination of chlorate in drinking water].

OBJECTIVE: To evaluate the capacity of national laboratories for determination of chlorate in drinking water using Proficiency Testing Program. METHODS: The preparation method of the Secondary Standard Materials were used as the reference for the sample preparation in this Proficiency Testing Program. The homogeneity and stability of the samples and short-term stability for simulated transportation were tested by Single Factor Analysis of Variance(ANOVA) and Linear Regression and Mean consistency test. The result provided by participant laboratories were analyzed by robust statistics and assessed using the Z-score. RESULTS: A total of 327 laboratories throughout the country participated in the Proficiency Testing Program. 307 laboratories, or 93. 9% of total participating laboratories, obtained satisfactory result. Results provided by 5 laboratories, or 1. 5% of total participating laboratories, were found to suggest doubts in their capacities. Finally, there were 15 laboratories, constituting 4. 6% of total participating laboratories, with result that were found to be outliers. CONCLUSION: The capacity of national laboratories for determination of chlorate in drinking water has been ranked as satisfactory according to statistical analysis of the Proficiency Testing Program result. Only a small portion of the participants require further improvement in their capacities.

[Proficiency test for determination of anion synthetic detergent in drinking water].

OBJECTIVE: To evaluate the capacity of national laboratories for determination of anion synthetic detergent in drinking water using Proficiency Testing Program. METHODS: The preparation method of the Secondary Standard Materials were used as the reference for the sample preparation in this Proficiency Testing Program. The homogeneity and stability of the samples and short-term stability for simulated transportation were tested by Single Factor Analysis of Variance(ANOVA) and Linear Regression and Mean consistency test. The result provided by participant laboratories were analyzed by robust statistics and assessed using the Z-score. RESULTS: A total of 723 laboratories throughout the country participated in the Proficiency Testing Program. 668 laboratories, or 92. 4% of total participating laboratories, obtained satisfactory result. Results provided by 15 laboratories, or 2. 1% of total participating laboratories, were found to suggest doubts in their capacities. Finally, there were 40 laboratories, constituting 5. 5% of total participating laboratories, with result that were found to be outliers. CONCLUSION: The capacity of national laboratories for determination of anion synthetic detergent in drinking water has been ranked as satisfactory according to statistical analysis of the Proficiency Testing Program result. Only a small portion of the participants require further improvement in their capacities.

[Proficiency test for determination of fluoride in drinking water].

OBJECTIVE: To evaluate the capacity of national laboratories for determination of fluoride in drinking water using proficiency testing program. METHODS: The preparation method of the secondary standard materials were used as the reference for the sample preparation in this proficiency testing program. The homogeneity and stability of the samples were tested by single factor analysis of variance( ANOVA) and linear regression. The results provided by participant laboratories were analyzed by robust statistics and assessed using the Z-score. RESULTS: A total of 985 laboratories throughout the country participated in the proficiency testing program. 910 laboratories, or92. 4% of total participating laboratories, obtained satisfactory result. Results provided by26 laboratories, or 2. 6% of total participating laboratories, were found to suggest doubts in their capacities. Finally, there were 49 laboratories, constituting 5. 0% of total participating laboratories, with results that were found to be outliers. CONCLUSION: The capacity of national laboratories for determination of fluoride in drinking water has been ranked as satisfactory according to statistical analysis of the proficiency testing program results. Only a small portion of the participants require further improvement in their capacities.

[Proficiency test for determination of tribromomethane in drinking water].

OBJECTIVE: To evaluate the capacity of national laboratories for determination of tribromomethane in drinking water using proficiency testing program. METHODS: The preparation method of the secondary standard materials were used as the reference for the sample preparation in this proficiency testing program. The homogeneity and stability of the samples were tested by single factor analysis of variance( ANOVA) and linear regression. The results provided by participant laboratories were analyzed by robust statistics and assessed using the Z-score. RESULTS: A total of 352 laboratories throughout the country participated in the proficiency testing program. 317 laboratories, or 90. 0% of total participating laboratories, obtained satisfactory results. Results provided by 14 laboratories, or 4. 0% of total participating laboratories, were found to suggest doubts in their capacities. Finally, there were 21 laboratories, constituting 6. 0% of total participating laboratories, with results that were found to be outliers. CONCLUSION: The capacity of national laboratories for determination of tribromomethane in drinking water has been ranked as satisfactory according to statistical analysis of the proficiency testing program results. Only a small portion of the participants require further improvement in their capacities.

[Study on proficiency test for determination of aluminum in drinking water in 2016].

OBJECTIVE: To evaluate the capacity of national laboratories for determination of aluminum in drinking water using proficiency testing program. METHODS: The preparation method of the secondary standard materials were used as the reference for the sample preparation in this proficiency testing program. The homogeneity and stability of the samples were tested by single factor analysis of variance( ANOVA) and linear regression. The result provided by participant laboratories were analyzed by robust statistics and assessed using the Z-score. RESULTS: 590 laboratories throughout the country participated in the proficiency testing program. 533 laboratories, or 90. 3% of total participating laboratories, obtained satisfactory result. Results provided by 7 laboratories, or 1. 2% of total participating laboratories, were found to suggest doubts in their capacities. Finally, there were 50 laboratories, constituting 7. 6% of total participating laboratories, with result that were found to be outliers. CONCLUSION: The capacity of national laboratories for determination of aluminum in drinking water has been ranked as satisfactory according to statistical analysis of the proficiency testing program result. Only a small portion of the participants require further improvement in their capacities.

[Analysis results of proficiency test for determination of lindane in drinking water in 2016].

OBJECTIVE: To evaluate the capacity of national laboratories for determination of lindane in drinking water using proficiency testing program. METHODS: The preparation method of the secondary standard materials were used as the reference for the sample preparation in this proficiency testing program. The homogeneity and stability of the samples were tested by single factor analysis of variance( ANOVA) and linear regression. The result provided by participant laboratories were analyzed by robust statistics and assessed using the Z-score. RESULTS: 309 laboratories throughout the country participated in the proficiency testing program. 286 laboratories, or 92. 6% of total participating laboratories, obtained satisfactory result. Results provided by 10 laboratories, or 3. 2% of total participating laboratories, were found to suggest doubts in their capacities. Finally, there were 13 laboratories, constituting 4. 2% of total participating laboratories, with result that were found to be outliers. CONCLUSION: The capacity of national laboratories for determination of lindane in drinking water has been ranked as satisfactory according to statistical analysis of the proficiency testing program result. Only a small portion of the participants require further improvement in their capacities.

[Proficiency test for determination of benzene in drinking water].

OBJECTIVE: To evaluate the capacity of national laboratories for determination of benzene in drinking water using Proficiency Testing Program. METHODS: The preparation methods of the Secondary Standard Materials were used as the reference for the sample preparation in this Proficiency Testing Program. The homogeneity and stability of the samples were tested by Single Factor Analysis of Variance( ANOVA) and Linear Regression. The results provided by participant laboratories were analyzed by robust statistics and assessed using the Z-score. RESULTS: The total of 242 laboratories throughout the country participated in the Proficiency Testing Program. The total of 220 laboratories, or 90. 9% of total participating laboratories, obtained satisfactory results. Results provided by 9 laboratories, or 3. 7% of total participating laboratories, were found to suggest doubts in their capacities. Finally, there were 13 laboratories, constituting 5. 4% of total participating laboratories, with results that were found to be outliers. CONCLUSION: The capacity of national laboratories for determination of benzene in drinking water has been ranked as satisfactory according to statistical analysis of the Proficiency Testing Program results. Only a small portion of the participants require further improvement in their capacities.

[Evaluation on the capability of testing carbon tetrachloride, benzene, methylbenzene, dimethylbenzene, p' p-DDT of the provincial centers for disease control and prevention].

OBJECTIVE: To evaluate the Centers of Disease Control and Prevention's (CDC) provincial divisions' capabilities of detectingconcentrations of organic parameters such as carbon tetrachloride, benzene, methylbenzene, dimethylbenzene and pesticide parameter of p' p-DDT in drinking water, by adopting a quality control assessment methodology of interlaboratory comparison. METHODS: All laboratories had been divided into 2 groups, each of which contained aboutl6 laboratories. Organic concentrations and pesticide concentrations were assigned to 2 sample groups. Testing capabilities of the laboratories were evaluated through the use of robust statistical methods. RESULTS: Thirty CDC provincial divisions, including municipalities under the central government and in autonomous regions, participated in this interlaboratory comparison. Twenty laboratories obtained positive results in all parameters, accounting for 66.7%. Eight laboratories' results were suspicious, accounting for 26.7%. Finally, 2 laboratories produced outliers, accounting for 6.7%. CONCLUSIONS: The majority of provincial CDC participants in this interlaboratory comparison are capable of testing the concentrations of organic parameterssuch as carbon tetrachloride, benzene, and methylbenzene, dimethyl benzene, and pesticide concentrations of p' p-DDT in drinking water.

[Evaluation on the capability of testing total dissolved solids of the provincial centers for disease control and prevention].

OBJECTIVE: To evaluate the Centers of Disease Control and Prevention's (CDC) provincial divisions' capabilities of detecting concentrations of organoleptic and physical parameter of total dissolved solids by adopging a quality control assessment methodology of interlaboratory comparison. METHODS: All laboratories had been divided into 2 groups of which contained 16 laboratories. Total dissolvedsolids' concentrations were assigned to 2 sample groups. Testing capabilities of the laboratories were evaluated through the use of robust statistical methods. RESULTS: Thirty-two CDC provincial divisions, including municipalities under the central government and in autonomous regions, participated in this interlaboratory comparison. Thirty laboratories obtained positive results, accounting for 93. 8%. Two laboratories' results were suspicious, accounting for 6. 2%. Finally, no laboratories produced outliers. CONCLUSIONS: The majority of provincial CDC participants in this interlaboratory comparison are capable of testing the concentrations of total dissolvedsolidsin drinking water.