Reference Intervals of Serum Sodium, Potassium, and Chlorine in Chinese Han Population and Comparison of Two ISE Methods.

BACKGROUND: Currently there are no reference intervals (RIs) of sodium (Na), potassium (K), and chlorine (Cl) on Chinese population. Two kinds of ion-selective electrode (ISE) methods were commonly used to determine K, Na, and Cl levels in China, the difference between these two methods needs to be evaluated. METHODS: A total of 4,524 healthy participants (1,916 males and 2,608 females) between 20-79 years old from six cities in China were selected by strict criteria. Serum K, Na, and CL were tested on Roche Modular analyzers in six assigned laboratories. According to EP-9A2, using Roche Modular analyzer (indirect ISE) as comparative method, Olympus AU 5400 analyzer (indirect ISE) and Johnson&Johnson Fusion 5.1 analyzer (direct ISE) were evaluated. RESULTS: In Chinese population, the RIs for K, Na, and CL are 3.6-5.2, 136-146, and 99-110 mmol/l, respectively. Compared to the Roche indirect ISE method, Johnson direct ISE method showed a positive bias; and Olympus indirect ISE method just showed a very slight bias. CONCLUSION: The RIs of K, Na, and Cl of Han Chinese healthy adult population were found to be smaller than those provided by the manufacturer. By a criteria of biological variations for CV, the differences of Na and K between Roche analyzer and Johnson analyzer were not acceptable for clinical application, while the differences of Na, K, and Cl between Roche and Olympus analyzers were acceptable for clinical application.

Hand-held water fluoride analysis: An accessible caries prevention tool for dental professionals.

This study sought to compare the relative accuracy of a commercially available hand-held water fluoride analysis unit with a standard laboratory bench-top fluoride-specific electrode/millivoltmeter apparatus, with the goal of identifying possible practical applications of the hand-held unit for preventive dentistry. The units analyzed identical gravimetrically prepared fluoride solutions ranging from 0.1 to 4.0 ppm. The average difference between the measurements from the hand-held unit and the nominal values of the fluoride solutions was 0.011 ppm (SD = 0.068), and the average difference between the hand-held unit's measurements and the bench-top unit's measurements was 0.030 ppm (SD = 0.115). T-test analysis demonstrated no statistical difference between measurements from the hand-held unit with either the nominal values of the fluoride solutions or the bench-top unit's measurements. Results indicate that the hand-held water fluoride analysis unit has an appropriate level of accuracy for the measurement of fluoride levels in drinking water samples by dental professionals.