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In CH3COONa-HCl buffer solution, ClO2- oxidizes excess I- to generate I3-, and I3- forms complex particles with positively charged methylene blue under electrostatic attraction, which enhances the resonance scattering intensity of the system. Based on this principle, a new method for the determination of trace NaClO2 in water by resonance scattering spectroscopy was established.The measurement conditions of this method were optimized to improve the resonance scattering intensity. The optimal dosage of CH3COONa-HCl buffer solution, KI solution, and methylene blue solution, as well as the optimal reaction time and measurement wavelength, were obtained during the measurement. Under the optimal conditions, the resonance scattering intensity increased with the increase of ClO2- mass concentration in the range of 0.018 2-0.364 0 mg/L, which showed a good linear relationship with a detection limit of 0.004 8 mg/L. When this method was used to determine the content of chlorite in groundwater, the relative standard deviation of the measurement results was 1.5%-2.9%, and the recovery rate was 96%-99%.

Mental illness patients due to impairment in the daily function, lack of and need most the refined care of social relationship. This is the original purpose of metal medical treatment with the idea of deinstitutionalization and holistic health care, also the precondition of the community treatment and community care. With this understanding, continuous and complex treatment phases for severe patient should be planned in the mandatory hospitalization and later community treatment. Offering to severe patient as regards their need of mental treatment and care, therefore to adapt to living and overcome their barrier of taking treatment, is not only for the community security, but as a beginning of active realization of their metal care and health right. [ABSTRACT FROM AUTHOR]

In pH 7.0 tris-HCl buffer solutions and in the presence of 0.017 mol x L(-1) NaCl, herring sperm DNA was combined with gold nanoparticles in size of 10 nm to form stable complex, and the NaCl did not cause the aggregation of the gold nanoparticles. Upon addition of Hg2+, that reacted with DNA to form more stable complex of Hg(2+)-DNA, and the gold nanoparticles aggregated to from larger nanogold clusters that led to considerable enhancement of the resonance scattering intensity at 572 nm enhanced considerably. The effect of GN concentration, DNA concentration, NaCl concentration, incubation time, and temperature, and ultrasonic irradiation was considered respectively, the conditions of 3.87 microg x mL(-1) GN, 11.7 microg x mL(-1) DNA, pH 7.0 Tris-HCl buffer solutions, 17 mmol x L(-1) NaCl, and incubation 10 min at 37 degrees C under the ultrasonic irradiation were chosen for use. Under the conditions, the enhanced resonance scattering intensity at 572 nm was linear to the Hg2+ concentration in the range of 3.3-3 333.3 nmol x L(-1), with regress equation of delta572 nm = 0.019c+5.0, coefficient of 0.999 1, and a detection limit of 2.5 nmol x L(-1) Hg2+. Results of interference tests showed that 30 micromol x L(-1) Mn2+, 33 micromol x L(-1) Mg2+ and Zn2+, 100 micromol x L(-1) Cd2+, 200 micromol x L(-1) Fe3+, and 420 micromol x L(-1) Mo6+, Pb2+ and Cu2+ did not interfered with the determination of 0.33 micromol x L(-1) Hg2+. That is, this resonance scattering spectral assay is of good selectivity. This assay was applied to the detection of Hg(II) in water sample, with a relative standard deviation of 5.1%, and the results were in agreement with that of the cool vapor atomic absorption spectrophotometry.