Flow injection analysis methods for determination of diffusion coefficients

Two flow injection analyses (FIA) methods for the determination of diffusion coefficients in a straight single tube FIA system were developed. Based on the analytical solution of the convection-diffusion equation, linear relationships of the logarithmic values of the dispersion coefficient (D) and the half-peak width (W_1/2) with the diffusion coefficient (D_m) were obtained. Experiments were designed to verify these methods. For example, for potassium hexacyanoferrate (III) a D_m value of 0.72 × 10⁵ cm² s⁻¹ was found versus a literature value of 0.76 × 10⁵ cm² s⁻¹ (error, 5%). For potassium hexacyanoferrate (II) a D_m value of 0.67 × 10⁵ cm² s⁻¹ was obtained versus a literature value of 0.63 × 10⁵ cm² s⁻¹ (error, 6%). The diffusion coefficients of some important biomedical compounds, such as dopamine, epinephrine, norepinephrine and ascorbic acid, were then determined. The values of 10⁵ D_m/cm² s⁻¹ are 0.60 ± 0.03, 0.44 ± 0.02, 0.60 ± 0.01 and 0.68 ± 0.06, respectively.     

微量元素铜、锰与精神分裂症

应用等离子体发射光谱法（ＩＣＰ－ＡＥＳ）对精神分裂症急性期男病人４８例，女病人３０例和慢性期男病人５０例，女病人３０例，检测头发中Ｚｎ、Ｆｅ、Ｃｕ、Ｃａ、Ｍｎ５种元素，并与１５８名男女正常人作对照，发现无论是急性期还是慢性期，男女病人的Ｃｕ、Ｍｎ两元素的含量，均显著低于正常人（Ｐ＜０．０５～０．００１）．     

激光解吸电离质谱法分析富勒烯

论述了用激光解吸电离谱法分析富勒烯。因在电离过程中富勒分子不发生裂解，因此这种方法可直接用于富勒烯混合物的分析而勿需任何预分离。还给出了用本法分析较大、较稳定富勒烯分子的质谱图。     

Measurements of HO2 uptake coefficient on aqueous (NH4)2SO4 aerosol using aerosol flow tube with LIF system

The γ(HO₂) was elevated with increase of Cu(II) concentrations in aqueous (NH₄)₂SO₄ aerosol. The threshold of Cu(II) concentration was 10^-3 mol/L for the dramatic increase of γ(HO₂) to 0.1, suggesting sensitive γ(HO₂) value to concentration of transition metal ions in aerosol.