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。     

萃取分光光度法测定水和硫酸中的硒

本文提出一种测定硒的分光光度法。在酸性介质中，四价硒氧化Ｉ成为Ｉ３，Ｉ３－和结晶紫形成的离子缔合物用二甲苯萃取，进行分光光度测定。硒的检出限是０．０５μｇ／ｍＬ。用磷酸和ＥＤＴＡ消除Ｆｅ＾３＋，Ｐｂ＾２＋，Ｈｇ＾２＋等离子的干扰影响。本法可不和硫酸中四价硒。