Science Letters：Evaluation of a kinetic uricase method for serum uric acid assay by predicting background absorbance of uricase reaction solution with an integrated method

A patented kinetic uricase method was evaluated for serum uric acid assay. Initial absorbance of the reaction mixture before uricase action （A0） was obtained by correcting the absorbance at 293 nm measured before the addition of uricase solution, and background absorbance （Ab） was predicted by an integrated method. Uric acid concentration in reaction solution was calculated from AA, the difference between A0 and Ab, using the absorptivity preset for uric acid. This kinetic uricase method exhibited CV〈4.3% and recovery of 100%. Lipids, bilirubin, hemoglobin, ascorbic acid, reduced glutathione and xanthine 〈0.32 mmol/L in serum had no significant effects. △A linearly responded to 1.2 to 37.5 μmol/L uric acid in reaction solution containing 15 μl serum. The slope of linear response was consistent with the absorptivity preset for uric acid while the intercept was consistent with that for serum alone. Uric acid concentrations in clinic sera by different uricase methods positively correlated to each other. By Bland-Altman analysis, this kinetic uricase method accorded with that by quantifying the total change of UV absorbance on the completion of uricase reaction. These results demonstrated that this kinetic uricase method is reliable for serum uric acid assay with enhanced resistance to both xanthine and other common errors, wider range of linear response and much lower cost.     

紫外可见分光光度法测定土壤中有效磷

以紫外可见分光光度法测定土壤中有效磷的含量,此方法操作简便,仪器常见,专一性强,准确度高及结果可靠等优点,符合测定结果和分析的技术要求.     

化学复合镀液中Al2O3微粒分散剂研究

研究用于Ni-P/Al2O3化学复合镀液的Al2O3悬浮液分散剂.将140 nm的α-Al2O3干粉与表面活性剂溶液混合,采用高速机械搅拌和超声波分散Al2O3悬浮液.通过分光光度计测定悬浮液吸光度,用PdCl2测试镀液稳定性;通过孔隙率试验和结合力试验测试化学复合镀层性能,用SEM和EDS测试镀层形貌和化学成分.试验结果表明,阴离子型表面活性剂与非离子型表面活性剂复配,对Al2O3悬浮液的分散稳定有较好的协同效果,适宜的复配分散剂组成为：20 mg/L十二烷基硫酸钠,150 mg/L Tween-80,80 mg/L聚乙二醇.用其配置2 g/L纳米Al2O3悬浮液,静置24 h后吸光度为1.595.该悬浮液配置的镀液稳定性试验时间为165 s,镀速为16.5μm/h.复合镀层中Al2O3粒子呈弥散状分布,Al2O3含量为0.77%.镀层光亮、致密.孔隙率为0.06个/cm2.结合力符合GB/T13913-92标准.该复配分散剂适应于Ni-P/Al2O3化学复合镀液.     

银纳米基比色传感法测定水样中汞离子的方法

基于银纳米粒子在盐诱导下聚集使体系颜色发生改变这一原理,建立一种生物传感方法检测水样中的汞离子.采用柠檬酸还原法合成银纳米粒子并修饰以核酸适配体,汞离子与核酸适配体结合发生变构效应导致银纳米粒子暴露在盐环境中发生聚集,使体系光谱特征峰和颜色发生明显变化.研究体系特定波长吸光度比值与汞离子浓度的变化关系.在最佳优化条件下,该比色法在质量浓度区间为0.2~50 ng/mL呈现良好线性关系,检出限为0.11 ng/mL.将该检测体系应用于汞离子类似物的检测,特异性较好.该方法对水样中汞离子的检测有一定的应用前景.     

紫外分光光度法测定麦迪霉素的含量

以紫外分光光度法测定麦迪霉素的含量。麦迪霉素在乙醇介质中于 2 3 0nm波长处测定吸光度计算含量 ,平均回收率 ( 97 2 0± 0 8) % (n =6) ,方便简便、快速、准确 ,可作为该制剂的质量控制方法。     

腺嘌呤电氧化吸附量的研究

提出一种通过常规扫速测试对吸附量进行初步估计的新方法.通过循环伏安技术对腺嘌呤在玻碳电极上的吸附现象进行了研究,对电活性质粒吸附量进行了定性判断.结果表明,弱吸附吸附量的数量级一般在10-10molcm-2.