测定水体中镉的维多利亚艳蓝BO-碘分光光度法

目的建立一种测定河水中痕量镉的新方法。方法用巯基棉富集分离河水中痕量镉,在含4×10^(-3)％乳化剂OP的H3PO4-NaH2PO4溶液中,维多利亚艳蓝BO与[CdI4]2-反应生成离子缔合物,溶液颜色由黄色变为艳蓝色,分光光度法测定河水中痕量镉。结果镉富集50倍,离子缔合物表观摩尔吸光系数ε=2.79×10~5L/(mol·em),线性范围2-100μg/L,回收率96.2％-98.6％,相对标准偏差2.5％。结论方法准确、灵敏,可应用于水体中痕量镉的测定。

K系数-多波长线性回归分光光度法同时测定原油中的铁、钴、镍

提出一种同时测定三组份的新方法 ,即K系数 -多波长线性回归分光光度法 ,用于同时测定原油中的铁、钴、镍。以OP -5-Br-PADAP为显色体系 ,控制 pH为 4 0以消除干扰。相对标准偏差在 1 1 %～ 5 3%之间。该方法简便、准确 ,灵敏度高。

城镇污泥中总磷测定条件的优化选择——过硫酸钾消解后钼酸铵分光光度法

依据水中总磷的测定原理,通过过硫酸钾消解后钼酸铵分光光度法对污泥中的总磷进行测定,并对过硫酸钾消解后钼酸铵分光光度法的实验条件,包括污泥样品取样量、过硫酸钾溶液加入量和消解时间进行了优化选择。结果发现污泥样品取样量为0.1g左右(以干泥计),过硫酸钾溶液加入量为50m L,消解时间为30min的条件下,加标回收率为90%~105%。因此,优化选择的方法能满足实验室的要求,可作为城镇污泥中总磷的测定方法。

正常人群中尿碘测定价值初探

通过对人群中尿碘含量的调查,了解尿碘的正常值范围,为机体碘缺乏病的监测提供了一个可靠的监测手段.方法采用酸消化铈——砷催化分光光度法,统计检测了358例3—52岁正常人的尿碘含量,结果分析男女性别和各年龄组之间无显著性差异.

Determination of Total Flavones Content in Ceratocarpus arenarius L. by Spectrophotometry

[Objective] The aim was to establish the method for determining total flavoens content in Ceratocarpus arenarius L.[Method ] Flavonoids were extracted from C. arenarius by heating refluxing, and determined with rutin as the standard.[Result] In the range of 0.019-0.102 mg/ml, linear relationship was good （r=0.999 1）. This method had higher precision and accuracy with RSD of 0.226% and recoveries of 99.36%. The total flavones content from C. arenarius was 10.12 mg/g. [Conclusion] The method is simple and reliable, which could be used to control the quality of C. arenariu.

Propylene Polymerization Catalysts with Sulfonyl Amines as Internal Electron Donors

Three sulfonyl aliphatic amines [（R2SO2）2NR1, viz.： compound 1, in which RI=Me, and R2=Ph; compound 2, in which R1=n-Bu, and R2=CF3; and compound 3, in which RI=C8H17, and R2=CF3], have been synthesized and employed as internal electron donors （IED） for the preparation of Ziegler-Natta catalysts for the polymerization of propylene. The contents of Ti, H and C in these catalysts have been determined by elemental analysis and UV-vis spectrophotometry. The effect of the structure and dosage of the electron donor, the A1/Ti ratio and the polymerization temperature on the catalyst performance has been studied. Under optimized conditions, the catalyst with a highest activity yielded polypropylene with high isotacticity in the absence of external electron donors.

Expression Analysis of the ANS Gene in Fragaria x ananassa cv, Toyonaka

Strawberry is an economically valuable crop all over the word. Its fruits contain large amounts of polyphenol compounds, anthocyanins for instance. Anthocyanins play important roles in attracting pollinators and protecting plants from various stresses. ANS （Anthocyanidin synthase） catalyzes the conversion of leucoanthocyanidins to colored anthocyanidins. In this study, the total anthocyanins concentration at seven developmental stages of the strawberry fruit were investigated by UV spectrophotometry at 496 nm and 700 rim; and the expression levels of the Fa-ANS gene were studied by qRT-PCR. The results showed that the anthocyanins contents gradually increased along with the fruit maturation; while the expression patterns of Fa-ANS were consistent with the anthocyanins.

Investigation of the pharmacokinetics and determination of certain cephalosporins in rabbit plasma by a kinetic spectrophotometric method with the aid of chemometrics

This paper describes a kinetic spectrophotometric method for simultaneous determination of three cephalosporin antibiotics,cephradine,cefaclor and cefixime,with the aid of chemometrics. The method relies on their oxidation with KMnO4 to produce green manganate with different kinetic rates in alkaline medium. The proposed method was successfully applied to a pharmacokinetic study of three cephalosporin antibiotics in rabbit plasma via intravenous injections. The results indicated that the amount of cephradine,cefaclor and cefixime were reduced rapidly in rabbit blood,showing clear dose-dependency and the half-life of cefixime (160 min) was longer than those of cephradine (60 min) and cefaclor (60 min).