基性岩超基性岩中痕量铂的催化极谱测定

本文针对基性岩超基性岩中ＳｉＯ＿２，Ａｌ＿２Ｏ＿３，Ｆｅ＿２Ｏ＿３，ＭｇＯ，ＣａＯ等含量高的特点，确定了１ｍｏｌ／Ｌ盐酸—０．１ｇ／Ｌ硫酸肼—３×１０￣（－３）ｍｏｌ／Ｌ甲醛底液测定痕量铂的体系，通过控制温度与改进熔矿方法，增强了体系稳定性，消除了ＳｉＯ＿２等的干扰。用于铜镍矿、铬铁矿和硅酸盐管理样的测定，结果符合要求。     

对碘偶氮氯膦与铅显色反应及其应用

研究了对碘偶氮氯膦（ＣＰＡ－ｐＩ）与Ｐｂ￣２＋的显色反应。在ｐＨ５．８的（ＣＨ＿２）＿６Ｎ。－ＮＯ＿３缓冲介质中，Ｐｂ￣２＋与ＣＰＡ－ｐｌ形成１：２的蓝绿色配合物，在６７５ｎｍ处测定配合物的吸光度，其表现摩尔吸光系数为２．４７×１０￣４Ｌ．ｍｏｌ￣－１·ｃｍ￣－１Ｐｂ￣２＋浓度在０～１．１６×１０￣－５ｍｏｌ／Ｌ即０～２．４μｍｌ）符合比尔定律。试验了２０余种共存离子的影响，经共沉淀结合巯基棉分离预处理试样溶液后，测定了硫精砂中微量Ｐｂ的含量。     

以苄基三乙基氯化铵为增敏剂催化光度法测定痕量铁

在增敏剂苄基三乙基氯化铵存在下,Fe(Ⅲ)对H2O2氧化溴甲酚绿具有催化作用,据此建立了一种测定痕量Fe(Ⅲ)的新方法。考察该反应的最佳条件,测定反应动力学参数。催化反应的表观活化能Ea为61.14 kJ/mol。方法的检出限为2.8×10-8g/L,线性范围0~600μg/L。用于河水、自来水等样品中铁的测定结果满意,相对标准偏差(RSD,n=6)小于5%。     

砷的野外快速分析方法——氢化物发生-光导分光光度法

考察了在野外工作条件下，砷氢化物发生的各种影响因素，对氢化物发生-新银盐光度法测定砷的样品分解方法进行了简化和改进，配合自行研制的光导分光光度计，实现了砷的野外快速测定。样品经王水封闭溶解后，加入混合试剂以消除干扰，在调整酸度后，加入硼氢化钾将砷还原，呈AsH3选出，使硝酸银还原成胶体银，用光导分光光度计进行测定。方法检出限（3s）为0.20μg／g，加标回收率为92．0％～108％。方法经水系沉积物国家一级标准物质验证，分析结果与标准值相符，11次测定的相对标准偏差（RSD）小于10％。     

Spectrophotometric Determination of Vanadium in Carbonaceous Shales (Stone Coal Ores) Using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol

A selective and sensitive spectrophotometric method has been developed for determining the total amount of vanadium in carbonaceous shales (stone coal ores). The method is based on the reaction of vanadium(V) with the chromophore reagent 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) in the presence of hydrogen peroxide. In a 0.072 mol l⁻¹ sulfuric acid medium, 5-Br-PADAP reacts with vanadium(V) to form a red-violet complex with a maximum absorption peak at 596 nm with an apparent molar absorption coefficient of the complex of 8.45 × 10⁴ l mol⁻¹ cm⁻¹. Beer's law was obeyed in the range 0–25 μg vanadium in 25 ml of solution, with a correlation coefficient of 0.9995. Interferences due to various non-target ions were also investigated and high quantities of other common inorganic ions were tolerable. The method involved the dissolution of the ore sample by Na₂O₂ fusion, followed by filtering of the alkali solution after which Fe(III), Cu(II), Ni(II) and Co(II) etc. were effectively separated from the solution by precipitation in a NaOH solution. Selectivity was increased with the use of EDTA as a masking agent. The vanadium in ore samples was determined with a relative deviation (RSD) between 0.20 and 0.76%, and has been successfully applied to the determination of vanadium-bearing stone coal ores. The results indicated that the accuracy of 5-Br-PADAP spectrophotometry is comparable with the ICP-AES method. The characteristics of the method, i.e., simplicity, selectivity, sensitivity and rapid calibration, make it specially suitable for routine analysis.     

碘化钾-甲基异丁基甲酮萃取-火焰原子吸收分光光度法连续测定地球化学样品中痕量银镉铊

研究了碘化钾-甲基异丁基甲酮（KI—MIBK）萃取-火焰原子吸收分光光度法连续测定地球化学样品中痕量银、镉和铊的主要条件。通过对火焰原子吸收分光光度计气路控制系统及雾化器的改进，较大地改善了萃取-火焰原子吸收分光光度法测定银、镉和铊的稳定性和灵敏度。选择萃取酸度为1．2mol／L HCl、水相和有机相体积配比为3：1～4：1，方法精密度（RSD，n=12）为Ag4．5％～9．6％、Cd1．5％～7．9％、T14．5％～5．4％，检出限（3s）为Ag0．004μg/g、Cd0．007μg／g、T10．011μg/g，符合多目标地球化学调查样品测试及质量监控要求。用国家一级标准物质和密码组合标准物质进行验证，测试结果令人满意。     

Photographic spectrophotometry of selected bright B and Be Stars

Coudé spectra taken in the red region of 49 bright B and Be stars were examined for the behaviour of Hα and the He I λλ 5876 and 6678 line profiles. 51 per cent of the stars were found to show Hα emission to some degree and 22 per cent showed helium emission. Evidence is presented for the existence of drastic changes in the line profile and the radial velocity in some of the stars on a time scale of fractions of a day. Visiting Astronomer, Kitt Peak National Observatory and Cerro Tololo Inter-American Observatory, operated by the Association of Universities for Research in Astronomy, under contract with the National Science Foundation.     

中国近海海水紫外吸收及直接用于测定海水COD

为探讨海水水质监测的简便可行方法,对渤海、北黄海、胶州湾、东海、长江口、南海及珠江口几百个海水样品紫外扫描发现,不同海区海水紫外吸收约在200～220nm之间。其中渤海、北黄海与胶州湾海水样品在208～210nm之间,而东海、长江口、南海及珠江口水样在205nm附近。海水紫外吸收吸光度与高锰酸钾法测COD值之间具有良好的线性关系。所以提出了用紫外分光光度法测定海水COD值的方法,发现紫外分光光度法与碱性高锰酸钾法测定海水COD值无显著性差异,可以满足快速监测的需要。     

纳米Cu2O/珍珠贝壳复合材料的光催化杀菌机理研究

研究了纳米 Cu2O/珍珠贝壳复合光催化材料对嗜水气单胞菌、副溶血弧菌、鳗弧菌和溶藻胶弧菌的杀菌效果,并考察了材料浓度、光源强度、作用时间等因素对杀菌作用的影响.结果表明,该复合材料对四种病原菌均具有较强的杀灭能力,复合材料浓度为100 mg/L时,无论在紫外光还是太阳光下照射2 h,杀菌率均达到100%; Fe (phen)32+光度法验证了复合材料溶液在光照过程中产生了具有强氧化活性的自由基.     

Development of an Analytical Method for the Determination of Trace Lead in Lake Water Samples by Flame Atomic Absorption Spectrophotometry after Vortex Assisted-Stearic Acid Coated Magnetic Nanoparticle Based Extraction

In the present study, a method is proposed for the determination of lead at trace levels by slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS) after preconcentration with stearic acid coated magnetic nanoparticle-based dispersive solid phase extraction (SA-MNP-DSPE). The slotted quartz tube (SQT) is used to enhance the analyte atom residence time in the light path. Stearic acid coated magnetic iron oxide (Fe₃O₄) nanoparticles, which can be easily collected with an external magnet, are used as adsorbent in the extraction process. The limit of detection (LOD) and the limit of quantitation (LOQ) values of the proposed method are obtained as 0.90 and 2.9 µg L⁻¹, respectively. The method allows high repeatability in a wide linear range between 5.0 and 250 µg L⁻¹, and the relative standard deviation for six replicates is 5.8%. The detection power is enhanced by about 77-fold compared to the regular flame atomic absorption spectrophotometry (FAAS) system. The method is validated by recovery experiments to four different lake water samples. After the spiking tests, good recovery results are calculated between 97% and 106%. These results show that lead can be detected at low levels in lake water samples with high sensitivity, accuracy, and precision.