Comparison of various sensitive and selective spectrophotometric assays of environmental cyanide

A simple approach was carried out to study the effects of various parameters on high performance liquid chromatography (HPLC) performance of microcystin-LR (MC-LR) analysis in samples from some reservoirs and rivers in Taiwan under simulation conditions. Nature of column and its packing affected the instrument sensitivity. Varied column length indicated the longer column enhanced (C18, 5 μm, 4.6 × 150 mm) HPLC performance. Studies on mobile phase found that ratio and concentration of the mobile phase gradient greatly influenced the peak shape, retention time, and optimal conditions of mobile phase were set at acetonitrile and 0.01M ammonium acetate (30:70). Different compounds were added to mobile phase and their contribution to HPLC spectra was reported. Detection limits were carefully measured and reported. These investigations provide simple and important information that may be applied to HPLC performance for microcystin analysis from natural water systems.     

Spectrophotometry determination of Congo red in river water samples using nanosilver

A spectrophotometric procedure for the anionic diazo dye Congo red was proposed based on nanosilver catalyzed oxidation by potassium iodate in a hydrochloric acid medium. The calibration graph is linear for 0.8–240?mg?L^?1, and the detection limit is 0.6?mg?L^?1. Most foreign ions do not interfere with the determination, except for Cu(II), Fe(III), and Cr(VI). The interferences of Cu(II) and Fe(III) could be eliminated by masking with ethylene diamine tetraacetate, and that of Cr(VI) by reducing to Cr(III) with ascorbic acid. The typical features of this procedure are that it is sensitive for Congo red, and the determination could be carried out at room temperature. It had been used for the determination of Congo red in the Ganjnameh river water sample.     

紫外法测定石油类的标准物质比对分析

对紫外法测定地表水中石油类污染物的三个厂家标准物质的吸收波长、校准曲线、质谱和测定结果进行了对比分析.试验结果表明,不同厂家标准物质的配制成分不同,标准曲线差异大,导致测定结果偏差较大,数据可比性和准确性较差,对石油类监测带来了困扰,建议国家在市售正已烷体系适用于紫外分光光度法测定的有证标准物质的选用上做出明确规定.     

铬菁R显色分光光度法测定水中铝

以铬菁R为显色剂、氯代十六烷基吡啶和曲力通X-100为双组分增敏剂,建立了测定水中Al³⁺的铬菁R显色分光光度法,并对实验条件进行了优化。实验结果表明：双组分增敏剂的引入,在提高测定灵敏度的同时也增强了测定选择性;在Al³⁺质量浓度为0.030~0.32 mg/L的范围内,校准曲线的线性关系良好,方法检出限为0.10 mg/L;精密度测定（n=6）的相对标准偏差小于3%,实际样品测定的加标回收率为97.8%~101%。本方法降低了试剂空白值,具有灵敏度高、精密度好、测定范围宽的特点,技术指标优于所有现行国家标准测定水中Al³⁺的分光光度法。     

碱性过硫酸钾消解紫外分光光度法测定水中微量总氮影响因素分析

采用国标《碱性过硫酸钾消解紫外分光光度法》（ HJ 636-2012）测定水中总氮（ TN）,虽然实验步骤简单,但影响因素较多,需严格控制实验条件。本文针对含量在方法检出限0．05 mg/L附近的微量总氮水样,从实验用水、器皿的处置、试剂的配制与存放、消解样品的制作与冷却时间等方面考察了总氮空白值的控制、校准曲线的选取等影响因素,优化了实验条件,结果令人满意。     

湿式消解法对冷原子吸收测定生物样品中汞产生的干扰

用不同的湿式消解法对多种生物样品的进行消解测定,分析了实验的干扰因素,并推荐了比较适宜的消解方法。     

分光光度法测定废水中草甘膦的探讨

探讨了亚硝基衍生化紫外分光光度法测定废水中草甘膦的适用性,考察了硫酸加入体积对亚硝化反应的影响,提出应根据样品碱度调整硫酸用量。方法与高效液相色谱法测定值的重现性较好,应用于实际废水中草甘膦测定的加标回收率为95%～105%,平行测定的RSD≤1.3%,检出限为0.069 mg/L,检测上限为50.0 mg/L,废水中可能存在的伯胺和叔胺类物质对测定无明显干扰。     

4-氨基安替比林直接光度法测定污水中高浓度挥发酚

以50.00 mg/L的苯酚标准溶液配制校准曲线系列,按4-氨基安替比林直接光度法加入试剂进行显色反应,于波长510 nm,用5 mm比色皿测定溶液的吸光度,可将测定上限扩大到12.5 mg/L。高浓度的含酚污水往往直接或稀释较少倍数就能测定。本法的检出限为0.06 mg/L,显色体系可稳定60 min,RSD<4%,加标回收率为96.8%~102.5%,与标准法的测定结果无显著性差异。     

浊点萃取-原子吸收光谱法测定水和花粉中痕量铜、铅、镉

以氢氧化钠为沉淀剂,依据Triton X-114的浊点现象分离沉淀,沉淀在浓盐酸作用下溶解,用原子吸收光谱法测定样品中痕量铜、铅、镉。通过试验优化测定条件,使该方法在0 mg/L~6.00 mg/L范围内线性良好,3种元素的方法检出限分别为0.028μg/L、0.006μg/L、0.028μg/L。将该方法用于水样、花粉中痕量铜、铅、镉的测定,RSD为2.8%~7.9%,加标回收率为92.0%~106%。     

微波消解光度法测定COD及综合效益分析

微波密闭消解水样(10mL)15min,然后用分光光度法测定消解液中Cr3+的浓度,通过作纯物质标准系列的重复实验,对其标准曲线的相关性、斜率、截距进行检验。通过实际水样进行应用可行性及综合效益分析,研究结果表明:微波消解光度法所测COD值与标准法测定值有很好的一致性,准确度较好;在单次测试中,本法测试成本约为标准法的50%,其潜在的二次污染比标准法低。因此,微波消解光度法具有良好的应用前景。