用N-对辛基氧(代)苯甲酰苯基羟胺和苯基荧光酮萃取分光光度测定环境试样中的微量Ti(Ⅳ)

1. 前言 现在广泛应用过氧化氢法和二安替比林甲烷分光光度法测定Ti(Ⅳ)。然而,在测定环境试样中微量Ti(Ⅳ)时,必须开发灵敏度更高的分光光度分析方法。苯甲酰苯基羟胺(BPHA)及其衍生物是V(Ⅴ)的特效分光光度试剂,已众所周知。但是,BPHA在强盐酸酸性条件下也与Ti(Ⅳ)反应,生成黄色络合物而被有机溶剂萃取。利用这一反应,用BPHA及其衍生物分光光度测定Ti(Ⅳ)的报导较多。为了提高灵敏度,又进一步研究了Ti(Ⅳ)—BPHA—硫氰离子三元络合物的萃     

维多利亚蓝B与碘在水溶液中的显色反应-吸光光度法测定海产品中的碘

研究了水相中,维多利亚蓝B与碘离子(I~-)的显色反应.当磷酸浓度为1.6mol/L,聚乙烯醇为0.08％时,维多利亚蓝B与碘形成络合比为1∶3的络合物,最大吸收峰位于375nm处,表观摩尔吸光系数为1.02×10~4L/mol·cm,碘在(0～16)μg/ml范围内符合比耳定律.方法可用于海洋生物等样品中的微量碘测定,结果满意.     

火焰原子吸收分光光度法测定水中微量钙

水中微量钙虽有许多测定方法(如原子吸收法、电感耦合等离子体发射光谱分析法、离子电泳法、离子电极法和离子色谱法等直接定量法),但这些方法都易受共存离子的影响.此外,当采用这些方法测定微量钙时,需浓缩或溶剂萃取等,操作烦琐.现已研究出采用火焰原子吸收分光光度计(F-AAS)测定水中微量钙的方法.     

罗丹明3B光度法测定生物样品中微量铜

本文报导在8N硫酸介质中溴化铜与罗丹明3B形成离子缔合物可被苯萃取,表现克分子吸收系数8.9×10~4(565nm)比耳定律符合范围为0.01-0.6微克/毫升,在有机相中的多元络合物至少稳定24小时,本法选择性好,不用分离和富集可直接测定生物样中微量铜。     

氢化物发生——分光光度法连续测定砷和铋

过去氢化物发生技术多应用于单一元素的测定,我们从同一试液中测定多元素出发,开展了氢化物发生——分光光度法连续测定砷和铋的研究。微量铋的分析有铋碘络阴离子与碱性染料形成络合物的萃取光度法等。氢化物发生——分光光度法测定铋的方法也有报导,但消除干扰操作较繁。我们将铋化氢导入铁(Ⅲ)-邻菲啰啉的乙醇溶液,得到了红色的铁(Ⅱ)-邻菲啰啉,此一反应可用于铋的分光光度测定。此法锑将产生严重干扰。若将锑(砷)氧化为高价后,再于pH4.5—5.0用硼氢化钾将铋离子转变为铋化氢,此时锑(砷)离子仍留在溶液中,消除了锑对铋测定的干扰。本方法按取试样1g计,砷检出限为0.07ppm(35),铋检出限为0.08ppm(35)。应用于河流沉积物、岩矿和金属样品中砷和铋的连续测定,得到了较好结果。     

磷酸—磷酸氢二钠法测定尿、血液中的碘元素

尿、血液中碘的测定前处理方法很多，本法用磷酸—磷酸氢二钠离子强度缓冲液加抗坏血酸分解样品，无需分离，在ｐＨ２的条件下用碘离子选择电极直接浓度直读法测定尿、血液中的碘。本法检出限为１０μｇ·ｍｌ－１，标准偏差为０３５０μｇ·ｍｌ－１，精密度为３５８％，具有简便、快速等特点。     

气相分子吸收光谱法测定海水中氨氮的干扰因素识别及预处理方法研究

采用气相分子吸收光谱法测定海水样品中的氨氮,重点考察海水中共存离子对氨氮测定结果的影响规律,识别测定过程中主要的干扰因素,并提出消除干扰的预处理方法.研究结果表明,碘离子会对氨氮的测定产生负干扰,当样品中碘离子质量浓度达到0.0765 g/L时,氨氮的测定结果与标准值相比明显降低,且在碘离子质量浓度达到0.1910 g...     

催化光度法测定鸡蛋中的碘

研究了在 80～ 1 0 0℃条件下制备样品 ,利用催化光度法间接测得鸡蛋中碘的含量。在 0～ 0 .0 2 1 mg/ L内符合比耳定律 ,摩尔吸光系数达 2 .0 3× 1 0 5L.mol- 1 .cm- 1。可用于其它食品中微量碘的测定。     

萃取光度法测定碘的研究

在0.45-4.5N磷酸介质中,以甲苯萃取碘——碘离子——乙基紫缔合物,最大吸收峰位于620nm,表观摩尔吸光系数为6.67×10~4升/摩尔·厘米.0-2mg/L范围符合比尔定律,成功地应用于海洋生物和底泥中微量碘的测定,结果满意。     

双波长分光光度法同时测定叶绿素a、b

介绍了同时测定叶绿素ａ、ｂ 的双波长分光光度法。该法不进行预分离，直接测定，操作简便，结果与先分离、再以强氧化剂消解后分别测定镁离子浓度进而推算叶绿素ａ、ｂ 浓度的原子吸收法有一定可比性，本法具有进一步推广应用的价值。     

乙基橙褪色光度法测定加碘盐中微量碘（Ⅴ）

提出了在盐酸介质中，在溴化钾催化作用下，碘酸根氧化乙基橙褪色吸光光度法测定碘的新方法。结果表明，最大吸收波长为５１０ｎｍ时，碘（Ⅴ）浓度在０～１．６ｍｇ／Ｌ内呈线性关系，表观摩尔吸光系数为４．４×１０４，方法用于加碘盐中碘（Ⅴ）的测定，结果满意。     

Euro Chlor Risk Assessment for the Marine Environment Osparcom Region: North Sea - 1,1,2-Trichloroethane

This risk assessment on 1,1,2-trichloroethane (T112) was carried out specifically for the marine environment, according to the methodology laid down in the EU risk assessment Regulation (1488/94) and the Guidance Document of the EU New and Existing Substances Regulation (TGD, 1997). The study consists of the collection and evaluation of data on effects and environmental concentrations from analytical monitoring programs in large rivers and estuaries in the North Sea area. The risk is indicated by the ratio of the "predicted environmental concentrations" (PEC) and the "predicted no effect concentrations" (PNEC) for the marine aquatic environment. In total, 22 studies for fish, 45 studies for invertebrates and 9 studies for algae have been evaluated. Both acute and chronic toxicity studies have been taken into account and the appropriate assessment factors have been used to define a PNEC value of 300 µg/l. Most of the available monitoring data apply to rivers and estuaries and were used to calculate PECs. The most recent data (1991-1995) support a typical PEC of 0.01 µg T112/l water and a worst case PEC of 5 µg T112/l water. The calculated PEC/PNEC ratios give a safety margin of 60 to 30,000 between the predicted no effect concentration and the exposure concentration. Additional evaluation of environmental fate and bioaccumulation characteristics showed that no concern is expected for food chain accumulation.     

Euro Chlor Risk Assessment for the Marine Environment Osparcom Region: North Sea - Chloroform

This risk assessment on chloroform was carried out specifically for the marine environment, according to the methodology laid down in the EU risk assessment Regulation (1488/94) and the Guidance Document of the EU New and Existing Substances Regulation (TGD, 1997). The study consists of the collection and evaluation of data on effects and environmental concentrations from analytical monitoring programs in large rivers and estuaries in the North Sea area. The risk is indicated by the ratio of the "predicted environmental concentrations" (PEC) and the "predicted no effect concentrations" (PNEC) for the marine aquatic environment. In total, 23 studies for fish, 17 studies for invertebrates and 10 studies for algae have been evaluated. Both acute and chronic toxicity studies have been taken into account and the appropriate assessment factors have been used to define a typical PNEC value of 72 µg/l. Due to limitations of the studies evaluated, a worst PNEC of 1 µg/l could also be used. Most of the available monitoring data apply to rivers and estuaries and were used to calculate PECs. The most recent data (1991-1995) support a typical PEC of 0.2 µg chloroform per litre of water and a worst case PEC of 5 to 11.5 µg chloroform per litre of water. The calculated PEC/PNEC ratios give a safety margin of 6 to 360 between the predicted no effect concentration and the exposure concentrations. A worst case ratio, however, points to a potential risk for sensitive species. Refinement of the assessment is necessary by looking for more data. Additional evaluation of environmental fate and bioaccumulation characteristics showed that no concern is expected for food chain accumulation.     

Euro Chlor Risk Assessment for the Marine Environment Osparcom Region: North Sea - Tetrachloroethylene

This risk assessment on tetrachloroethylene (PER) was carried out specifically for the marine environment, according to the methodology laid down in the EU risk assessment Regulation (1488/94) and the Guidance Document of the EU New and Existing Substances Regulation (TGD, 1997). The study consists of the collection and evaluation of data on effects and environmental concentrations from analytical monitoring programs in large rivers and estuaries in the North Sea area. The risk is indicated by the ratio of the "predicted environmental concentrations" (PEC) and the "predicted no effect concentrations" (PNEC) for the marine aquatic environment. In total, 18 studies for fish, 13 studies for invertebrates and 8 studies for algae have been evaluated. Both acute and chronic toxicity studies have been taken into account and the appropriate assessment factors have been used to define a PNEC value of 51 µg/l. Most of the available monitoring data apply to rivers and estuary waters and were used to calculate PECs. The most recent data (1991-1995) support a typical PEC of 0.2 µg PER/l water and a worst case PEC of 2.5 µg PER/l water. The calculated PEC/PNEC ratios give a safety margin of 20 to 250 between the predicted no effect concentration and the exposure concentration. Additional evaluation of environmental fate and bioaccumulation characteristics showed that no concern is expected for food chain accumulation.     

Euro Chlor Risk Assessment for the Marine Environment Osparcom Region: North Sea - Trichloroethylene

This risk assessment on trichloroethylene (TRI) was carried out specifically for the marine environment, according to the methodology laid down in the EU risk assessment Regulation (1488/94) and the Guidance Document of the EU New and Existing Substances Regulation (TGD, 1997). The study consists of the collection and evaluation of data on effects and environmental concentrations from analytical monitoring programs in large rivers and estuaries in the North Sea area. The risk is indicated by the ratio of the "predicted environmental concentrations" (PEC) and the "predicted no effect concentrations" (PNEC) for the marine aquatic environment. In total, 19 studies for fish, 30 studies for invertebrates and 14 studies for algae have been evaluated. Both acute and chronic toxicity studies have been taken into account and the appropriate assessment factors have been used to define a PNEC value of 150 µg/l. Most of the available monitoring data apply to rivers and estuaries and were used to calculate PECs. The most recent data (1991-1995) support a typical PEC of 0.1 µg TRI/l water and a worst case PEC of 3.5 µg TRI/l water. The calculated PEC/PNEC ratios give a safety margin of 40 to 1,500 between the predicted no effect concentration and the exposure concentration. Additional evaluation of environmental fate and bioaccumulation characteristics showed that no concern for food chain accumulation is expected.     

Euro Chlor Risk Assessment for the Marine Environment Osparcom Region: North Sea - 1,2-Dichloroethane

This risk assessment on 1,2-dichloroethane (EDC) was carried out specifically for the marine environment, according to the methodology laid down in the EU risk assessment Regulation (1488/94) and the Guidance Document of the EU New and Existing Substances Regulation (TGD, 1997). The study consists of the collection and evaluation of data on effects and environmental concentrations from analytical monitoring programs in large rivers and estuaries in the North Sea area. The risk is indicated by the ratio of the "predicted environmental concentrations" (PEC) and the "predicted no effect concentrations" (PNEC) for the marine aquatic environment. In total, 21 studies for fish, 17 studies for invertebrates and 7 studies for algae have been evaluated. Both acute and chronic toxicity studies have been taken into account and the appropriate assessment factors have been used to define a PNEC value of 1100 µg/l. Most of the available monitoring data apply to rivers and estuaries and were used to calculate PECs. The most recent data (1991-1995) support a typical PEC of 0.5 µg EDC/l and a worst case PEC of 6.4 µg EDC/l. The calculated PEC/PNEC ratios give a safety margin of 170 to 2200 between the predicted no effect concentration and the exposure concentration. Additional evaluation of environmental fate and bioaccumulation characteristics showed that no concern is expected for food chain accumulation.     

采用碘量法测定硫化物中值得注意的几个问题

针对碘量法测定水样中硫化物含量时硫离子具有较强的还原性，对测定结果影响较大的问题，提出了为减少测定误差采取的一些措施。     

散射光法测定水中浊度的研究

由国际通用的散射光测定浊度方法,结合国内常用的比浊法进行测定,解决了使用波长660nm吸收法测定的干扰影响,其监测结果同国内规定的标准方法测定结果一致。同时使用荧光光度计代替国内还没有大批生产的浊度散射光测定仪,仪器有多种可选择的分析条件,充分发挥仪器的性能。可适用于地面水和污染较严重水的测定要求。     

Turbidimetric determination of chloride in different types of water using a single sequential injection analysis system

A sequential injection analysis system for the turbidimetric determination of chloride in different types of water is proposed. The determination is based on the reaction of chloride with silver ions and the subsequent measurement of the turbidity caused by silver chloride precipitation. In this method, the use of toxic reagents, such as mercury thiocyanate, commonly employed in most spectrophotometric techniques for chloride determination, is avoided. The main feature of the developed system is the use of a single configuration to carry out the determination over a wide concentration range (2-400 mg L(-1)) by changing only the aspirated sample volume. This characteristic allows the determination of chloride in ground, surface and wastewaters using the same manifold. In addition, a considerable saving of precipitating reagent is achieved due to non-continuous consumption. The results obtained with the developed system were statistically indistinguishable from those of the potentiometric titration reference method. Relative standard deviations for ten consecutive injections were lower than 3.7%, with a sampling frequency of between 55 and 57 determinations per hour.     

New kinetic-spectrophotometric method for monitoring the concentration of iodine in river and city water samples

A new kinetic method has been developed for the determination of iodine in water samples. The method is based on the catalytic effect of I^? with the oxidation of Indigo Carmine (IC) by KBrO₃ in the sulfuric acid medium. The optimum conditions obtained are 0.16 M sulfuric acid, 1?×?10^?3 M of IC, 1?×?10^?2 M KBrO₃, reaction temperature of 35°C, and reaction time of 80 s at 612 nm. Under the optimized conditions, the method allowed the quantification of I^? in a range of 12–375 ng/mL with a detection limit of 0.46 ng/mL. The method was applied to the determination of iodine in river and city water samples with the satisfactorily results.