硒—硫氰酸钾—罗丹明B—明胶—OP体系分光光度法测定微量硒

硒的分光光度法一般采用硒试剂作显色剂，其灵敏度低，操作繁琐。硒－硫氰酸盐－丁基罗丹明Ｂ－吐温－２０体系分光光度法测定微量硒的灵敏度较高＾［１］，在该文的基础上，本人研究出硒－硫氰酸钾－罗丹明Ｂ－明胶－ＯＰ体系分光光度法，具有灵敏度高，稳定性好，操作简便等特点。研究结果表明：在明胶－乳化剂ＯＰ存在下，控制溶液ｐＨ３．８，用硫脲作还原剂，ＥＤＴＡ为掩蔽剂，硒与硫氰酸钾及罗丹明Ｂ生成三元配合物，配合比Ｓ     

Cu（Ⅱ）—茜素红S—甲基紫—聚乙烯醇体系光度测定痕量铜

提出了Ｃｕ（Ⅱ）－茜素红Ｓ－甲基紫－聚乙烯醇三元配合物体系光度法测定Ｃｕ（Ⅱ）的新方法，在聚乙烯醇存在的下，Ｃｕ（Ⅱ）－茜素红Ｓ－甲基紫形成稳定的有色配合物，通过测定该化合物的吸光度而测定Ｃｕ（Ⅱ）含量，测定了天然水样，试验表明，方法有较好的灵敏度和选择性，精密度可靠，适用于水样中痕量Ｃｕ（Ⅱ）的测定。     

光度法测定水中痕量铁——Fe（Ⅲ）—硫氰酸盐—罗丹明B—聚乙烯…

研究了Ｆｅ（Ⅲ）－硫氰酸盐－罗丹明Ｂ体系水相测定铁的方法。三元体系稳定性好，精密度高（含铁４μｇ铁样测定１０次，相对标准偏差为３．１％），灵敏度高。实测天然水中结果满意。     

用空气—乙炔火焰原子吸收法测定土壤中铝

ｌ引言空气－乙炔火焰原子吸收法测定铝时，共存离子的干扰十分严重，同时，铝在火焰中生成难熔性化合物，测定灵敏度极低，很难用空气－乙炔火焰测定。因此，土壤中铝的测定一直沿用化学分析法或Ｎ２Ｏ－Ｃ２Ｈ２火焰原子吸收法。我们根据Ｎ２Ｏ－Ｃ２Ｈ２火焰法测定铝时，火焰中产生的氰化物具有很强的还原性，能提高铝的测定灵敏度，据此推断将含氮有机化合物喷入空气－乙炔火焰中也可能产生氰基，从而提高铝的测定灵敏度。本文采用常用的空气－乙炔火焰原子吸收法测定铝，研究了添加水溶性有机化合物四甲基氯化铵（ＴＭＡＣ）时的基体改…     

水杨醛—5—溴—水杨酰腙的合成及其与钪荧光反应的研究

腙类试剂荧光法测定A13＋[1]、Ga3＋[2]、Mn2＋[3]已显示出灵敏度高及选择性好等优点，但尚未见水杨醛一5一澳一水杨酸踪（简称SABSH）荧光法测定无机离子的报道．本文合成了SAB－SH，测定了试剂酸离解常数，研究了试剂与抗荧光反应的最佳条件，建立的分析方法相对标准偏差为0．95％，检测下限为0．15ng／mL，考察了40种共存离子的干扰情况．结果表明，在选择性较好的条件下，该法同用各种综试剂荧光法测定其它无机金属离子比较具有灵敏度高的优越性［’－’j，将其用于经预分离的土壤地质样中痕量锐的测定，结果满意．1实验部分1．l…     

7—碘—8—羟基喹啉—5—磺酸—溴化十六烷基三甲铵荧光光度法测定痕量镥

本文研究了镥－Ｆｅｒｒｏｎ－表面活性剂三元荧光体系的荧光特性，各种表面活性剂中以溴化十六烷基三甲铵的增敏效果最佳，与相应的二元体系相比较，灵敏度提高近１０倍。镥的测定下限可达８．８ｎｇ／ｍｌ。本法与Ｐ５０７萃取色谱分离法相结合可用于天然混合稀土氧化物中痕量镥的测定，结果较满意。     

锆—7—（1—苯偶氮）—8—羟基喹啉—5—磺酸—Triton X—100荧光熄灭法测定锆

基于在pH＝4．5～5.5、TritonX－100存在下、锆同7－（1-苯偶氮）－8-羟基喹啉-5-磺酸形成组成比为1：3的黄色络合物使荧光熄灭，建立了荧光熄灭测定锆的新方法。该方法的线性范围为0～28μgZrO2／L，检测限为0．5μg／L，体系稳定，灵敏度高，用于α-βAl2O3及瓷釉中锆的测定，结果满意。     

钴—5,10,20—四（3—甲氧基—4—羟基苯基）卟啉修饰玻碳电极的L—抗坏血…

将水合５，１０，１５，２０－四－（３－甲氧基－４－羟基苯基）钴卟啉修饰在玻碳电极表面，制成ＣｏＴＭＨＰＰ修饰电极，电极稳定性好且灵敏度高，对抗坏血酸有良好的电催化氧化作用，测定线性响应范围为１．０×１０＾－５－１．０×１０＾－２ｍｏｌ／Ｌ，响应时间小于１２ｓ。本研究了电极的性质和应用，并用于药物中抗坏血酸的测定，其测定结果与碘量法一致。     

流动注射—氢化物—石墨炉原子吸收光谱法应用研究

本文采用自制的氢化物－石墨炉自动进样器及流动注射仪，直接测定了一些环境试样中的痕量锗，并研究了测定条件，该方法灵敏度高，线性范围宽，操作简单，速度快，耗样量少。特征质量：５．７ｐｇ／０．００４４Ａ；检出限：１．３ｐｇ，测定速度：３０个样／ｈ；回收率：９９．５％－１０４％。     

非离子型微乳液对Pb（Ⅱ）—2—（5—溴—吡啶偶氮）—5—二乙氨基酚显色反应的增敏

以含水量90％的O／W乳化剂OP／正丁醇／正庚烷／水非离子型微乳液为介质，以5-Br-PADAP为显色剂，进行了Pb(Ⅱ)的吸光光度测定。其最大吸收波长λmax为540nm，表观摩尔吸光系数达1．07×105，与相应的胶束体系比较，测定灵敏度提高了近1倍，Pb(Ⅱ)在0～15μg／25ml范围内符合比耳定律。用于废水中微量铅的测定，结果满意。     

Determination of iodine in diverse botanical and dietary matrices by pre-irradiation combustion followed by neutron activation analysis

Summary The method chosen for determination of iodine in this investigation is an extension of an existing analytical technique to food samples which was developed for environmental samples. The method is based on pre-irradiation combustion of the sample to liberate iodine, trapping the iodine on charcoal, and quantitating the element by neutron activation analysis (NAA). Existing botanical and dietary reference materials were used to check the validity of the method. Several mixed diet samples with high fat content from the U.S. Total Diet Study and composites of cereals with both low and high iodine content were analyzed. This method of pre-irradiation combustion followed by NAA has been shown to be a viable technique for the determination of iodine in dietary samples. However, with a detection limit of about 50 ng of iodine, large amounts of sample (>1 g) are typically required for each determination.     

Determination of iodine in common salt by an automatic reaction-rate method

An automatic reaction-rate method is described for the ultramicro determination of iodine in common salt. The method utilizes the acceleration of the reaction between ceric sulfate and arsenious acid by iodine. The time required for the reaction to consume a fixed amount of ceric ions is measured automatically and related directly to the iodine concentration. Measurements btained in salt samples containing 3 to 7500 μg of iodine per 100g were precise to within 2% or 0.3 μg of iodine, whichever is larger. Measurement times varied from a few sec to about 2min.     

Iodine in mineral waters: A comparison of results from two analytical techniques

A comparative study of the determination of iodine in mineral waters is presented. Iodine was first determined by a standard titrimetric method and the results obtained were compared with those obtained by the faster and more sensitive radiochemical neutron activation method. For a series of waters, the results obtained by the two techniques were in fair agreement for the higher concentration levels of iodine, but for very low iodine levels the titrimetric method was insufficiently sensitive. The RNAA procedure was checked by standard addition experiments, and shown to be also valid when iodine was present as iodate.The paper was presented in part at the ISM XI, Wiesbaden, August 1989     

一种新的FIA导数光谱技术测定食盐中碘含量

提出一种新的流动注射导数光谱检测技术,即双光束同时扫描法。将自行研制的流动池比色装置分别安置在双光束检测器中样品光束和参比光束的光路中,实现同时扫描,获得响应曲线为一阶导数光谱。对该方法的原理和实验技术进行了讨论,基于碘酸根与碘化钾生成碘,并与淀粉生成蓝色络合物(λmax=574 nm)原理,确定了最佳实验条件,建立了一种导数光谱法测定加碘食盐中的碘含量。该法分析速度为130次/h,方法灵敏度比普通FIA法提高了1.8倍,测定结果的相对标准偏差为0.97%(n=9),方法可直接用于实际样品中碘含量的检测。     

Chemical template directed iodine patterns on the octadecyltrichlorosilane surface

A carboxylic-terminated nanometer-scale chemical pattern on an octadecyltrichlorosilane (OTS) surface can guide the deposition and crystallization of iodine, forming an iodine pattern on the chemical pattern. The iodine in the pattern is gel-like when fabricated by the solution-deposit method. In contrast, a dendritic, snowflake-shaped polycrystalline iodine sheet is formed by the vapor-phase condensation method. The data demonstrate that iodine is a good tracing and visualizing agent for studying liquid behavior at the nano scale. The topography of the iodine stain reveals that the "coffee ring" effect can be suppressed by reducing the pattern size and increasing the evaporation rate. The chemical template-bound iodine pattern has an unusually low vapor pressure and it can withstand prolonged baking at elevated temperature, which differs significantly from bulk iodine crystals.     

Colorimetric determination of inorganic iodine in fortified culinary products

The presented colorimetric procedure only requires simple laboratory equipment and is suitable as a routine procedure for checking concentrations of iodine in fortified culinary products. The Moxon and Dixon colorimetric procedure for iodine determination has been optimised for the determination of iodide and iodate in fortified culinary products, always containing high salt levels. The high sensitivity of the method permits a high dilution of the product solutions, thus reducing interferences from the inherent colour of the products. The calibration is linear in the range from 0 to 12 microg L(-1) of iodine with R2 > 0.99. A series of commercial culinary products were used to validate the method. Recoveries of iodine, added as iodide and/or iodate, were generally in the range 100+/-10%. High concentrations of chloride are essential to obtain a complete recovery of iodate. Limit of quantification was estimated to be 2 mg kg(-1) of product, based on 2-3 g of product. Concentrations of iodine determined with this method were similar to those obtained by an ICP-MS procedure.     

Determination of iodine in seafood by inductively coupled plasma/mass spectrometry.

A method was developed for determination of total iodine content in different standard reference materials (SRMs) and seafood products by inductively coupled plasma/mass spectrometry (ICP/MS). If iodine is present as iodide and nitric acid is used in the wet digestion system, the observed signal is not stable when iodine is measured by ICP/MS at m/z 127. To stabilize the iodine signal, 3% ammonia solution (1 + 1, v/v) was added to the digest. The limit of quantitation of the method, defined as 6 times the standard deviation in the blank solution (n = 20) was estimated to be 15 mg/kg (using 0.2 g dry mass and a dilution factor of 50). The precision, expressed as repeatability of the iodine concentration, varied between 3.2 and 12% in SRMs, with concentrations of 4.70-0.17 mg/kg dry matter. The described method was compared with a method using tetramethylammonium hydroxide extraction. Both methods showed good precision and trueness by analyses of SRMs. The 2 methods were used to determine iodine in seafood from the Barents Sea, the Norwegian Sea, and the North Sea. The results showed great variation between different fish species as well as between individuals within a species. The lowest values of iodine were recorded in muscle of ling (Molva molva) with a mean of 0.07 mg/kg fresh weight and a variation between 0.03 and 0.11 mg/kg fresh weight. The highest values were found in cod (Gadus morhua) from the Barents Sea, with a mean of 2.5 mg/kg and a variation between 0.7 and 12.7 mg/kg fresh weight.     

An improved method for the flow-injection determination of iodine using the luminol chemiluminescence reaction in a reversed micellar medium of cetyltrimethylammonium chloride in 1-hexanol-cyclohexane.

To eliminate the use of chlorinated hydrocarbons, we have improved the method for the flow-injection (FI) determination of iodine based on the chemiluminescence reaction of iodine with luminol in a chloroform-free reversed micellar medium of the surfactant cetyltrimethylammonium chloride (CTAC) using a mixture of 1-hexanol-cyclohexane as a bulk solvent. The FI procedure used simply involves the mixing of an iodine solution in cyclohexane with the chemiluminescent reagent solution of luminol in the reversed micellar medium of CTAC in 0.38 M 1-hexanol in cyclohexane/water (buffered with sodium carbonate). The optimum conditions for the iodine determination were evaluated and a detection limit (DL) of 0.05 ng cm(-3) iodine was achieved. The calibration graph obtained was linear with a dynamic range from the DL to 10 ng cm(-3) iodine. The relative standard deviations (n=5) observed at all concentrations within the linear range were less than 2.5%. The improved FI method is rapid and equally sensitive like the original one and was found to be suitable for the determination of trace iodine.     

Head-space flow injection for the on-line determination of iodide in urine samples with chemiluminescence detection

A simple head-space (HS) flow injection (FI) system with chemiluminescence (CL) detection for the determination of iodide as iodine in urine is presented. The iodide is converted to iodine by potassium dichromate under stirring in the closed HS vial, and the iodine is released from urine by thermostatting and is carried in a nitrogen flow through an iodide trapping solution. The concomitant introduction of aliquots of iodine, luminol and cobalt(II) solutions by means of a time-based injector into an FI system allowed its mixing in a flow-through cell in front of the detector. The emission intensity at 425 nm was recorded as a function of time. The salting-out of the standard solutions affected the gas-liquid distribution coefficient of iodine in the HS vial. The typical analytical working graphs obtained under the optimized experimental conditions were rectilinear from 0 to 5 mg l(-1) iodine, achieving a precision of 2.3 and a relative standard deviation of 1.8 for ten replicate analyses of 50 and 200 microg l(-1) iodine. However, a second-order process becomes significant at higher iodine concentrations (from 10 to 40 mg l(-1)). The detection limit of the method is 10 microg l(-1) (80 ng) iodine when 8 ml samples are taken. Data for the iodide content of 10 urine samples were in good agreement with those obtained by a conventional catalytic method, and recoveries varied between 101 and 103% for urine samples spiked with different amounts of iodide. The analysis of one sample takes less than 20 min. In the present study the iodide levels found for 100 subjects were 86.8 +/- 19.0 (61-125) microg l(-1), which is lower than the WHO's optimal level (150-300 microg per day).