TPPS4导数光度法同时测定茶叶中铜和锌

用pH 7.6的Na2B4O7-HCl缓冲溶液控制溶液的酸度,在OP存在下,meso-四(4-磺基苯基)卟啉与Cu2+和Zn2+在沸水浴中同时起显色反应.用Mn2+减少试剂峰对Zn2+测定的影响,其四阶导数光谱能同时测定铜和锌.Cu2+在0～0.072mg@L-1、Zn2+在0～0.096mg@L-1时遵守比耳定律,用于茶叶中铜和锌的测定,结果满意.     

溴酚红-过氧化氢催化光度法测定痕量锌

在稀氢氧化钠介质中,Zn2+催化过氧化氢氧化溴酚红的褪色反应,通过试验确定了测定条件,建立了一个催化动力学光度法测定痕量锌的方法。Zn2+的检出限为1.5×10-7g.L-1,线性范围为0~4.8×10-2mg.L-1,方法用于测定头发中痕量锌。     

正丙醇-氯化钠-4-(2-吡啶偶氮)-间苯二酚双水相萃取光度法测定工业废水中的Zn~(2+)

研究了在简单的丙醇-氯化钠双水相体系中4-(2-吡啶偶氮)-间苯二酚(PAR)与Zn2+形成的配合物的分配行为,建立了分离和测定工业废水中Zn2+的双水相萃取光度分析方法。结果表明,在pH=8.0的Na2B4O7-HCl缓冲溶液中,PAR与Zn2+形成的配合物被萃取到丙醇中,其最大吸收波长为493nm,与PAR和丙醇水溶液的混合液相比,发生了88nm的红移。在该条件下,Zn2+在0.05~0.25μg·mL-1范围内符合比尔定律,其相关系数为0.9989,表观摩尔吸光系数ε为2.26×104 L·mol-1·cm-1。该方法测定工业废水中的Zn2+与原子吸收法结果一致。     

催化过氧化氢氧化杨梅红色素褪色光度法测定痕量锌

报道了杨梅红色素的提取与性质。基于加热条件下 ,Zn2 + 催化过氧化氢氧化杨梅红色素灵敏的褪色反应 ,提出了测定痕量锌的新方法。所建立的方法对Zn2 + 的线性范围为 0 .2～ 1 .0 μg L,并成功地用于发样和奶粉中锌的测定     

新型主体试剂交联聚合β-环糊精-邻香草醛苯甲酰腙的合成及荧光法识别锌

合成了新型主体试剂交联聚合 β 环糊精 邻香草醛苯甲酰腙 (β CDP OVBH) ,探讨了与Zn2 + 的荧光识别反应。在pH =8.30的NH3·H2 O NH4 Ac ,5 .0 0mLDMF中 ,β CDP OVBH与Zn2 + 络合生成 1∶1的包合物 ;线性范围 2 .5 0～ 5 0 0 μg L ;检测限 0 .6 0 8μg L ;2 8种常见离子干扰实验的研究 ,显示出该主体试剂对客体Zn2 + 有较高的选择识别效果。方法简便、快速地用于茶叶、人发中痕量锌的测定 ,结果满意。     

络合吸附溶出伏安法测定茶叶中的痕量锌

通过实验优化支持电解质、pH值、络合剂浓度等实验参数。在溶液中直接以SCN-作配位剂 ,采用玻碳电极同位镀汞的吸附伏安法测定锌。在该体系中 ,Zn2 + 和SCN-配合物可产生灵敏吸附波 ,峰电位为 - 1.372V ,线性范围为 1.96 2～ 130 .8μg/L ,搅拌富集 5min ,检出限可达 8× 10 -10 mol/L。该法用于测定茶叶中的锌 ,平均回收率为 95 .0 %～ 10 2 .5 %。     

溴代苯基荧光酮分光光度法同时测定人体血浆中的痕量锗和锌

研究了在溴化十六烷基三甲基铵(CTMAB)的存在下, 溴代苯基荧光酮(BPF)与锗和锌反应分别形成稳定的络合物, 可用来同时测定Ge4 和Zn2 . 锗和锌络合物的最大吸收波长分别在540和565 nm处, 摩尔吸光系数分别为1.66×105和 4.35×104 L·mol-1·cm-1. 并利用k系数法进行校正避免Ge4 和Zn2 之间的干扰, 用于人体血浆中锗、锌的测定.     

1-(2,6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯光度法测定葡萄糖酸锌中的锌

目前用光度法测定锌的有机试剂主要有双硫腙和偶氮类试剂。三氮烯试剂是一类测定 Cd2 +、Hg2 +等金属离子的灵敏试剂 ,但用于样品中的 Zn2 +的测定报道较少。笔者用新合成的显色剂 1 - ( 2 ,6-二氯 - 4-硝基苯 ) - 3- ( 4 -硝基苯 ) -三氮烯直接光度法测定葡萄糖酸锌口服液中的锌 ,样品不需前处理 ,操作简便 ,具有较高的灵敏度和较好的重现性     

微分电位溶出法连续测定饮料中的铜铅镉锌

建立了微分电位溶出法连续测定饮料中痕量铜、铅、镉、锌的新方法。在HAc- Na Ac( p H4 .5)～ 3.5× 1 0 -2 mol·L-1KCl～ 2 .6× 1 0 -5 mol· L-1Hg2 +介质中测定锌 ,然后调节底液为 0 .0 1 mol·L-1HCl,连续测定铜、铅、镉。铜、铅、镉、锌 ,检出限分别为 4 ,0 .1 ,2 ,4 μg· L-1,线性测定范围 Zn2 +:0～ 30 0 μg·L-1,Cu2 +、Pb2 +、Cd2 +:0～ 2 2 0μg· L-1,回收率为 83.4 %～ 1 0 3.3% ,RSD<3.4 % ( n=7)。该法较好解决了金属互化物的影响 ,样品不需消化便可直接测定。     

催化极谱法测定锌电解液中微量钴

在湿法炼锌厂 ,锌电解液中杂质钴对析出锌的质量和锌电解的电流效率影响较大。传统工艺用黄药净化除钴 ,对钴的测定要求是 1μg· ml-1,通常采用亚硝基 - R盐比色法测定。自采用锑盐深度净化工艺后 ,对钴的测定要求为 0 .1 μg· ml-1,亚硝基 - R盐比色法的灵敏度达不到这个要求。本文在文献 [1 ,2 ]基础上采用催化极谱法测定钴 ,在柠檬酸铵 -盐酸羟胺底液中 ,Co( )与丁二酮肟形成的络合物在示波极谱仪上产生波形良好的催化极谱波 ,波峰电位为 - 1 .1 V(vs.SCE)。Zn2 +在此底液中的还原极谱波的波峰电位为 - 1 .3V,严重影响 Co2 +的催化…     

The determination of traces of arsenic in water by arsine generation and radiometric analysis

A tracer method based on the concentration-dependent distribution principle has been developed for trace arsenic determination. Standard and sample arsenic solutions labelled with a fixed amount of radioactive arsenic-74 are isolated by arsine generation with sodium borohydride followed by absorption in potassium iodide—iodine solution. The separated arsenic(III) is then extracted with equal but limited amounts of zinc diethyldithiocarbamate in chloroform and determined radiometrically by the concentration-dependent distribution principle. The method is practically free from interferences, and arsenic in aqueous solution as low as 0.5 ng ml^-1 can be determined. Results for natural and environmental water samples are compared with results obtained by the arsine generation-atomic absorption technique.     

Atomic absorption spectrometric determination of copper,zinc, and lead in geological materials

An atomic absorption spectrometric method is described for the determination of copper, zinc, and lead in geological materials. The sample is digested with HF—HCl—H₂O₂; the final solution for analysis is in 10 % (v/v) HCl. Copper and zinc are determined directly by aspirating the solution into an air—acetylene flame. A separate aliquot of the solution is used for determination of lead; lead is extracted into TOPO-MIBK from the acidic solution in the presence of iodide and ascorbic acid. For a 0.50-g sample, the limits of determination are 10–2000 p.p.m. for Cu and Zn, and 5–5000 p.p.m. for Pb. As much as 40 % Fe or Ca. and 10 % Al, Mg, or Mn in the sample do not interfere. The proposed method can be applied to the determination of copper, zinc, and lead in a wide range of geological materials including iron- and manganese-rich, calcareous and carbonate samples.     

完全脱乙酰化壳聚糖与Zn(Ⅱ)的配位作用

在均相反应条件下 ,完全脱乙酰化的壳聚糖与ZnSO4 进行配位反应 .用元素分析、IR、固体13 C NMR、UV vis、TGA和X 衍射等表征方法研究了Zn(Ⅱ )与壳聚糖所形成配位聚合物的组成和结构 .在pH =7时 ,一个Zn(Ⅱ )与二个壳聚糖重复单元中的氨基和仲羟基进行了配位     

An improved iodometric method for the successive determination of copper and zinc

The method described by haider and khundkar for the succesive iodometric dctcrmination of copper and zinc gives results that arc too low both for copper and for zinc. The errors may amount to —20% for copper and to —5% for zinc. The causes of these errors arc traced and eliminated and an improved method for the succesive iodometric determination of copper and zinc is described.     

The determination of arsenic in rocks,sediments and minerals by arsine generation and atomic absorption spectrometry

An arsine generation-atomic absorption method for the rapid and precise determination of 0.04–4000 p.p.m. arsenic in geological materials is described. The siliceous sample is decomposed with perchloric, nitric and hydrofluoric acids and potassium permanganate solution, and the residue is dissolved in dilute hydrochloric acid. Arsine is generated with potassium iodide, tin(II) chloride and zinc powder, and introduced to an argon—hydrogen flame. The method is applied to various standard rocks, NBS mineral standards, and geochemical exploration samples. The relative standard deviation is 4–14 %.     

Flame atomic absorption spectrometric determination of zinc after colloid precipitate flotation with hydrated iron(III) oxide and iron(III) tetramethylenedithiocarbamate as collectors

Colloid flotation of zinc from fresh water with a combination of two collectors, hydrated iron(III) oxide (Fe(2)O(3).xH(2)O) and iron(III) tetramethylenedithiocarbamate (Fe(TMDTC)(3)), permits rapid separation of the precipitate before its atomic absorption spectrometric (AAS) analysis. All important parameters necessary for the successful flotation like optimal mass of collectors, pH of the medium, electrokinetic potential of the collector particle surfaces, type of tenside, induction time etc., were checked. At the optimal pH value of medium (5.5) establishing by recommended procedure, zinc was separated quantitatively (97.4-98.8%) with 5 mg Fe(III) as constitutive element of the two collectors used. The content of zinc was determined by flame atomic absorption spectrometry (FAAS). These results were compared with the results obtained by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The FAAS detection limit for zinc is 9.4 mug 1(-1). The proposed method is simple, rapid and applicable to the zinc separation at mug 1(-1) levels from a large volume of water.     

Determination of copper and zinc in serum by derivative atomic absorption spectrometry using the microsampling technique

A method has been developed for the determination of copper and zinc in the serum of rats by derivative microsampling flame atomic absorption spectrometry (D-MFAAS). The microsampling volume, solution uptake rate and other figures of merit of the proposed methodology were studied. For a 100 microl volume, the characteristic concentrations and detection limits (3s) of D-MFAAS were 0.023 and 0.013 microg ml(-1) for copper and 0.0066 and 0.0080 microg ml(-1) for zinc, which were 4.5-6.5-fold better than those of microsampling flame atomic absorption spectrometry (MFAAS). The detection limits and sensitivities of D-MFAAS were 6.4- and 16-fold for 300 microl volume for copper, 14- and 13-fold for 250 microl volume for zinc, better than those of MFAAS. The method demonstrates high tolerance to interferences, and the analytical results obtained for a certified reference material, GBW 08551 Pork Liver, were in good agreement with the certified values. The recovery with the standard additions method was good, in the range 97.6-101.5%, and precisions (relative standard deviations) obtained for a diluent sample containing 0.5 microg ml(-1) copper and 0.7 microg ml(-1) zinc were 4.0% and 3.5% (n = 15) for copper and zinc, respectively.     

Complexometric titration of Aluminium

A procedure is given for the complexometric titration of aluminium. A known volume of a standard solution of EDTA is added to the sample solution, and the excess is back-titrated with a zinc sulphate solution, dithizone being used as indicator. The titration is performed at pH = 4.0 — 4.5 and 40 — 50% alcohol is added as solvent for the indicator.The theoretical basis of the method is developed, and the theoretical titration error with various amounts of aluminium and zinc is calculated.The results of some titrations are given.     

Spectrophotometric determinationof zinc in cooking salts,tap and mineral waters with phenylglyoxal mono(2-pyridyl)hydrazone

The behaviour of phynylglyoxal mono(2-pyridyl)hydrazone (PGMPH) with various metal ions was studied by spectrophotometry. The reaction of zinc with PGMPH provides a sensitive and precise method for the determination of zinc in tap and mineral waters and in cooking salts. Zinc ion reacts with PGMPH at pH 7.2—8.5 in solutions containing 40% (v/v) ethanol to form a yellow-orange complex with maximum absorbance at 464—470 nm. The molar absorptivity of the 1:2 ZnPGMPH complex is 71 300 1 mol^?1 cm^?1. Interferences are considered in detail.     

对氯苯基荧光酮与锌显色反应的研究及应用

在阳离子表面活性剂溴化十六烷基三甲胺（CTMAB）存在下,研究了对氯苯基荧光酮（P—CPF）与锌的显色反应条件和光度性质。在pH=8．4的Na2HPO4-KH2PO4缓冲溶液中,锌与P—CPF形成1：1的红色络合物,所形成的络合物的最大吸收波长位于568nm处,表观摩尔吸光系数为7．20&#215;10^4L&#183;mol^-1&#183;cm^-1;红色络合物至少稳定10h以上,锌含量在0～2．40μg／5mL范围内符合比耳定律。拟定方法用于药物中微量锌的测定,结果满意。