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1.
催化动力学光度法测定痕量硫离子   总被引:2,自引:0,他引:2  
基于氢氧化钠溶液中,S~(2-)对H_2O_2氧化I-的反应有催化作用,固定反应时间,将此催化体系与二苯胺碘酸钠氧化显色反应相偶合,建立了催化动力学光度法测定痕量硫离子的新方法,并讨论了其动力学条件。方法灵敏度1.4×10~(-11)g/mL,测定范围1.0~12.0ng/mL。操作简便快速,用于测定天然水及含硫工业废水中的痕量硫离子,结果满意。  相似文献   

2.
铬蓝黑B指示催化动力学测定痕量钒的研究   总被引:9,自引:2,他引:7  
本基于在酸性条件下,钒对溴酸钾氧化铬蓝黑B反应的催化作用,建立了测定痕量钒的催化动力学新体系。以极谱法测定的线性范围为0~10ng/10mL, 检测下限为1.4×10^-12g/mL;以光度法测定的线性范围为0~10ng/6mL<检测下限为1.11×10^-11g/mL。应用于饮用水及人发中痕量钒的测定,结果满意。  相似文献   

3.
本文提出一种测定痕量钼的微分吸附计时电位法,利用悬汞电极作为工作电极,在0.12mol/LHAc-0.01mol/L,NaAc-3.2×10^-6mol/L茜素红的最佳底液中,测定钼的线性范围为0.4ng/mL~70ng/mL,吸附富集3min检测下限可达0.1ng/mL。探讨了影响方法灵敏度的主要因素,初步研究了电极过程,利用该方法直接测定了粮食样品中钼的含量。  相似文献   

4.
超痕量铱的催化荧光分析新方法研究   总被引:2,自引:0,他引:2  
在0.1mol/L H2SO4介质及加热条件下,超痕量Ir强烈催化KIO4氧化罗丹明B生成一种绿色荧光产物,藉自来水冷却中止反应,研究了催化荧光法测定超痕量铱的影响因素,建立了一个检出限和测定范围分别为0.005ng/mL和0.01-2ng/mL铱的催化荧光分析新方法,并探讨了催化反应的机理。  相似文献   

5.
离子对高效液相色谱—TPPS4光度法测定痕量锌和铜   总被引:2,自引:1,他引:1  
雷呈宏  汤福隆 《分析试验室》1995,14(2):15-17,21
本文用TPPS4作柱前衍生试剂,研究了试剂与锌和铜的配位反应,在ODS柱上,用乙腈/水体系作流动相,苄基三乙基氯化铵作离子对试剂,在415nm处检测,提出了离子对高效液相色谱-光度法快速分离测定痕量锌铜的新方法,检测限:Zn和Cu分别为0.15和0.10ng/mL,本法用于花生样品中痕量Zn,Cu的测定。结果与AAS一致。  相似文献   

6.
溶剂浮选光度法测定痕量铜   总被引:21,自引:3,他引:18  
提出了利用溶剂浮选富集DDTC-Cu(Ⅱ)体系测定水样中痕量铜的方法(DDTC为二乙胺二硫代甲酸钠)。质量浓度的检出限为0.05ng·mL^-1,线性范围为0.0 ̄6.0ng·mL^-1,测定含Cu(Ⅱ)4.0ng·mL^-1的样品,相对标准偏差为0.85%,已用于天然水中Cu(Ⅱ)的测定。  相似文献   

7.
本文用TPPS_4作柱前衍生试剂,研究了试剂与锌(Ⅱ)和铜(Ⅱ)的配位反应,在ODS柱上,用乙腈/水体系(28%,V/V)作流动相,苄基三乙基氯化铵作离子对试剂.在415nm处检测,提出了离子对高效液相色谱。光度法快速分离测定痕量锌铜的新方法,检测限:Zn和Cu分别为0.15和0.10ng/mL,本法用于花生样品中痕量Zn、Cu的测定,结果与AAS一致。  相似文献   

8.
慕卫 《分析化学》1998,26(5):571-573
提出了用高效液相色谱法同时测定土壤中莠去津、氰草津残留量的方法。用甲醇/乙腈提取,石油醚脱脂,中性氧化铝小柱净化,最后用Nova-PakC16柱进行HPLC分析,流动相:甲醇-水(55+45),吸收波长 228 nm,流速0. 7 mL/min.莠去津最低检出限为 0.3 ng,氰草津为0.2 ng。回收率分别为莠去津83.4%~102.3%,氰草津 82.4%~93.5%.  相似文献   

9.
催化动力学光度法测定痕量铁的研究   总被引:9,自引:0,他引:9  
本文研究了在稀硫酸介质中铁催化过氧化氢氧化胭脂红的褪色反应及其动力学条件,测定了反应级数和表现活化能,建立了测定痕量铁的新方法。该方法的检出限为0.25ng/mLFe,线性范围为0~0.4μg/25mLFe,方法简便、快速、灵敏度高。应用于水及食品中痕量铁的测定,结果满意。  相似文献   

10.
王军锋  章竹君 《分析化学》1995,23(3):299-301
本文提出用硫胺素-高磺酸钠作为指示反应,流动注射光导纤维动力学荧光法测定痕量锰,检测限达0.4ng/mL;相对标准偏差小于1%;采样频率为45样次/h。用于直接测定纯铝及铝合金的痕量锰,结果满意。  相似文献   

11.
Zhang G  Li B  Fan J  Feng S 《Talanta》1997,44(7):1141-1147
A simple and very sensitive kinetic fluorimetric method is reported for the determination of trace amount of thiocyanate. The proposed method is based on the inhibition effect of thiocyanate on oxidation of rhodamine 6G by potassium bromate in sulfuric acid solution. The detection limit for thiocyanate is 1.63 x 10(-6) mmol/l. The linear range of the determination is 4.82 x 10(-6)-4.13 x 10(-5) mmol/l. This method has been used to determine trace thiocyanate in urine and saliva of smokers and non-smokers. The results obtained are satisfactory.  相似文献   

12.
A new method for the separation of trace amounts of palladium from hydrochloric acid and potassium thiocyanate media has been established based on the formation of an ion-pair complex of palladium thiocyanate anion Pd(SCN)4(2-) and the cationic potassium complex of dicyclohexyl- 18-crown-6 (DC18C6) in chloroform. The effect of various factors (solvent, crown ether, potassium thiocyanate, hydrochloric acid, reagent concentration, shaking time, phase volume ratio, composition of the extracted species, foreign ions, etc.) on the extraction and back-extraction of palladium has been investigated. The method can be combined with subsequent FAAS determination of palladium. The procedure was applied to determine palladium traces in chloroplatinic acid and rhodium chloride.  相似文献   

13.
A sensitive spectrophotometric method for the determination of trace amounts of cobalt based on the complex formation with nitrosochromotropic acid in ammoniacal medium is described. After its extraction as thiocyanate complex into isobutylmethyl ketone, cobalt is stripped into nitrosochromotropic acid in ammonia buffer. The method has been applied to the determination of cobalt in mild steel, ferrous alloys and multivitamin preparations.  相似文献   

14.
A new method for the separation of trace amounts of palladium from hydrochloric acid and potassium thiocyanate media has been established based on the formation of an ion-pair complex of palladium thiocyanate anion Pd(SCN)4 2– and the cationic potassium complex of dicyclohexyl-18-crown-6 (DC18C6) in chloroform. The effect of various factors (solvent, crown ether, potassium thiocyanate, hydrochloric acid, reagent concentration, shaking time, phase volume ratio, composition of the extracted species, foreign ions, etc.) on the extraction and back-extraction of palladium has been investigated. The method can be combined with subsequent FAAS determination of palladium. The procedure was applied to determine palladium traces in chloroplatinic acid and rhodium chloride.  相似文献   

15.
在pH 11.4的NH3-NH4Cl缓冲溶液中,阳离子表面活性剂溴代十四烷基吡啶(TPB)对硫氰酸根阻抑高碘酸钾氧化间甲酚紫的褪色反应具有明显的增敏作用,据此建立了动力学光度法测定微量SCN-的新方法,该方法的线性范围为0.04~0.72 μg/mL,检出限6.74×10-3 μg/mL.可用于测定吸烟和非吸烟者的尿液中的微量SCN-.  相似文献   

16.
A selective and sensitive method is described for the determination of trace amounts of molybdenum, based on its reaction with thiocyanate and its extraction (into toluene) as an ion-association complex formed with adogen (methyltrioctylammonium chloride). The molar absorptivity is 2.13 x 10(4) l.mole(-1).cm(-1) at lambda(max) 467 nm. The method has been applied to molybdenum determination in steels.  相似文献   

17.
This study reports a sensitive kinetic spectrophotometric method for the determination of trace amounts of thiocyanate. In acidic solution, Methylene Blue (MB) is oxidized by bromate to form a colorless compound. The reaction is accelerated by trace amounts of thiocyanate and can be followed by measuring the absorbance at 664 nm. The absorbance of the reaction decreased with an increase in the reaction time. Under the optimum experimental conditions (0.56 M of sulfuric acid, 3.9 x 10(-5) M of MB, 3.0 x 10(-3) M of bromate, 180 s, 25 degrees C), thiocyanate can be determined in the range 5.0 - 180 ng/ml. The relative standard deviations (n = 8) are 2.81 and 1.43% for 10.0 and 150 ng/ml thiocyanate, respectively. The detection limit of this method is (3sigma) 3.8 ng/ml. This method was successfully applied to the determination of thiocyanate in real samples.  相似文献   

18.
A simple, selective and rapid method for solid phase extraction and spectrophotometric determination of thiocyanate using a manganese (III) tetrakis (p-sulfonatophenyl) porphyrin, [Mn (TPPS) OAC] bound to Amberlite IR-400 has been developed. The influence of pH, amount of solid phase, sample matrix, type and amount of eluting agent and flow rates i.e. variables affecting the efficiency of the extraction system were evaluated and conditions of the sample, eluting solution and active phase were optimized. The maximal capacity was found to be as 1.16 microg mL(-1) for 1200 mL. Thiocyanate ions can be eluted quantitatively with 8 mL 0.3 M ferric chloride. The enrichment factor was 150. The linear range of the determination is between 0.4-2.0 microg mL(-1) for preconcentration method with a limit of detection of 2.8 ng mL(-1). The method has been successfully applied for determination of trace amounts of thiocyanate in tap water, saliva sample and a synthetic mixture.  相似文献   

19.
浊点萃取-分光光度法测定自来水及酒类样品中的痕量铁   总被引:2,自引:0,他引:2  
昌征  阎宏涛  黄家剑 《化学学报》2010,68(7):717-721
利用非离子表面活性剂TritonX-100在温度高于其浊点时形成相分离行为,建立了浊点萃取-分光光度法测定痕量铁的新方法,探讨优化了以KSCN为显色剂,TritonX-100浊点萃取富集痕量铁的实验条件.研究发现:加入正辛醇可使TritonX-100的浊点降低约30℃,有利于萃取实验的进行;同时,加入的正辛醇与TritonX-100对痕量铁起到了协同萃取作用.在优化了的实验条件下,进行了痕量铁的分析,检出限为0.02mg·L-1,加标回收率为97.4%~101.6%,应用于自来水及酒类样品中痕量铁的测定,结果满意.  相似文献   

20.
Y Michigami  K Fujii  K Ueda  Y Yamamoto 《The Analyst》1992,117(12):1855-1858
A simple ion-chromatographic method has been developed for the determination of trace amounts of thiocyanate in human saliva and urine. Thiocyanate separation and detection were carried out on an ODS column coated with cetyldimethylamine and by an ultraviolet detector, respectively. Citrate solution (1 mmol l-1) was used as the mobile phase. Thiocyanate was clearly separated from many organic and inorganic anions found in saliva and urine samples. The analytical results obtained by the proposed method agreed with those of the Fe(3+)-thiocyanate spectrophotometric method. Thiocyanate concentrations in the saliva and urine of smokers were found to be significantly higher than those of non-smokers.  相似文献   

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