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1.
75–300ng of bismuth in a sample mass of 20mg of silver can be determined spectrophotometrically in a nitric acid medium (0.18molL–1) with Semi-Xylenol Orange as chromogenic agent. Its selectivity is realized by using less toxic reagents in very small amounts to mask some of the interfering impurity cationic species while the matrix effect is negligible. The conditional formation constant of the colored chelate formed was found to be lgKf=3.1. It exhibits a maximum at 540nm with a molar absorptivity of 4.2×104Lmo1–1cm–1. The linear regression equation for this determination is A=0.022+0.0018C, where C stands for the concentration of Bi (ng per 0.5mL) with a correlation coefficient of 0.9873. The RSD at the level of 200ng of Bi (n=10) was found to be 5%.  相似文献   

2.
A spectrophotometric method for the selective determination of Al(III) in the presence of Be and Ln (lanthanide) cations is proposed. It is based on the selective reaction of SXO (Semi-Xylenol Orange) with Al(III) at pH 2.6. The presence of 8%v/v of 1,2-ethanediol serves to stabilize the chelate formed by heating at 100°C for 5min. 0.5mg each of Be(II), Ce(III), La(III), 4mg of Mn(II), 1.2mg of Pb(II), 1mg of Tl(I), 40mg each of Ca(II) and Mg(II) and 1.9mg of sodium dihydrogen phosphate are tolerable. A ligand buffer of HEDTA-Pb is incorporated to further enhance the selectivity of the color reaction. Under the specified conditions SXO reacts with Al(III) to form a 1:1 chelate. Its molar absorptivity at 526nm was found to be 3.3×104Lmol–1cm–1. The linear regression equation for 2–20µg of Al(III) is A=0.04458C+0.0112 (where C stands for the concentration of Al(III), µg per 25mL) and correlation coefficient =0.9988. The RSD at the level of 10µg (n=10) and LOQ were found to be 3.5% and 2µg, respectively.  相似文献   

3.
Nan Zhou 《Mikrochimica acta》2003,142(1-2):89-94
 A spectrophotometric method for the selective determination of Al(III) in the presence of Be and lanthanide cations is proposed. It is based on the selective reaction of Semi-Xylenol Orange with Al(III) at pH 2.6. The presence of 8% v/v of 1,2- ethanediol serves to stabilize the chelate formed by heating for 5 min at 100 °C. 0.5 mg each of Be(II), Ce(III), La(III), 4 mg of Mn(II), 1.2 mg of Pb(II), 1 mg of Tl(I), 40 mg each of Ca(II) and Mg(II) and 1.9 mg of sodium dihydrogen phosphate are tolerable. A ligand buffer of HEDTA-Pb is incorporated to further enhance the selectivity of the color reaction. Under the specified condition Semi-Xylenol Orange reacts with Al(III) to form a 1:1 chelate, its molar absorptivity at 526 nm was found to be 3.3 × 104 L mol−1 cm−1. The linear regression equation for 2–20 μg of Al(III) is A = 0.04458C + 0.0112 (here C stands for the concentration of Al(III), μg per 25 mL), and correlation coefficient γ = 0.9988. The RSD at a level of 10 μg (n = 10) and LOQ were found to be 3.5% and 2 μg respectively. Author for correspondence. E-mail: weston@online.sh.cn Received November 15, 2002; accepted February 11, 2003 Published online June 13, 2003  相似文献   

4.
报道了以1-苯基-3-甲基-4-苯甲酰基-吡唑酮[5](PMBP)为化学改进剂的ETV-ICP-AES测定痕量钪的新方法.详细研究了金属螯合物在石墨炉内的形成、挥发及其影响因素;发现过量PMBP的存在有利于该螯合物的形成,并定量蒸发/传输至等离子体中.在优化的实验条件下,钪的检出限为0.3ng/mL,相对标准偏差为2.4%(c=0.1μg/mL,n=7).本法已用于标准参考物机动车尾气尘粒中钪的测定,获得了满意的结果.  相似文献   

5.
聚乙烯醇存在下钼酸盐和罗丹明B光度法测定钪   总被引:4,自引:0,他引:4  
在聚乙烯醇存在下,钪相杂多酸和罗丹明B(RB)形成离子缔合物,其最大吸收位于570nm,表观摩尔吸光系数ε值为5.62×10^5L.mol^-1.cm^-1,服从比耳定律范围0-1.0μgSc/25mL,检出限1.1ng/mL(n=9),考察了50多种外来离子影响,缔合物的摩尔组成为Sc:Mo:RB=1:12:6,方法用于地质样品中钪的分析,结果满意。  相似文献   

6.
A new method is proposed for the determination ofo-Cresol Red in Xylenol Orange and semi-Xylenol Orange by third-order derivative spectrophotometry at 491 nm in a medium of 0.09 mol/1 sulphuric acid. A linear relationship exists between d3A/d3 and theo-Cresol Red concentration (1–12 g/ml), with a standard deviation of 0.11 g/ml (n = 8) for 10 g/ml ofo-Cresol Red.Presented at the 34th IUPAC Conference (1993)  相似文献   

7.
 This study describes a rapid and sensitive spectrophotometric method for the determination of trace amounts of selenium, using starch and iodine as chromogenic reagents. The proposed method is based on the reaction of selenium with potassium iodide in an acidic medium to liberate iodine. This reacts with starch to form a blue colored species with an absorption maximum of 570 nm. Beer’s Law was obeyed in the range of 2–12 μg of selenium. The molar absorptivity and Sandell’s sensitivity were found to be 1.40×104 L mol−1 cm−1 and 5.45×10−3 μg cm−2 respectively. The proposed method was successfully applied to determine selenium in a sample of natural water, polluted water, soil sludge, biological samples and human hair. Correspondence: Department of Studies in Chemistry, Managalore University, Mangalagangothri, Karnataka, India. e-mail: nbadiadka@yahoo.co.uk Received August 2, 2002; accepted October 29, 2002  相似文献   

8.
《Analytical letters》2012,45(23-24):2231-2242
Abstract

A simple solvent extraction and spectrophotometric method for the determination of micro amount of phosphate (PO4) is described. Phosphate is selectively separated from associated elements by reacting it with calcium and extracting excess calcium with N-phenylbenzohydroxamic acid (PBHA) at pH 11.3. The excess calcium was determined in ultra-violet and visible region and hence the phosphate content was calculated. The Beer's law is obeyed in the range 0.5 ? 10.0 ppm at 340 nm and 0.25 - 8.0 ppm at 560 nm of phosphate for a fixed amount of calcium (20.0 ppm). These results are also compared with those obtained by atomic absorption spectrophotometry. The method has been applied for the determination of phosphate in pharmaceutical and other samples.  相似文献   

9.
Kiciak S 《Talanta》1990,37(12):1197-1203
An extraction method based on the butanol—water system is used in an improved spectrophotometric determination of Xylenol Orange (XO), Semi-Xylenol Orange (SXO) and Cresol Red (CR) in mixtures. Small amounts of SXO in the presence of much greater amounts of XO, and small amounts of XO in the presence of large amounts of SXO can be determined with good accuracy after extractive separation of the compound to be determined, from the bulk of the other components of the mixture.  相似文献   

10.
丁基罗丹明B—钼酸盐光度法连续测定铈和钪   总被引:4,自引:0,他引:4  
王加林  徐其亨 《分析化学》1996,24(3):344-347
在聚乙烯醇(PVA)存在下,丁基罗丹明B(BRB)分别与铈钼、钪钼杂多酸络阴离子形成离子缔合物,其最大吸收均位于570nm,表面摩尔吸光度分别为εCe=3.96×10^6L.mol^-1.cm^-1,εSc=4.71×10^5L.mol^-1.cm^-1,服从比耳定律范围分别为0-24μg/L Ce和0-60μg/LSc,测定极限为Ce1.0μg/L(n=12)和Sc1.9μg/L(n=10),对  相似文献   

11.
《Analytical letters》2012,45(13-14):1349-1358
Abstract

1-Hydroxy-2-carboxyanthraquinone reacts with magnesium in ethanol-water mixtures to form a red complex having an absorption maximum at 490 nm in alkaline medium. A detailed study of the characteristics of this complex has been carried out and a spectrophotometric method for the determination of magnesium at the 0.4–4.0 μg ml?1 level is proposed. The method has been sensitized by employing first derivative spectrophotometry. By the use of the derivative approach magnesium can be determined between 0.08–0.40 μg ml?1. Statistical analysis of the results is also described.  相似文献   

12.
钪—P507萃取色层分离的研究及其应用   总被引:1,自引:1,他引:1  
  相似文献   

13.
电感耦合等离子体原子发射光谱法测定镁钪合金中钪   总被引:1,自引:0,他引:1  
提出了采用电感耦合等离子体原子发射光谱法测定镁钪合金中钪的含量。以盐酸(1+1)溶液和过氧化氢溶解样品,选择波长为361.384nm的谱线作为钪的分析线。钪的发射强度与其质量浓度在20.00mg·L~(-1)以内呈线性关系,方法的检出限(3s)为2.9×10~(-1)mg·L~(-1)。方法用于镁钪合金样品分析,加标回...  相似文献   

14.
在一定的条件下,对氯偶氮氯膦(CPA_pC)与等量的15种单一稀土所形成的络合物具有彼此相似的吸光度值。且该试剂也是钪的灵敏显色剂。据此分析特性,连续测定了矿石中稀土总量与钪,分析结果与标准数据基本相符。  相似文献   

15.
催化动力学光度法测定微量硅   总被引:1,自引:0,他引:1  
  相似文献   

16.
本文根据亚硝酸根与对氨基苯磺酸、H酸在酸性介质中进行的重氮偶联反应,提出了一个测定痕量亚硝酸根的分光光度新体系。最大吸收波长为520nm,摩尔吸光系数为3.1×10 ̄4L/mol·cm,亚硝酸根浓度在0~1.2μg/mL范围内符合比耳定律.用于水样中亚硝酸根的分析,测定结果与经典的α-萘胺法一致。  相似文献   

17.
《Analytical letters》2012,45(10):2223-2232
Abstract

A simple, sensitive and selective spectrophotometric method has been developed for the determination of thyroxine sodium. It is based on a reaction with excess of p-benzoquinone in ethanol (95%) whereby 1:1 (thyroxine sodium: quinone) coloured product is obtained, which has an apparent molar absorptivity of 2.911 × 103 1mol?1 and Beer's law is obeyed over the range of 40–200 μg.ml?1. When applied to tablets labelled to contain 100 μg, the proposed method gave mean recoveries of 99,13 ± 0.36% for different amounts of added authentic drug.  相似文献   

18.
用金钨杂多酸和耐尔蓝光度法测定纳克量金   总被引:3,自引:2,他引:3  
在阿拉伯胶存在下,金与钨酸钠和耐尔蓝(NB)形成离子缔合物,它的最大吸收位于580nm,表观摩尔吸光系数ε值为2.38×10^7L·mol^-1·cm^-1,体系至少稳定24h。金量在0 ̄4.4μg/L范围内服从比尔定律,检测限(3σ)为0.069μg/L(n=12),对4.0μg/L Au(Ⅲ)测定的相对标准偏差为1.9%(n=11),离子缔合物的摩尔比为Au(Ⅲ):NB=1:3。考察了40多种  相似文献   

19.
《Analytical letters》2012,45(3):621-633
Abstract

A spectrophotometric method is described for the determination of neomycin based on the reaction with 2,4-dinitrofluorobenzene. the best conditions for the reaction were obtained by using 0.02 M borate buffer (pH 9.0) as diluent, under ambient conditions after 50 minutes of reaction.  相似文献   

20.
《Analytical letters》2012,45(4):805-815
Abstract

This paper describes a kinetic spectrophotometric method for the determination of L‐ascorbic acid (AA) and thiols (RSH). Absorbance of Fe(II)‐phen complex formed during the reaction of AA or RSH with Fe(III)‐phen was continuously measured at 510 nm by double‐beam spectrophotometer with flow cell. For determination some thiols, the catalytic effect of Cu2+ ions was used. AA and RSH can be determined in concentration ranges from 4.0×10?6 to 4.0×10?5 M and from 8.0×10?6 to 8.0×10?5 M, respectively. The applicability of the proposed method was demonstrated by determination of chosen compounds in pharmaceutical dosage forms.  相似文献   

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