The present paper describes the preparation of new organic reagent 2-[2-（6-chloro benzothiazolyl） azo]-resorcinol （6-CIBTAR = LH2） and used for the spectrophotometric determination of traces microgram amount of ni...The present paper describes the preparation of new organic reagent 2-[2-（6-chloro benzothiazolyl） azo]-resorcinol （6-CIBTAR = LH2） and used for the spectrophotometric determination of traces microgram amount of nickel （II） and copper （II） was found to form Ni（II）-CIBTAR at pH 7.5 giving a green coloured complex with maximum absorption at wavelength 636 nm and copper （II） was found to from Cu（II）-CIBTAR at pH 6.5 giving green bluish coloured complex with maximum absorption at wavelength 648 nm. The molar absorptivity （~） of the complexes are 0.3695 ~ 104 L.moll-cml and 0.3933 ~ 154 L＇mol＇l.cm1 for Ni（II） and Cu（II） respectively. Calibration curves for the determination of nickel（II） and copper （II） conformed to beers law over the concentration rang of （1-20） μg.mL-1. The DL （detection limit）, RSD （relative standard deviations）, RE （relative errors） and recovery for Ni（II） and Cu（II） complexes were found to be D.L = 0.45, 0.61; R.S.D% = 1.81, 2.04; Erei% = 1.3, 0.86 and Re% = 98.7, 99.14 respectively. The analytical data show the metal to reagent ratio （mole ratio method; M：L） in Ni（II） and Cu（II） complexes are 1：2.展开更多
A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At ...A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.展开更多
Nickel(II) reacts with 2-acetylpyridine-4-methyl-3-thiosemicarbazone (APMT) and forms a yellow colored complex, which was extracted into n-hexanol from sodium acetate and acetic acid buffer at pH 6.0. The absorbance v...Nickel(II) reacts with 2-acetylpyridine-4-methyl-3-thiosemicarbazone (APMT) and forms a yellow colored complex, which was extracted into n-hexanol from sodium acetate and acetic acid buffer at pH 6.0. The absorbance value of the Ni(II)-APMT complex was measured at different intervals of time at 375 nm to ascertain the time stability of the complex. The extraction of the complex into the solvent was instantaneous and stable for more than 72 hrs. The system obeyed Beer’s law in the concentration range of 0.235 - 2.43 μg·ml–1 of nickel(II), with an excellent linearity and a correlation coefficient of 0.999. The molar absorptivity and Sandell’s sensitivity of the extracted species were found to be 2.16 × 104 L mol–1 ·cm–1 and 0.003 μg·cm–2 at 375 nm, respectively. Hence a detailed study of the extraction of nickel(II) with APMT has been undertaken with a view to developing a rapid and sensitive extractive spectrophotometric method for the determination of nickel(II) when present alone or in the presence of diverse ions which are usually associated with nickel(II) in environmental matrices like soil and industrial effluents. Various standard alloy samples (CM 247 LC, IN 718, BCS 233, 266, 253 and 251) have been tested for the determination of nickel for the purpose of validation of the present method. The results of the proposed method are comparable with those from atomic absorption spectrometry and were found to be in good agreement.展开更多
文摘The present paper describes the preparation of new organic reagent 2-[2-（6-chloro benzothiazolyl） azo]-resorcinol （6-CIBTAR = LH2） and used for the spectrophotometric determination of traces microgram amount of nickel （II） and copper （II） was found to form Ni（II）-CIBTAR at pH 7.5 giving a green coloured complex with maximum absorption at wavelength 636 nm and copper （II） was found to from Cu（II）-CIBTAR at pH 6.5 giving green bluish coloured complex with maximum absorption at wavelength 648 nm. The molar absorptivity （~） of the complexes are 0.3695 ~ 104 L.moll-cml and 0.3933 ~ 154 L＇mol＇l.cm1 for Ni（II） and Cu（II） respectively. Calibration curves for the determination of nickel（II） and copper （II） conformed to beers law over the concentration rang of （1-20） μg.mL-1. The DL （detection limit）, RSD （relative standard deviations）, RE （relative errors） and recovery for Ni（II） and Cu（II） complexes were found to be D.L = 0.45, 0.61; R.S.D% = 1.81, 2.04; Erei% = 1.3, 0.86 and Re% = 98.7, 99.14 respectively. The analytical data show the metal to reagent ratio （mole ratio method; M：L） in Ni（II） and Cu（II） complexes are 1：2.
文摘A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.
文摘Nickel(II) reacts with 2-acetylpyridine-4-methyl-3-thiosemicarbazone (APMT) and forms a yellow colored complex, which was extracted into n-hexanol from sodium acetate and acetic acid buffer at pH 6.0. The absorbance value of the Ni(II)-APMT complex was measured at different intervals of time at 375 nm to ascertain the time stability of the complex. The extraction of the complex into the solvent was instantaneous and stable for more than 72 hrs. The system obeyed Beer’s law in the concentration range of 0.235 - 2.43 μg·ml–1 of nickel(II), with an excellent linearity and a correlation coefficient of 0.999. The molar absorptivity and Sandell’s sensitivity of the extracted species were found to be 2.16 × 104 L mol–1 ·cm–1 and 0.003 μg·cm–2 at 375 nm, respectively. Hence a detailed study of the extraction of nickel(II) with APMT has been undertaken with a view to developing a rapid and sensitive extractive spectrophotometric method for the determination of nickel(II) when present alone or in the presence of diverse ions which are usually associated with nickel(II) in environmental matrices like soil and industrial effluents. Various standard alloy samples (CM 247 LC, IN 718, BCS 233, 266, 253 and 251) have been tested for the determination of nickel for the purpose of validation of the present method. The results of the proposed method are comparable with those from atomic absorption spectrometry and were found to be in good agreement.
