A simple and sensitive method for the determination of trace amount of yttrium by solid-phase spectrophotometry has been studied. Yttrium can form a 1 : 1 complex with bromopyrogallol red (BPR) on resin, which was det...A simple and sensitive method for the determination of trace amount of yttrium by solid-phase spectrophotometry has been studied. Yttrium can form a 1 : 1 complex with bromopyrogallol red (BPR) on resin, which was determined directly at 605 nm, pH=6.5. It has a highly sensitivity (epsilon = 6.3 x 10(6)) which is 300-fold higher than the corresponding spectrophotometry in solution. The method was applied to the determination of yttrium in churchite.展开更多
Prior to formation of the micelles of cationic surfactant (CSF), bromopyrogallol red (BPR) could exist in the forms of both monomer and oligomer After that, however, only BPR monomer existed. Nonionic surfactant OP-10...Prior to formation of the micelles of cationic surfactant (CSF), bromopyrogallol red (BPR) could exist in the forms of both monomer and oligomer After that, however, only BPR monomer existed. Nonionic surfactant OP-10 favoured the oligomerization of BPR monomer. The mixed micellar media prepared by mixing CSF and OP-10 in an appropriate ratio could be used for the sensitive and selective determination of Mo in Mo/W binary mixtures.展开更多
Four simple, sensitive and accurate spectrophotometric methods have been developed for the determination of some calcium channel blockers: Amlodipine besylate (ADB), Diltiazem hydrochloride (DTZ) and Verapamil hydroch...Four simple, sensitive and accurate spectrophotometric methods have been developed for the determination of some calcium channel blockers: Amlodipine besylate (ADB), Diltiazem hydrochloride (DTZ) and Verapamil hydrochloride (VPM) in pharmaceutical formulations. These methods based on formation ion pair complexes with Sulfochlorophenol-S (SCPS), Bromopyrogallol red (BPR), Eriochromecyanine- R (ECC) and Pyrocatechol violet (PCV) in acidic medium. The colored products are extracted with chloroform and measured spectrophoto- metrically at 462, 600, 440 and 442 for ECC, SCPS, BPR and PCV, respectively. Beer’s low was obeyed in the concentration range, for ECC: 25 - 175 μg·ml-1, 50 - 150 μg·ml-1 or 100 - 250 μg·ml-1, for SCPS: 300 - 800 μg·ml-1, 200 - 700 μg·ml-1 or 100 - 550 μg·ml-1, for BPR: 50 - 400 μg·ml-1, 200 - 700 μg·ml-1 or 200 - 700 μg·ml-1 for VPM, DTZ or ADB, respectively and for PCV: 50 - 250 μg·ml-1 for VPM or 200 - 500 μg·ml-1 for DTZ with molar absorptivity, for ECC: 2.2 × 104, 2.1 × 104, 1.6 × 104 L·mol-1·cm-1, for SCPS: 3.8 × 103, 5.6 × 103, 8.1 × 103 L·mol-1·cm-1, for BPR: 11 × 103, 4.8 × 103, 6.9 × 103 L·mol-1·cm-1 for VPM, DTZ or ADB, respectively and for PCV: 19.5 × 103 L·mol-1·cm-1 for VPM and 6.6 × 103 L·mol-1·cm-1 for DTZ and relative standard deviation, for ECC: 0.76%, 0.86%, 0.46%, for SCPS: 0.94%, 0.96%, 0.86%, for BPR: 0.96%, 0.95%, 0.55% for VPM, DTZ or ADB, respectively and for PCV: 0.81% for VPM and 0.65% for DTZ. These methods have been successfully applied for the assay of drug in pharmaceutical formulations. No interference was observed from common pharmaceutical adjuvants. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.展开更多
A sensitive method is described for the determination of trace antimony based on the antimony-bromopyrogallol red (BPR) adsorption at a carbon paste electrode (CPE). Three steps were involved in the overall analysis: ...A sensitive method is described for the determination of trace antimony based on the antimony-bromopyrogallol red (BPR) adsorption at a carbon paste electrode (CPE). Three steps were involved in the overall analysis: preconcentration,reduction and stripping. Optimal conditions were found to be an electrode containing 25% paraffin oil and 75% high purity graphite powder as working electrode;a 0.10 mol/L HCl solution containing 40 μmol/L BPR as accumulation medium;a 0.20 mol/L HCl solution as reduction and stripping electrolyte;accumulation time,150 s;reduction potential and time,-0.50 V,60 s;scan range from -0.50 to 0.20 V. Interferences by other ions were studied as well. The detection limit was found to be 0.5 nmol/L for 150 s preconcentration. The linear range was from 1.0 nmol/L to 0.50 μmol/L. Application of the proposed method to the determination of antimony in water and human hair samples gave good results.展开更多
基金This research was financially supported by a grant from the KJCXGC-1 of NWNU,China.]
文摘A simple and sensitive method for the determination of trace amount of yttrium by solid-phase spectrophotometry has been studied. Yttrium can form a 1 : 1 complex with bromopyrogallol red (BPR) on resin, which was determined directly at 605 nm, pH=6.5. It has a highly sensitivity (epsilon = 6.3 x 10(6)) which is 300-fold higher than the corresponding spectrophotometry in solution. The method was applied to the determination of yttrium in churchite.
文摘Prior to formation of the micelles of cationic surfactant (CSF), bromopyrogallol red (BPR) could exist in the forms of both monomer and oligomer After that, however, only BPR monomer existed. Nonionic surfactant OP-10 favoured the oligomerization of BPR monomer. The mixed micellar media prepared by mixing CSF and OP-10 in an appropriate ratio could be used for the sensitive and selective determination of Mo in Mo/W binary mixtures.
文摘Four simple, sensitive and accurate spectrophotometric methods have been developed for the determination of some calcium channel blockers: Amlodipine besylate (ADB), Diltiazem hydrochloride (DTZ) and Verapamil hydrochloride (VPM) in pharmaceutical formulations. These methods based on formation ion pair complexes with Sulfochlorophenol-S (SCPS), Bromopyrogallol red (BPR), Eriochromecyanine- R (ECC) and Pyrocatechol violet (PCV) in acidic medium. The colored products are extracted with chloroform and measured spectrophoto- metrically at 462, 600, 440 and 442 for ECC, SCPS, BPR and PCV, respectively. Beer’s low was obeyed in the concentration range, for ECC: 25 - 175 μg·ml-1, 50 - 150 μg·ml-1 or 100 - 250 μg·ml-1, for SCPS: 300 - 800 μg·ml-1, 200 - 700 μg·ml-1 or 100 - 550 μg·ml-1, for BPR: 50 - 400 μg·ml-1, 200 - 700 μg·ml-1 or 200 - 700 μg·ml-1 for VPM, DTZ or ADB, respectively and for PCV: 50 - 250 μg·ml-1 for VPM or 200 - 500 μg·ml-1 for DTZ with molar absorptivity, for ECC: 2.2 × 104, 2.1 × 104, 1.6 × 104 L·mol-1·cm-1, for SCPS: 3.8 × 103, 5.6 × 103, 8.1 × 103 L·mol-1·cm-1, for BPR: 11 × 103, 4.8 × 103, 6.9 × 103 L·mol-1·cm-1 for VPM, DTZ or ADB, respectively and for PCV: 19.5 × 103 L·mol-1·cm-1 for VPM and 6.6 × 103 L·mol-1·cm-1 for DTZ and relative standard deviation, for ECC: 0.76%, 0.86%, 0.46%, for SCPS: 0.94%, 0.96%, 0.86%, for BPR: 0.96%, 0.95%, 0.55% for VPM, DTZ or ADB, respectively and for PCV: 0.81% for VPM and 0.65% for DTZ. These methods have been successfully applied for the assay of drug in pharmaceutical formulations. No interference was observed from common pharmaceutical adjuvants. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.
文摘A sensitive method is described for the determination of trace antimony based on the antimony-bromopyrogallol red (BPR) adsorption at a carbon paste electrode (CPE). Three steps were involved in the overall analysis: preconcentration,reduction and stripping. Optimal conditions were found to be an electrode containing 25% paraffin oil and 75% high purity graphite powder as working electrode;a 0.10 mol/L HCl solution containing 40 μmol/L BPR as accumulation medium;a 0.20 mol/L HCl solution as reduction and stripping electrolyte;accumulation time,150 s;reduction potential and time,-0.50 V,60 s;scan range from -0.50 to 0.20 V. Interferences by other ions were studied as well. The detection limit was found to be 0.5 nmol/L for 150 s preconcentration. The linear range was from 1.0 nmol/L to 0.50 μmol/L. Application of the proposed method to the determination of antimony in water and human hair samples gave good results.