HPLC Determination of some antibilharzial antimonials by extraction of antimony

The antimonial drug (antimony potassium tartrate, antimony piperazine tartrate or antimony lithium thiomaleate) in aqueous solution or biological fluid is treated with sodium diethyldithiocarbamate in the presence of a suitable masking reagent, the pH is adjusted to 9 +/- 0.5. and the antimony complex extracted with n-hexane and determined by reversed-phase HPLC with an ODS column and detection at 254 nm. The limits of detection are 20 ng (for antimony potassium tartrate and antimony lithium thiomaleate) and 16 ng (for antimony piperazine tartrate).     

Differential determination of antimony(III) and antimony(V) by solvent extraction-spectrophotometry with mandelic acid and Malachite Green, based on the difference in reaction rates

Highly sensitive and reproducible extraction-spectrophotometric methods for differential determination of antimony(III) and antimony(V) were investigated. It was found that antimony(III) reacts easily with mandelic acid to form a complex anion extractable into chlorobenzene with Malachite Green from weakly acidic media (pH 2.2-3.5) at room temperature, whereas antimony(V) reacts only slowly, and heating for 15 min at 45 degrees is needed to obtain maximum sensitivity. The significant difference between the rates of reaction of mandelic acid with antimony(III) and antimony(V) was applied to the differential determination of these two species. The calibration graph was linear over the range 0.15-6.0 mug for antimony(III), and 0.20-10 mug for antimony(V).     

Speciation of Antimony in Leaching Solution in Contact with Plastic by Novel Liquid-Liquid Microextraction and Graphite Furnace Atomic Absorption Spectrometry

A novel, simple, sensitive, and efficient method for the speciation of inorganic antimony by dispersive liquid–liquid microextraction (DLLME) combined with graphite furnace atomic absorption spectrometry (GF-AAS) is reported. The method uses a hydrophobic complex of antimony(III) with a new chelating agent, 1,2,6-hexanetriol trithioglycolate, at neutral pH. The complex was extracted into the organic phase, whereas antimony(V) remained in aqueous solution. The concentration of antimony(V) was obtained by subtracting the antimony(III) concentration from the total antimony concentration following the reduction of antimony(V) to antimony(III) by L-cysteine. The pH, extraction and dispersive solvents and volumes, and concentration of 1,2,6 -hexanetriol trithioglycolate were optimized. Under the optimized conditions, the analytical curve was linear from 0.26 to 3.2 micrograms per liter with a limit of detection of 27.0 nanograms per liter for antimony(III). The relative standard deviation was 6.8 percent at 0.52 microgram per liter antimony(III) with an enrichment factor of twenty-six. The method was employed for the speciation of antimony in leaching solution in contact with plastic; and the recoveries in fortified samples were between 94.2 and 118.0 percent.     

Selective separation and differential determination of antimony(III) and antimony(V) by solvent extraction with N-benzoyl-N-phenylhydroxylamine and graphite-furnace atomic-absorption spectrometry using a matrix-modification technique

If copper is used as a matrix modifier for the determination of antimony, the ashing temperature for antimony in aqueous solution and a BPHA-CHCl(3) extract can be raised to 1300 degrees and 1100 degrees , respectively. A selective procedure for separating antimony(III) from antimony(V) by extraction with BPHA in chloroform is described, along with the conditions for preserving trace antimony in water samples. The recommended method has been applied satisfactorily to the determination of antimony(III) and antimony(V) in various types of water at sub-ng/ml levels.     

A Coulometric Analysis Method and an Ion-exclusion Chromatographic Method for the Determination of Antimony(V) in Large Excess of Antimony(III)

A coulometric analysis method and an ion-exclusion chromatographic method were developed for the determination of antimony(V) in a large excess of antimony(III). Antimony(V) reacted with potassium iodide in a high concentration hydrochloric acid; the liberated iodine was determined by the standard-addition method using coulometrically generated iodine. Using a Dionex ICE-AS1 ion-exclusion column, antimony(V) was eluted with 40 mmol/L sulfuric acid; on the other hand, antimony(III) was strongly retained on the column. The content, expressed as the amount ratio of antimony(V) to antimony(III), was 0.035% in a 10 g/kg antimony(III) solution prepared from an antimony(III) oxide reagent by the coulometric analysis method and 0.036% in a 1 g/kg antimony(III) solution prepared from the same antimony(III) oxide by the ion-exclusion chromatographic method. The results of both methods were in good agreement with each other. The detection limit of antimony(V) in antimony(III) oxide by the former method was 0.004% of antimony(III), and that by the latter method was 0.002% of antimony(III).     

Selective determination of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone by atomic-absorption spectrometry with a carbon-tube atomizer

The extraction behaviour of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone in organic solvents has been investigated by means of frameless atomic-absorption spectrophotometry with a carbon-tube atomizer. The selective extraction of antimony(III) and differential determination of antimony(III) and antimony(V) have been developed. With ammonium pyrrolidinedithiocarbamate and methyl isobutyl ketone, when the aqueous phase/solvent volume ratio is 50 ml/10 ml and the injection volume in the carbon tube is 20 mul, the sensitivity for antimony is 0.2 ng/ml for 1% absorption. The relative standard deviations are ca. 2%. Interferences by many metal ions can be prevented by masking with EDTA. The proposed methods have been applied satisfactorily to determination of antimony(III) and antimony(V) in various types of water.     

Electrothermal atomic-absorption spectrometry of antimony by use of a molybdenum micro-tube atomizer

Electrothermal atomization of antimony has been investigated to clarify the atomization characteristics and interferences from diverse elements, for accurate determination of traces of antimony. Thiourea served to lower the atomization temperature of antimony and to improve the sensitivity. Germanium and phosphoric acid were found to have a pronounced effect on atomization of antimony. The interference of various elements was suppressed in the presence of thiourea. A method involving extraction for determining antimony in metallurgical and geological samples is described.     

Determination of antimony in lead-zinc concentrates and other smelter products by atomic absorption spectrometry after extraction with di-isopropyl ether and reductive stripping

Several papers have appeared in the literature describing the determination of antimony, where antimony(V) is extracted into the organic phase and the organic solutions directly analyzed by atomic absorption spectrometry (AAS). This paper describes a procedure where antimony from the organic solution is reductively stripped into an aqueous phase and analyzed for antimony by AAS. The advantage of the method for a routine process control laboratory is highlighted.     

A reactivation solution for a copperized cadmium column in the automatic determination of nitrate in natural waters

Atomic fluoreseace spectrometry (a.f.s.) with a non-dispersive system is combined with a hydride generation technique for the determination of antimony at the nanogram level. Fluorescence measurement is based on the reduction of antimony by either zinc or sodium borohydride, introduction of the stibine into the premixed argon (entrained air)-hydrogen flame, and excitation with an antimony electrodeless discharge lamp. The detection limits are 0.5 and 1.0 ng of antimony for zinc and sodium borohydride, respectively. The reagent blank for a 20-ml sample is ca. 5 ng of antimony for both reductants. Analytical working curves from peak-height or peak-area measurements are linear over ca. 4 orders of magnitude. Other hydride-forming elements and several metals, e.g. gold, nickel, palladium and platinum, interfere. The method gives satisfactory results for the determination of trace amounts of antimony in waste waters and lead.     

Speciation of antimony(III) and antimony(V) in cell extracts by anion chromatography/inductively coupled plasma mass spectrometry

An analytical method for the separation and quantification of Sb(III) and Sb(V) using anion chromatography with ICP-MS is presented. The optimum conditions for the separation of the antimony species were established with 15 mmol/L nitric acid at pH 6 as eluent system on a PRP-X100 column. The retention times for antimony(V) and antimony(III) were 85 s and 300 s with detection limits of 0.06 microg/L and 0.29 microg/L, respectively. The proposed method was applied to cell extracts of Leishmania donovani, which were incubated with antimony(III) and antimony(V). Some metabolism seemed to occur within the cells.     

氢化物发生-原子荧光光谱法同时测定水中砷和锑

建立在硝酸介质中用氢化物发生-原子荧光光谱法同时测定水中砷和锑的方法。优化了仪器工作条件、酸度、硼氢化钾及还原剂浓度。砷、锑的线性范围为0～10．0μg／L;检出限分别为0．02,0．01μg／L;测定结果的相对标准偏差分别为1．77％～3．72％,2．95％～4．87％（n=6）;加标回收率分别为98％106％,96％105％。该法操作简便,灵敏度高,快速,便于推广,适用于水中砷和锑的同时测定。     

Speciation of antimony(III) and antimony(V) in cell extracts by anion chromatography/ inductively coupled plasma mass spectrometry

An analytical method for the separation and quantification of Sb(III) and Sb(V) using anion chromatography with ICP-MS is presented. The optimum conditions for the separation of the antimony species were established with 15 mmol/L nitric acid at pH 6 as eluent system on a PRP-X100 column. The retention times for antimony(V) and antimony(III) were 85 s and 300 s with detection limits of 0.06 μg/L and 0.29 μg/L, respectively. The proposed method was applied to cell extracts of Leishmania donovani, which were incubated with antimony(III) and antimony(V). Some metabolism seemed to occur within the cells.     

Determination of antimony in lead, zinc concentrates and other smelter products by atomic-absorption spectrophotometry after separation by n-butyl acetate extraction of the chloro-complex

An extractive atomic-absorption spectrophotometric (AAS) procedure is developed for fast and accurate determination of up to 20 mug/g antimony in lead and zinc concentrates and other smelter products. The procedure involves digestion of the sample with potassium bisulphate and sulphuric acid, addition of hydrazine to reduce all antimony to Sb(III), reoxidation to Sb(V), extraction of the chloro-complex of antimony(V) with n-butyl acetate, and AAS analysis of the organic phase for antimony.     

A volumetric determination of arsenic and antimony in mixed manganese arsenide,antimonide and phosphide compounds

A procedure is described for the titrimetric determination, of arsenic and antimony without separation. Total combined arsenic and antimony were determined by reduction with tin(II) chloride and titration with permanganate; antimony is found by selective reduction with mercury(I) chloride and titration with permanganate. A precision of 0.1–0.2% was obtained for total combined arsenic and antimony, and approximately 1% for antimony alone (small amounts in the presence of large amounts of arsenic). The procedure was developed for and applied to the analysis of synthesized compounds of the type MnAs_1-xP_x and MnAs_1-ySb_y.     

Determination of arsenic and antimony in electrolytic copper by anodic stripping voltammetry at a gold film electrode

A simple procedure is described for the determination of arsenic and antimony in electrolytic copper. The copper is digested with nitric acid and copper is separated from arsenic and antimony by passing an ammoniacal solution of the sample through a column of Chelex-100 resin. After digestion with sulphuric acid and reduction to arsenic(III) and antimony(III) with sodium sulphite in 7 M sulphuric acid at 80°C, both arsenic and antimony are deposited at-0.30V and their total is determined by anodic stripping; antimony is then selectively deposited at -0.05 V for anodic stripping. The lower limits of determination are 56 ng As and 28 ng Sb per gram of copper; relative standard deviations (n = 5) are in the ranges 6.1–15.0% for 5.5—0.5 ppm arsenic in copper and 4.1–6.8% for 2.6—0.6 ppm antimony.     

Speciation Analysis of Antimony (III) and Antimony (V) by Flame Atomic Absorption Spectrometry After Separation/Preconcentration With Cloud Point Extraction

A sensitive and simple method for flame atomic absorption spectrometry (FAAS) determination of antimony species after separation/preconcentration by cloud point extraction (CPE) has been developed. When the system temperature is higher than the cloud point extraction temperature, the complex of antimony (III) with N-benzoyl-N-phenyhydroxylamine (BPHA) can enter the surfactant-rich phase, whereas the antimony (V) remains in the aqueous phase. Antimony (III) in surfactant-rich phase was analyzed by FAAS and antimony (V) was calculated by subtracting of antimony (III) from the total antimony after reducing antimony (V) to antimony (III) by L-cysteine. The main factors affecting the cloud point extraction, such as pH, concentration of BPHA and Triton X-114, equilibration temperature and time, were investigated systematically. Under optimized conditions, the detection limits (3σ) were 1.82 ng mL⁻¹ for Sb(III) and 2.08 ng mL⁻¹ for Sb(total), and the relative standard deviations (RSDs) were 2.6% for Sb(III) and 2.2% for Sb(total). The proposed method was applied to the speciation of antimony species in artificial seawater and wastewater, and recoveries in the range of 95.3–106% were obtained by spiking real samples. This technique was validated by means of reference water materials and gave good agreement with certified values.     

Spectrophotometric determination of antimony with 3,5,7,4'-tetrahydroxyflavone (kaempferol)

A selective spectrophotometric method is described for determination of antimony with kaempferol. Microgram amounts of antimony can be determined by measurements at 420 run in 0.1M hydrochloric acid. The molar absorptivity is 1.09 x 10(4) at 420 nm and the optimum range for accurate determination is 1.9-7.8 ppm of antimony.     

Speciation of Antimony in Soils and Sediments by Liquid Chromatography–Hydride Generation–Atomic Fluorescence Spectrometry

The methodology for antimony speciation was optimized for liquid chromatography coupled to hydride generation – atomic fluorescence spectrometry. An anion exchange column was employed with isocratic elution. Ammonium tartrate was shown to be the optimum mobile phase and extracting solution for this analysis. The highest efficiency and resolution for the antimony species was achieved using 5 percent methanol in 300 millimoles per liter ammonium tartrate acidified with hydrochloric acid to pH 4.5. The retention times of antimony(V), trimethylantimony, and antimony(III) were 2.6, 3.9, and 5.2 minutes, respectively. The calibration curves were linear with limits of detection of 0.1, 0.2, and 0.43 microgram per liter for antimony(III), antimony(V), and trimethylantimony, respectively. The precision, evaluated by the relative standard deviation, ranged from 1.2 to 5.3 percent. The average recovery from these environmental samples by a single-step procedure was approximately 26 percent. The results also revealed that the correlation between the sum of each species by the single-step procedure and total digestion was significant for the investigated soils and sediments.     

Antimony speciation by inductively coupled plasma mass spectrometry using solid phase extraction cartridges

A novel and simple method for inorganic antimony speciation is described based on selective solid phase extraction (SPE) separation of antimony(III) and highly sensitive inductively coupled plasma mass spectrometric (ICP-MS) detection of total antimony and antimony(V) in the aqueous phase of the sample. Non-polar SPE cartridges, such as the Isolute silica-based octyl (C8) sorbent-containing cartridge, selectively retained the Sb(III) complex with ammonium pyrrolidine dithiocarbamate (APDC), while the uncomplexed Sb(V) remained as a free species in the solution and passed through the cartridge. The Sb(III) concentration was calculated as the difference between total antimony and Sb(V) concentrations. The detection limit was 1 ng L(-1) antimony. Factors affecting the separation and detection of antimony species were investigated. Acidification of samples led to partial or complete retention of Sb(V) on C8 cartridge. Foreign ions tending to complex with Sb(III) or APDC did not interfere with the retention behavior of the Sb(III)-APDC complex. This method has been successfully applied to antimony speciation of various types of water samples.     

Redox substoichiometry in isotope dilution analysis

Radiometric titration of antimony(III) with potassium bromate in hydrochloric acid media using the standard series method provided much valuable informations on the titration errors which depended on the concentrations of the acid and antimony(III). The hydrochloric acid concentrations between 2.5 and 3.0M were found to be optimum for the oxidation of antimony(III) amounts of 4 μg or less. Under these optimum reaction conditions the redox substoichiometric isotope dilution analysis was applied to the determination of antimony in metallic zinc and the satisfactory results were obtained, without the separation of matrix element. Also, the merits of various oxidizing agents hitherto studied for the quantitative oxidation of antimony(III) were compared and discussed.