Gas Chromatography-atomic Absorption Research Articles

Determination of antimony and the differential determination of antimony(III) and antimony(V) by ICP-AES and high-resolution ICP-MS with a hydride generation technique

Simple methods for the chemical speciation of antimony and organotin compounds were developed by atomic spectroscopy. Antimony was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and high-resolution inductively coupled plasma mass spectrometry (ICP-MS) with a hydride generation technique. Stibine generated with sodium tetrahydroborate(III) (SBH) in a mixing coil was separated from solution with a spiral tube in a closed vessel. The antimony contents of River Arakawa were determined by the present methods. Antimony(III) and antimony(V) were determined differentially by ICP-AES and ICP-MS. Antimony(III) was determined at pH 5.5, while the total antimony was determined at pH 1.0 using potassium iodide as a prereductant. It was found by ICP-MS that the antimony(III) contents of River Arakawa increased while the antimony(V) contents decreased while descending down-stream. Tributyltin and triphenyltin in fish were determined by gas chromatography-atomic absorption spectrometry (GC-AAS) with hydride generation. Fish meat was homogenized in a hydrochloric acid solution of 8-quinolinol. The chlorides in fish were extracted into hexane. After the solvent had been converted to 2-propanol, the solution was applied to a Bondesil SCX solid sorbent. The organotin compounds were eluted with a methanol solution of hydrochloric acid and determined by GC-AAS after hydradization with SBH. The organotin chlorides are supposed to form ion-associates with 8-hydroquinolinium cation in a hydrochlic acid medium.

Speciation of tin, arsenic and antimony species by using hydride generation and reaction kinetics coupled with ICP-AES and ICP-MS

Tin was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and high resolution-inductively coupled plasma mass spectrometry (ICP-MS) with a hydride generation technique. Stannane generated with sodium tetrahydroborate(III) (SBH) was separated from solution with a spiral tube in a closed vessel. The tin content in marine materials was determined by the present methods. Antimony(III) and antimony(V) were determined by ICP-AES or ICP-MS using the pre-reduction of antimony with L-cysteine. Also, arsenic(III) and arsenic(V) were determined by ICP-MS combined with the pre-reduction of arsenic. Tributyltin and triphenyltin in marine sediments were determined by gas chromatography-atomic absorption spectrometry (GC-AAS) with hydride generation. The chlorides in sediments spiked with a hydrochloric acid solution of 8-quinolinol were extracted into toluene. After the solvent had been converted to ethanol, it was applied to a Bondesil SCX. The organotin compounds were eluted with a methanol solution of hydrochloric acid and determined by GC-AAS after hydridization.

Speciation of organotin compounds in marine sediments by capillary column gas chromatography-atomic absorption spectrometry coupled with hydride generation.

A method for speciation of organotin compounds in marine sediments by solvent extraction combined with hydride generation gas chromatography-atomic absorption spectrometry has been developed. Sediment samples spiked with tributyltin and triphenyltin chlorides were homogenized in hydrochloric acid. The chlorides were extracted twice into toluene. Recoveries of the organotin compounds from the spiked sediment samples were improved by the addition of 8-quinolinol. Tributyltin and triphenyltin chlorides form ion-associates with 8-quinolinol in aqueous hydrochloric acid. The method was optimized with respect to derivatization reactions and extraction conditions. Interferences from Sn(II/IV) and additional 13 ions were investigated. Recoveries of 84-100% for tributyltin and 86-100% for triphenyltin were achieved using this method. The detection limits obtained for tributyltin and triphenyltin chlorides were 95 and 145 pg, respectively, corresponding to a relative detection limit of 95 and 145 ng kg(-1) in the sediment.

In situ propylation of ionic organotin and organolead species in water samples – Extraction and determination of the resulting tetraorganometallic compounds by gas chromatography-atomic absorption spectrometry

In situ propylation of ionic organotin and organolead species in water samples – Extraction and determination of the resulting tetraorganometallic compounds by gas chromatography-atomic absorption spectrometry

In situ propylation of ionic organotin and organolead species in water samples - Extraction and determination of the resulting tetraorganometallic compounds by gas chromatography-atomic absorption spectrometry

An analytical method for the simultaneous in situ derivatization of organotin and organolead compounds in water samples is described. Propylated derivatives of the analytes formed directly in the aqueous medium by reaction with tetrapropylborate ions are extracted by hexane/pentane. The organic layer is dried and purified with sodium sulfate, concentrated by evaporation of the solvent, and injected into a coupled gas chromatography-atomic absorption spectrometry system. The organotin and organolead compounds are determined sequentially. The optimum parameters for the derivatization and extraction procedures of in situ butylation of organolead compounds developed earlier could be successfully applied to the in situ propylation.

Determination of Organotin Compounds in Fish by Gas Chromatography-Atomic Absorption Spectrometry Using 8-Quinolinol as a Complexing Agent

Recoveries of tributyltin and triphenyltin chlorides spiked in fish were improved by addition of 8-quinolinol. Fish samples spiked with tributyltin and triphenyltin chlorides were homogenized with hydrochloric acid. The chlorides were extracted twice into hexane. After centrifugation, a 2-propanol solution of the chlorides were adsorbed to Bondesil SCX and eluted with a methanol solution of 1 M hydrochloric acid. The chlorides were hydradized with an ethanol solution of sodium tetrahydroborate(III) and injected into a gas chromatography–atomic absorption spectrometer. Tributyltin and triphenyltin chlorides in an NIES Certified Reference Material (sea bass) were determined by the proposed procedure. The analytical results were close to the certified and reference values, respectively. Low recoveries were obtained when monobutyltin and dibutyltin chlorides were spiked with and without 8-quinolinol. Tributyltin and triphenyltin chlorides are supposed to form ion-associates with 8-quinolinol in an aqueous solution of hydrochloric acid. The detection limits (three times the signal-to-noise ratio) of tributyltin and triphenyltin chlorides were 105 and 165 pg, respectively.

Speciation of inorganic and organolead compounds by gas chromatography-atomic absorption spectrometry and the determination of lead species after pre-concentration onto diphenylthiocarbazone-anchored polymeric microbeads

Poly(EGDMA-HEMA) microbeads were prepared by suspension copolymerization of ethyleneglycol dimethacrylate (EGDMA) and hydroxyethylmethacrylate (HEMA) using poly(vinylalcohol), benzoyl peroxide and toluene as the stabilizer, the initiator, and the diluent, respectively. A chelating ligand, diphenylthiocarbazone (dithizone), was then attached. The microbeads were characterized by FT-IR and elemental analysis. The affinity microbeads containing 118.9 μmol dithizone g −1 polymer were used in the adsorption/desorption of some selected lead species, Pb(II), (CH 3) 2PbCl 2, (C 2H 5) 2PbCl 2, (CH 3) 3PbCl, and (C 2H 5) 3PbCl from aqueous media containing different amounts of these species (5–200 mg l −1) at different pH values, 2.0–8.0. Adsorption rates were high, and adsorption equilibrium was reached in approximately 45 min. The detection limits of the lead species onto the dithizone-anchored affinity microbeads from solutions containing a single species was 0.28 ng ml −1 for Pb(II), 0.12 ng ml −1 for (CH 3) 3PbCl, 0.24 ng ml −1 for (C 2H 5) 3PbCl, 0.18 ng ml −1 for (CH 3) 2PbCl 2 and 0.30 ng ml −1 for (C 2H 5) 2PbCl 2 on a weight basis for lead. The same behavior was observed during competitive adsorption that is adsorption from a mixture. The affinity order of the lead species was Pb(II)>(CH 3) 2PbCl 2>(CH 3) 3PbCl>(C 2H 5) 3PbCl>(C 2H 5) 2PbCl 2 for competitive adsorption. Dithizone-anchored microbeads were found to be suitable for repeated use of more than five cycles, without noticeable loss of adsorption capacity. For the speciation of organolead compounds, ionic alkyllead compounds were derivatized by n-butyl Grignard reagent and the speciation was performed using a gas chromatography-atomic absorption spectrometry coupled system. Detection limits were improved at least 180-fold with this preconcentration approach using the dithizone-anchored microbeads.

Determination of inorganic and organic mercury compounds by capillary gas chromatography coupled with atomic absorption spectrometry after preconcentration on dithizone-anchored poly(ethylene glycol dimethacrylate-hydroxyethylmethacrylate) microbeads

Poly(EGDMA-HEMA) microbeads were prepared by suspension polymerization of ethylene glycol dimethacrylate (EGDMA) and hydroxyethyl methacrylate (HEMA). Poly(vinyl alcohol), benzoyl peroxide and toluene were used as stabilizer, initiator, and diluent, respectively. A chelating ligand, dithizone, was then attached. The microbeads were characterized by FTIR spectrometers and elemental analysis. The affinity microbeads containing 118.9 μmol dithizone g −1 polymer were used for the adsorption/desorption of inorganic mercury [Hg], methyl mercury chloride [CH 3HgCl] and ethyl mercury chloride [C 2H 5HgCl] from aqueous media at concentrations in the range 5–1000 μg l −1 and various pH values (2.0–8.0). Adsorption rates were high, and adsorption equilibria were reached in about 30 min. The maximum adsorption of mercury species onto the dithizone-anchored microbeads from their individual solutions was 138 mg g −1 for Hg(II), 221 mg g −1 for CH 3HgCl and 207 mg g −1 for C 2H 5HgCl. The same behavior was observed during competitive adsorption in the case of the adsorption from their mixture. The affinity order of mercury species was CH 3HgCl > C 2H 5HgCl > Hg(II). Dithizone-anchored microbeads are suitable for repeated use for more than 5 cycles without noticeable loss of adsorption capacity. Speciation of organomercurials was performed using a Gas chromatography-atomic absorption spectrometry coupled system. Detection limits were increased at least 120-fold with this preconcentration approach using the dithizone-anchored microbeads.

Antimony biomethylation by mixed cultures of micro-organisms under anaerobic conditions

The volatile antimony compound trimethylantimony (TMA) was detected in headspace gases over anaerobic soil enrichment cultures spiked with potassium antimony tartrate. The presence of TMA was variable (12 positives from 104 cultures) and dependent upon both the inoculum source (environmental sample) and enrichment culture conditions. Positives for TMA formation were obtained with variable frequency for four of the six soils tested and for three types of enrichment culture, designed to encourage growth of nitrate-reducing, methane-producing or fermentative bacteria. The identity of the volatile antimony compound produced in each of the three types of enrichment culture was confirmed by gas chromatography-mass spectrometry and gas chromatography-atomic absorption spectroscopy. There was no evidence of any other volatile antimony compound in the headspace gases. These data suggest that the capability to generate TMA is widely distributed in the terrestrial environment and is attributable to different metabolic types of micro-organisms.

Determination of butyltins in harbour sediment and water by aqueous phase ethylation GC-ICP-MS and hydride generation GC-AAS

Sediment and water samples have been collected between 1992 and 1995 for evaluating butyltin contamination in two marinas from the coastal area in The Netherlands, two years after the ban of TBT. Sediments extracts were analysed by capillary gas chromatography-inductively coupled plasma-mass spectrometry. Sediment concentrations for TBT showed no trend of decrease between 1992 and 1995 and were extremely high in the marina secluded from tidal action; 17.5 ± 8.0 μg g −1 and much lower for the marina with tidal action; 0.117 ± 0.073 μg g −1. High ratios between TBT and DBT in the sediments indicate that degradation mechanisms in the sediments are of minor importance. Dissolved butyltin compounds were analysed in water by means of gas chromatography-atomic absorption spectrometry. Water concentrations of TBT showed no clear trend of decrease between 1992 and 1995 and were high in the marina secluded from tidal action; 139 ± 166 ng litre −1 but much lower for the marina with tidal action; 48 ± 98 ng litre −1. An active degradation mechanism during summer periods was indicated by low (<1) TBT/DBT ratios in the water phase of the marina secluded from tidal action.

Occurrence of Butyltin Compounds in Tianjin and Dalian Harbours, China

Abstract Subsurface seawater samples from 12 locations in Tianjin and Dalian harbours were analyzed for butyltin species by gas chromatography-atomic absorption spectrophotometry, and the presence of butyltin species was reported for the first time in these two harbours. Butyltin species were determined in most sampling locations. The concentrations of butyltin species in Tianjin Harbour were higher than those in Dalian Harbour. Some water samples in Tianjin Harbour contained the highly toxic tributyltin at concentrations which could cause growth retardation on chronic exposure to a sensitive organism (rainbow trout yolk sac fry). The concentrations of butyltin species were higher in areas of heavy boating and shipping traffic. This is consistent with butyltin use as an antifouling agent in some paints for boats, ships and docks.

The determination of organotin compounds in edible oils by gas chromatography-atomic absorption spectrometry

An extraction method for butyl-, cyclohexyl-, octyl- and phenyltin compounds from edible oils was developed using 0.05% tropolone in 0.04 M HCl/methanol. Cooling the methanol extracts in a dry ice/methanol bath removed approximately 64% of nonvolatile coextractives without affecting recoveries. Methyl derivatives formed by Grignard reaction were quantitated by gas chromatography-atomic absorption spectrometry. Edible oils sold in poly(vinyl chloride) containers had ng/g levels of dioctyl- and monooctyltin. GCMS confirmed the presence of octyltin and did not detect any other organotin compounds in the extracts.

Determination of butylin compounds in sediment using gas chromatography-atomic absorption spectrometry: comparison of sodium tetrahydroborate and sodium tetraethylborate derivatization methods

Aqueous ethylation and hydride generation, two rapid, convenient speciation techniques used for the determination of bityltin species in river sediments, were compared. After extracting the sediment with methanol containing 0.5 M HCl, the extract was derivatized and analysed by gas chromatography-atomic absorption spectrometry. Monobutyltin and dibutyltin can be determined quantitatively using the hydride generation method; for tributyltin the analysis suffers from critical interference from the sediment extract. With the ethylation method, quantitative determination of dibutyltin and tributyltin in the sediment can be achieved, while a lower recovery of monobutyltin is observed. The detection limits for butyltins in sediments are significantly improved by this method because no foaming occurs during the ethylation step and because the analytical procedure is not hampered by interference from sediment extracts. The detection limits are 0.20, 0.10 and 0.44 ng Sn g −1 dry sediment for mono-, di- and tributyltin, respectively.

Seasonal variation of the ionic alkyllead species composition of rainwater

A comprehensive long-term survey of the concentration levels of ionic alkyllead species in rainwater at a residential location was carried out, relying on a funnel-in-bottle sampler and a well-assessed analytical procedure based on extraction, derivatization, and gas chromatography-atomic absorption spectrometry (GC-AAS). During the 1.5-year monitoring program (1986-1987), the total dissolved ionic alkyllead content of the samples never exceeded 230 ng L -1 Pb and averaged 45 ng L -1 Pb

Determination of Trace Butyltin Compounds in Sea Water by Gas Chromatography-Atomic Absorption Spectrometry

A gas chromatography-atomic absorption spectrometric (GC-AAS) method has been developed for the determination of trace butyltin compounds in sea water. Aqueous butyltin compounds were reduced to the volatile hydride forms by NaBH4 and were extracted with dichloromethane simultaneously. The dichloromethane extract was concentrated under reduced pressure, followed by direct injection into the GC-AAS system for analysis. The butyltin species were separated with a 2-m glass column packed with 2% OV-101 on Chromosorb G HP (100-120 mesh). Following GC separation, each species was transferred into an electrothermally heated (800 °C) quartz furnace for atomization. The tin atoms produced from individual butyltin compound were detected at 224.6 nm by an atomic absorption spectrometer. With a sea water sample (1 L), the detection limits (3σ) for monobutyltin, dibutyltin and tributyltin were approximately 20, 20 and 70 ng Sn L−1, respectively. The method has been applied to the analysis of trace butyltin compounds in the sea water of Keelung Harbor.

Determination of butyltin, cyclohexyltin and phenyltin compounds in beers and wines.

Butyl- cyclohexyl- and phenyltin compounds were extracted from enzymically-hydrolysed wine and beer samples with 0.05% tropolone in pentane. Methyl derivatives were made by Grignard reaction for determination by gas chromatography-atomic absorption spectrometry. Wine and beer samples contained less than 0.1 to 160 nl/ml of butyltins from an undetermined source of contamination. GC-MS confirmation of butyltins also detected phenyltin, and di- and tricyclohexyltin compounds at levels less than the GC-AAS based method detection limits of 0.05-0.13 ng Sn/mL.

Efficiency of tributyltin extraction from rhine river sediment

A Rhine river sediment sample was spiked with tributyltin (TBT), equilibrated for ten days and the tributyltin extraction efficiency was optimised using a simplex algorithm. Analysis was effected using hydride generation gas chromatography-atomic absorption spectroscopy (GC-AAS) apparatus. The results show that, in this sediment sample, different molarities of HCl in methanol extract different species with varying extraction efficiencies. The least polar extraction solution extracted TBT more efficiently, whilst DBT and MBT require molar solution of HCl in methanol for efficient extraction.

Determination of butyltin, methyltin and tetraalkyltin in marine food products with gas chromatography-atomic absorption spectrometry

Extraction methods were developed for the determination of butyltin, methyltin and tetraalkyltin in marine food products. Alkyltins were complexed with either diphenylthiocarbazone (dithizone) or tropolone from enzymatically hydrolysed samples. Tetraalkyltins were extracted with hexane. Butyl or methyl derivatives of the alkyltins were made by Grignard reaction for analysis by gas chromatography—atomic absorption spectrometry. Many of the examined marine food products contained ppb levels of alkyltins. Tetramethyltin and tetraethyltin levels were less than the method detection limits of 0.8 and 0.7 ng/g (as Sn), respectively.

Organic and total lead in selected fresh and canned seafood products

Various fresh and canned seafood products were examined for ionic alkyl lead, tetraalkyl lead and total lead. Dimethyl lead, diethyl lead, trimethyl lead and triethyl lead were extracted with diphenylthiocarbazone (dithizone) at pH 8 and 9 from enzymically hydrolysed samples. Butyl derivatives were formed by Grignard reaction prior to analysis by gas chromatography-atomic absorption spectrometry (GC-AAS). Tetraalkyl lead was extracted from the hydrolysates with hexane. Total lead was determined by reductive coprecipitation with palladium in the presence of ascorbic acid after nitric-perchloric digestion. Many of the samples contained low (less than 0.09-0.7 ng g-1) levels of trimethyl- and dimethyl lead. Triethyl lead was found at similar levels in several samples. Total lead levels were higher with values ranging from less than 5 ng g-1 to 2.9 micrograms g-1. Detection limits for the organolead and total lead methods were 0.07-0.2 and 3-19 ng Pb g-1 respectively.

Speciation of ionic alkyllead in potable water and soil

Various potable water and soil samples have been analyzed for tri- and dialkyllead compounds using a sensitive speciation procedure based on diethyldithiocarbamate extraction, Grignard derivatization and gas chromatography-atomic absorption spectrometry. The species are generally present as ultra-trace contaminants, and their abundance is critically discussed. In addition, a degradation study of ionic alkyllead in ambient matrices is presented.