Dioctyltin and tributyltin detection at trace levels in water and beverages by capillary gas chromatography with flame photometric detection

A simple chromatographic procedure has been developed for the sensitive determination of dioctyltin and tributyltin compounds in water and beverages. Dioctyltin and tributyltin react with NaBH₄ at pH 5 to produce volatile hydrides which can be quantitatively extracted into CH₂Cl₂. The corresponding dioctyltin hydride derivative is identified by HPLC-ES-MS and measured by flame photometric detection using the quartz surface-induced tin emission. Detection limits of less than 0.7 pg of tributyltin and 10 pg of dioctyltin were achieved. Results showed that up to 9.5 ng/mL levels of dioctyltin were present in beverages. Received: 20 July 1998 / Revised: 26 August 1998 / Accepted: 28 August1998     

Trialkyltin Compounds as Neutral Carriers for Anions in PVC Liquid Membranes and Complex Formation with Oxoanions

Under the influence of an electric field, trialkyltin compounds of the type R₃SnX behave as electrically neutral carriers for anions in poly(vinyl chloride) liquid membranes. The interaction of tinorganic compounds with oxoanions was studied in organic phase by means of ¹¹⁹Sn-NMR-monitored titrations. In the case of tributyltin chloride, no appreciable amount of complex was formed with hydrogensulfate, whereas dihydrogenphosphate gave rise to a new species. Dioctyltin dichloride and dioctyltin dioctyltin diacetate formed a 1:2 (salt/ligand) complex with hydrogenphosphate.     

Determination of lanthanum and rare earth elements in bovine whole blood reference material by ICP-MS after coprecipitation preconcentration with heme-iron as coprecipitant

An analytical method for the determination of lanthanide elements in the bovine whole blood reference material (IAEA A-13) has been investigated by inductively coupled plasma mass spectrometry (ICP-MS). The bovine whole blood reference material was digested with HNO₃ and HClO₄, and then the pH of the digested solution was adjusted to 12 with 3 M sodium hydroxide aqueous solution. In this experimental procedure, lanthanide elements in the blood sample were coprecipitated with iron mainly derived from heme-iron in blood itself. In order to minimize matrix effects due to iron, excess iron in the analysis solution was removed by solvent extraction using methyl isobutyl ketone (MIBK) prior to the determination of lanthanide elements by ICP-MS. The recoveries of all lanthanide elements were almost quantitative in the recovery test. In consequence, it has been found that all lanthanide elements in bovine whole blood reference material are at the wide concentration range of 0.90 pg/g for Tm ∼1880 pg/g for Ce. Received: 2 May 1998 / Revised: 27 July 1998 / Accepted: 30 July 1998     

Determination of lanthanum and rare earth elements in bovine whole blood reference material by ICP-MS after coprecipitation preconcentration with heme-iron as coprecipitant

An analytical method for the determination of lanthanide elements in the bovine whole blood reference material (IAEA A-13) has been investigated by inductively coupled plasma mass spectrometry (ICP-MS). The bovine whole blood reference material was digested with HNO₃ and HClO₄, and then the pH of the digested solution was adjusted to 12 with 3 M sodium hydroxide aqueous solution. In this experimental procedure, lanthanide elements in the blood sample were coprecipitated with iron mainly derived from heme-iron in blood itself. In order to minimize matrix effects due to iron, excess iron in the analysis solution was removed by solvent extraction using methyl isobutyl ketone (MIBK) prior to the determination of lanthanide elements by ICP-MS. The recoveries of all lanthanide elements were almost quantitative in the recovery test. In consequence, it has been found that all lanthanide elements in bovine whole blood reference material are at the wide concentration range of 0.90 pg/g for Tm ∼1880 pg/g for Ce. Received: 2 May 1998 / Revised: 27 July 1998 / Accepted: 30 July 1998     

Phase relations in the system V/Nb/O. V. Investigation of mixed crystals V1-xNbxO2

Mixed crystals V_1-xNb_xO₂ exist over the whole area of the quasibinary line VO₂-NbO₂. The existence of Nb_{5+ beside V3+ and V4+ on the V-rich side and V3+ beside Nb5+ and Nb4+ on the Nb-rich side of the mixed crystals is demonstrated by XANES-measurements. The compound VNbO}4_(V0.5_Nb0.5_O2_{) is described as a double oxide with vanadium only as V3+ and niobium only as Nb5+. At this point the electric resistivity of the solid solution shows a maximum.} Received: 11 May 1998 / Revised: 4 August 1998 / Accepted: 10 August 1998     

The nature of corrosion products in lead pipes used to supply drinking water to the City of Glasgow, Scotland, UK

Corrosion products, obtained from lead service pipes carrying the public drinking water supply to the Glasgow area, have been characterised by FTIR spectrometry, powder x-ray diffraction spectrometry, flame atomic absorption spectrometry and ion chromatography. As expected, the products which formed in the presence of pH adjusted-water were mainly lead carbonate or basic lead carbonate. Products from areas where the water supply had been treated with orthophosphoric acid and pH adjustment for up to eight years also contained a variable proportion (up to ∼30% w/w) of a phosphate species. This has been identified as an apatite, most probably lead hydroxyapatite, Pb₅(PO₄)₃OH. Received: 3 August 1998 / Revised: 26 August 1998 / Accepted: 28 August 1998     

Effects of tin(IV) chloride and of organotin compounds on aquatic micro-organisms

The growth response of the alga Chlorella kessleri and the euglenoid Euglena gracilis has been studied as a model system to determine the effects of a tin salt (SnCl₄·5H₂O) and of some organotin (OT) derivatives, namely tetrabutyltin (TeBT), tributyltin (TBT) and tributyltin oxide (TBTO). Abiotic degradation was studied as well. Cells were exposed to a toxicity series (0–50 μg/mL⁻¹) for the four chemicals in seven-day bioassays. Both microorganisms are tolerant of the inorganic salt, but growth inhibition was significant for all OT compounds, and especially large for TBT and TBTO. Although C. kessleri and E. gracilis are known to be tolerant towards metals and organic chemicals, the present results show that both are sensitive to organotin compounds: the inhibition of the growth was greater for C. kessleri. © 1998 John Wiley & Sons, Ltd.     

The catalyzed hydrosilation reaction: substituent effects

Ab initio electronic structure calculations using MP2 wavefunctions have been used to investigate a reaction path for the hydrosilation reaction catalyzed by divalent titanium [modeled by TiH₂, TiCl₂, and Ti(C₅H₅)₂]. Optimized structures and energies are presented. All model reactions predict a barrierless reaction path compared to a barrier of 78 kcal/mol for the uncatalyzed reaction. Received: 11 August 1998 / Accepted: 3 September 1998 / Published online: 23 February 1999     

Determination of cyanides in electroplating solutions as Ni(CN)42– and analysis by capillary electrophoresis

A CE method was developed for the determination of total (free and weakly bound) cyanide in electroplating solutions based on the use of a cationic surfactant (TTAB) and complexation with Ni(II)-NH₃ solutions to Ni(CN)₄ ^2–. Both direct complexation and cyanide distillation combined with complexation were tested. Under optimized conditions, this method is time-saving compared to standard methods. Total cyanide determined by CE had detection limits (with respect to the initial sample concentration) of 0.5 μg/mL for direct complexation and 50 ng/mL for distillation combined with complexation. Total cyanide and cyanide not amenable by chlorination (CNAC) were determined in real samples from spent electroplating baths. Received: 5 February 1998 / Revised: 26 July 1998 / Accepted: 1 August 1998     

Structure-activity relationship of some pentacoordinated Tributyltin(IV) complexes derived from sterically hindered Schiff bases of heterocyclic β-diketones

Some pentacoordinated tributyltin(IV) complexes of sterically hindered Schiff bases of heterocyclic β-diketones having the general formula Bu₃SnL (where LH = RC:NZC:C(OH)N(C₆H₅)N:CCH₃ where R = –CH₃, –C₆H₅, –C₆H₄Cl (p) and Z = –C₆H₄Cl(m), –C₆H₄Cl(p) and –C₆H₄Cl(p)] were screened for their antimicrobial activity against the bacterial strain (Bacillus subtillis) and fungal strains (Candida albicans and Aspergillas niger). These monomeric pentacoordinated tributyltin(IV) complexes possess six membered ring which provide stability to the complexes. These complexes possess Sn←N bond scaffold which impart biological activity in tributyltin(IV) complexes. Antimicrobial bioassay results reveal that these tributyltin(IV) complexes derived from sterically hindered Schiff bases of heterocyclic β-diketones were possess more inhibition potential than their respective parent ligands. These pentacoordinated tributyltin(IV) complexes may used as antibiotic drug in future.     

Simultaneous determination of caffeine, theobromine, and theophylline by high-performance liquid chromatography

This work relates the development of an analytical methodology to simultaneously determine three methylxanthines (caffeine, theobromine, and theophylline) in beverages and urine samples based on reversed-phase high-performance liquid chromatography. Separation is made with a Bondesil C18 column using methanol-water-acetic acid or ethanol-water-acetic acid (20:75:5, v/v/v) as the mobile phase at 0.7 mL/min. Identification is made by absorbance detection at 273 nm. Under optimized conditions, the detection limit of the HPLC method is 0.1 pg/mL for all three methylxanthines. This method is applied to urine and to 25 different beverage samples, which included coffee, tea, chocolate, and coconut water. The concentration ranges determined in the beverages and urine are: < 0.1 pg/mL to 350 microg/mL and 3.21 microg/mL to 71.2 microg/mL for caffeine; < 0.1 pg/mL to 32 microg mL and < 0.1 pg/mL to 13.2 microg/mL for theobromine; < 0.1 pg/mL to 47 microg/mL and < 0.1 pg/mL to 66.3 microg/mL for theophylline. The method proposed in this study is rapid and suitable for the simultaneous quantitation of methylxanthines in beverages and human urine samples and requires no extraction step or derivatization.     

Bis(tributyltin) oxide as a wood preservative: Its chemical nature in timber

Tributyltin compounds have been used for many years as wood preservatives. This study has provided, for the first time, an explanation for the previously reported dealkylation and/or volatilization of the tributyltin species in, and from, timber. Thus ¹¹⁹Sn NMR studies have shown that, on impregnation into timber, bis(tributyltin) oxide, (Bu₃Sn)₂O, is rapidly converted to other tributyltin species, Bu₃SnOX, and that these subsequently undergo disproportionation to Bu₄Sn and Bu₂Sn(OX)₂ compounds. We have additionally demonstrated that Bu₄Sn, so produced, is not persistent in timber and is lost by volatilization. Since the rate of disproportionation of the Bu₃SnOX species should be dependent upon the nature of the X group, it should be possible to affect significantly, if not to stop, this process by the use of alternative tributyltin fungicides, e.g. tributyltin methanesulphonate. However, tributyltin fungicides have been used successfully in wood preservation for at least 25 years. Therefore, it must be concluded that, even after disproportionation in timber, in service, sufficient preservative action is retained to prevent decay of wood under the conditions of natural exposure.     

Simultaneous determination of acetylsalicylic acid and salicylic acid in human plasma by isocratic high‐pressure liquid chromatography with post‐column hydrolysis and fluorescence detection

A selective, sensitive and rapid high‐performance liquid chromatography method with post‐column hydrolysis and fluorescence detection was developed for the simultaneous quantification of acetylsalicylic acid and its metabolite salicylic acid in human plasma. Following the addition of 2‐hydroxy‐3‐methoxybenzoic acid as internal standard and simple protein precipitation with acetonitrile, the analytes were separated on a ProntoSIL 120 C₁₈ ace‐EPS column (150 × 2 mm, 3 µm) protected by a C₈ guard column (5 µm). The mobile phase, 10 mm formic acid in water (pH 2.9) and acetonitrile (70:30, v/v), was used at a flow rate of 0.35 mL/min. After on‐line post‐column hydrolysis of acetylsalicylic acid (ASA) to salicylic acid (SA) by addition of alkaline solution, the analytes were measured at 290 nm (λ_ex) and 400 nm (λ_em). The method was linear in the concentration ranges between 0.05 and 20 ng/μL for both ASA and SA with a lower limit of quantification of 25 pg/μL for SA and 50 pg/μL for ASA. The limit of detection was 15 pg/μL for SA and 32.5 pg/μL for ASA. The analysis of ASA and SA can be carried out within 8 min; therefore this method is suitable for measuring plasma concentrations of salicylates in clinical routine. Copyright © 2012 John Wiley & Sons, Ltd.     

气相色谱—表面发射火焰光度检测法测定环境水样中的二辛基锡

建立了测定环境水样中二辛基锡化合物的气相色谱法。该法用硼氢化钠把二辛基锡氯化物衍生成氢化物，以二氯甲萃取后，用气相色谱－表面发射火焰光度检测器分析测定。     

Synthesis of isotactic,syndiotactic, and heterotactic poly(tributyltin methacrylate) and poly(tributyltin methacrylate-co-styrene)

Pure isotactic and enriched syndiotactic poly(tributyltin methacrylate) were synthesized by the reaction of the respective poly(methacrylic acid) with tributyltin oxide. The heterotactic polymer was prepared in a similar manner and from free radical initiated (AIBN or BPO) polymerization of tributyltin methacrylate. In each case, polymer configuration was confirmed by ¹H-NMR of the hydrolyzed/esterfied product. The relatively large ¹¹⁹Sn-NMR linewidth of the isotactic tributyltin containing polymer suggests an intra-molecular exchange of the pendant tin groups. T_g, T_d, and M _v data are also reported. Poly(tributyltinmethacrylate-co-styrene) was prepared by free radical polymerization and reactivity ratios [r(styrene) = 0.51, r(TBTM) = 0.49] and Q-e values for TBTM (0.78, 0.38) were determined.     

Speciation of butyltins in fish and sediment by means of gas chromatography with flame photometric detection

A modified method for the determination of tributyl-, dibutyl-, and monobutyl-tin in fish and sediment samples is proposed. The samples are digested with hydrochloric acid and the butyltin compounds are extracted into a tropolone solution in pentane and pentylated by a Grignard reaction. The products are cleaned up by washing with a sodium hyrdoxide solution, dried over sodium sulphate, concentrated by evaporation and analysed by gas chromatography with flame photometric detection, using an interence filter at 610 nm. Problems peculiar to the fish and sediment samples are overcome by this improved clean-up procedure. The limit of detection for tributyltin in fish is 0.04 m?g g^?1 and the reproducibility at 0.06 μg g^?1, expressed as the relative standard deviation, is 6.8%. Contaminated sediment samples were found to contain the mixed methylbutyl-tin compounds Me₂BuSn⁺ and MeBu₂Sn⁺.     

Determination of glucose in soft drink and sugar-cane juice employing a multicommutation approach in flow system and enzymatic reaction

A flow system based on a multicommutation approach was developed for the determination of glucose and sucrose employing enzymatic reactions. The determination was based on the reaction with D-glucose generating hydrogen peroxide catalyzed by glucose-oxidase (GOD). Subsequently, the H₂O₂ generated reacts with 4-aminefenazone plus phenol to form 4-(p-benzoquinone-mono-imine) fenazone detected at 510 nm. This reaction is catalyzed by the peroxidase enzyme (POD). The flow network comprised a set of three-way solenoid valves and was controlled by means of a microcomputer furnished with an electronic interface and running a software written in Quick BASIC 4.5. The flow network and control software were designed to implement the multicommutation approach providing facilities to handle sample and reagent solutions, so that, sample dilution could be easily performed on line. Accuracy was assessed by comparison with results obtained by known procedures and no significant difference at the 95% confidence level was observed. Other advantageous features were a linear response ranging from 0.05 to 0.20% (w/v) glucose without prior dilution, a reagent consumption of 336 μL per determination, an analytical throughput of 30 samples per hour. Received: 24 August 1998 / Revised: 13 November 1998 / Accepted: 19 December 1998     

ESR study of NiIII complexes with nitrosonaphthols and dithio acids

Mixed-ligand Ni^III complexes with -nitroso--naphthol, -nitroso--naphthol,o-ethylxanthate, andN,N-diethyldithiocarbamate as ligands have been studied by ESR in liquid and frozen solutions. The degrees of symmetry distortion for the first coordination sphere of these complexes have been determined. It is shown that the transition from planar square Ni^IIL₂ complexes to more stable octahedral Ni^IIIL₂L and Ni^IIILL₂ complexes occursvia the radical addition mechanism. A method for trapping short-lived radicals is suggested on the basis of the complex formation scheme.Translted fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1513–1515, August, 1995.The work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-5050)     

Speciation of organotin in sediments by multicapillary gas chromatography with atomic emission detection after microwave-assisted leaching and solvent extraction-derivatization

Microwave-assisted leaching of organotin compounds from sediment samples followed by the simultaneous extraction-derivatization of the extracted species was revisited with the goal to compare the existing procedures, improve their recoveries and extend them to phenyltin compounds. The stability of butyl- and phenyltin compounds under microwave field, real recoveries of the whole analytical procedure, effect of the extraction solvent, and the necessity for an internal standard were evaluated using two candidate reference sediments. The combination of the optimized sample preparation procedure with multicapillary chromatography resulted in a rapid (2 min leaching + 5 min extraction-derivatization + 3 min chromatographic separation) and efficient analytical procedure for speciation analysis of organotin compounds in sediment samples. The detection limit achieved with a microwave-induced plasma atomic emission detector was 2 ng g^–1. Received: 27 July 1998 / Revised: 31 August 1998 / Accepted: 4 September 1998     

The synthesis,structural characterization and biocidal properties of some triorganotin(IV) esters of N-arylidene-ω-amino acids.

The methods of synthesis, elemental analysis, IR and NMR spectroscopic data and fungicidal activity against Ceratocystis ulmi are reported for a series of triorganotin esters of N-arylidene-ω-amino acids of general formula R₃SnOCO(CH₂)_nN = CHAr (R = Ph, n-Bu; Ar = 2-HOC₆H₄, 2-HOC₁₀H₆; n = 1, 2, 3 and 5). The crystal structures for two of the compounds, tributyltin N-2-hydroxynaphthalidene glycinate ( 1 ) and tributyltin N-2-hydroxynaphthalidene-β-alaninate ( 2 ), have been determined. Although both of these compounds have a trans-R₃SnO₂ structure, in compound 1 the carboxylate group is monodentate and the fifth coordination position around the tin atom is taken up by a coordinated phenolic group, whereas in 2 the carboxylate group is bridging. These two examples thus correspond to the two different structures reported for trans-R₃SnO₂ complexes. Both compounds were found to be active against Ceratocystis ulmi, but there was no significant difference in their levels of biological activity against this particular fungus. Apart from compound 1 , the other tributyltin compounds reported are believed to adopt the carboxylate bridging mode shown by compound ( 2 ). Crystal data: for 1 , crystals monoclinic, space group P 2₁/ c , a = 12.9435(11) Å, b = 13.5769(10) Å, c = 15.7715(12) Å, β = 108.919(6)°, Z = 4, R _f = 0.046 and R _w = 0.058 for 1448 significant reflections; for 2 , crystals monoclinic, space group C 2/ c , a = 24.588(14) Å, b = 9.733(3) Å, c = 27.611(12) Å, β = 113.49(4)°, Z = 8, R _f = 0.053 and R _w = 0.069 for 3822 significant reflections. © 1998 John Wiley & Sons, Ltd.