A simplified procedure for the determination of butyltin species in water

A method is described for the analysis of solutions containing inorganic tin and butyltin compounds. It can be used to determine total tin at a concentration of 20 ng dm^?3 using a 5 dm³ sample. The method is based on solvent extraction with dichloromethane containing tropolone and determination of the tin as inorganic tin by atomic absorption spectroscopy using electrothermal atomization. The extracted butyltin compounds can be separated by paper chromatography and the tin content of the individual spot determined as above. Observations on the stability of butyltin compounds in water at the ～2 mg dm^?3 (Sn) are included.     

Determination of butyltin compounds in sediments using an improved aqueous ethylation method

We have determined tributyltin and dibutyltin species in various environmental sediment samples (marine, harbour and river sediment) using the in situ aqueous ethylation-gas chromatography-atomic absorption spectrometry method subsequent to extraction by methanol containing O.5M HCl. The present technique provides a significantly lower detection limit than previous methods, so that tributyltin can for the first time be measured in some of the samples. Thus, the method described is well suited for the determination of tributyltin and dibutyltin compounds in sediments with low levels of butyltin species (e.g., Main River, 1.7 ng of tributyltin as Sn/g dry sediment).     

Speciation of butyltin compounds in marine sediments by preconcentration on C60 and gas chromatography-mass spectrometry

A new method for the speciation of butyltin compounds by solid phase extraction and direct injection using gas chromatography-mass spectrometry (GC/MS) is described. The compounds were complexed with sodium diethyldithiocarbamate and retained on a C60 sorbent column. The neutral chelates of butyltin compounds were eluted with ethyl acetate containing NaBPr4 as derivatising reagent. The main analytical figures of merit of the proposed method for 10 ml of sample are: linear range 0.2-35 ng/g expressed as Sn; limits of detection, 0.07, 0.09 and 0.10 ng/g as Sn for monobutyltin, dibutyltin and tributyltin, respectively. No interferences from metal ions such as Zn2+, Fe3+, Sb3t, Pb2+, Ni2+ and Mn2+ were observed in the determination of organotin compounds. The validation of method was performed out by the analysis of a standard reference sediment (CRM 462). The method was also applied to the determination of butyltin compounds in marine sediment samples.     

Speciation of butyltin compounds by ion chromatography coupled to electrothermal atomic absorption spectrometry

A new method for the determination of butyltin species by ion-exchange chromatography linked with graphite-furnace electrothermal atomic absorption spectrometry (ETAAS) is presented. The separation is achieved on a strong cation-exchange column with a 0.18 mol dm^?3 solution of diammonium citrate at pH 6.5 with a step change to pH 4.0 in 60:40 methanol/water solvent. ETAAS detection is performed on-line using an oxidizing matrix modifier. Mono-, di- and tri-butyltin may be determined in a single experiment with detection limits of (respectively) 0.5, 1.1 and 0.8 ng (Sn). Applications to actual samples are reported.     

Comprehensive study of the parameters influencing the detection of organotin compounds by a pulsed flame photometric detector in sewage sludge

An investigation of the operating conditions of a pulsed flame photometric detection (PFPD) system for the determination of organotin compounds (OTCs) in sewage sludge is reported. During the analyses, some spectral interferences were observed. For their elimination detector parameters such as gate delay and gate width were investigated. In addition, the applicability of three different internal standards was evaluated. Under optimised analytical conditions (gate delay 3 ms, gate width 2 ms, tripropyltin as internal standard) limits of detection (LOD) were determined. The LOD for butyltins ranged between 8 and 16 ng Sn g(-1), for phenyltins around 8 ng Sn g(-1) and for octyltins between 5 and 10 ng Sn g(-1). Since there is no certified reference material (CRM) available for sewage sludge, the accuracy of the analytical procedure was checked by the analysis of CRM PACS-2 (marine sediment) and a spiked sludge sample. Good agreement between determined and certified values was obtained. Sewage sludge from a local wastewater treatment plant was analysed and the results compared with data from the literature.     

Interpretation of butyltin mass spectra using isotope pattern reconstruction for the accurate measurement of isotope ratios from molecular clusters

The fragmentation patterns of butyltin compounds (mono-, di-, and tributyltin) in an electron impact ion source were studied using an isotope pattern reconstruction algorithm with emphasis on isotope ratio measurements from molecular clusters. For this purpose, standards of natural tin isotope abundance and a (119)Sn-enriched mixture of the three compounds were both ethylated and propylated using sodium tetraalkylborates. The corresponding mass spectra of the various tetraalkyltin compounds prepared were obtained by GC/MS after their extraction with hexane.The results showed that pure interference-free molecular clusters were obtained only for certain R(3)Sn(+) ions where no isobaric overlap with R(2)SnH(+) ions occurred (e.g. BuEt(2)Sn(+) overlaps with Bu(2)SnH(+)). These ions are ideal candidates for accurate Sn isotope ratio measurements, while isotope pattern perturbing interferences are observed for other molecular fragments down to Sn(.)(+). Isotope pattern reconstruction algorithm thus can be used as an analytical tool to ensure the absence of molecular interferences--a requirement for accurate isotope ratio measurements from molecular clusters. The relevance of these studies for the determination of butyltin compounds in environmental samples by isotope dilution GC/MS is also discussed.     

Butyltin compounds in vinegar collected in Beijing: Species distribution and source investigation

Forty-eight vinegar samples including white vinegar,rice vinegar and mature vinegar were collected from several markets in Beijing.Butyltin compounds were determined by headspace solid-phase microextraction coupled with gas chromatography and flame photometric detector after in situ ethylation with sodium tetraethylborate.Butyltin species were detected in sixteen vinegar samples and ranged from 0.012 to 14.10 μg Sn L 1.The detection rate of white vinegar is higher than that of rice vinegar and mature vinegar.Vinegar samples with relatively high butyltin concentration(>1.5 μg Sn L 1) were those stored in plastic bags,indicating that the plastic bag was one of the possible sources of butyltin contamination.This was further confirmed by the leaching experiments of three selected plastic bags,and monobutyltin was detected in the leaching solvents.According to the estimation,the average daily intake of total butyltin compounds through vinegar consumption is about 0.04 ng Sn/kg b.w.,much lower than the Tolerable Daily Intake(TDI) of 100 ng Sn/kg b.w.set by the European Food Safety Authority(EFSA).     

水相中丁基锡化合物同时衍生／萃取气相色谱／火焰光度检测方法研究

本文建立了水相中丁基锡化合物的衍生／萃取一步进行气相色谱／火焰光度检测的方法，探讨了溶剂，氮气流速，温度及火焰条件对分离及测定的影响，获得了理想的分离及检测条件。检出限分别为一丁基锡（ＭＢＴ）及二丁基锡（ＤＢＴ）０．２５ｎｇ，三丁基锡（ＴＢＴ）及四丁基锡（Ｂｕ４Ｓｎ）０．５ｎｇ；线性范围０－８ｎｇ，相对标准偏差小于４％。     

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 compounds in environmental samples by isotope-dilution GC–ICP–MS

Isotope-dilution analysis in combination with GC-ICP-MS detection has been applied to the determination of butyltin species in environmental samples. Different spikes containing the isotopically labeled butyltin species have been synthesized in the laboratory after optimization of the reaction conditions. The isotopic compositions of the tin species in the different spike solutions were determined by GC-ICP-MS after derivatization by aqueous ethylation with sodium tetraethylborate. Reverse isotope-dilution analysis was used for quantitation of the spike solutions by means of natural MBT, DBT, and TBT standards. The mixed spikes were used for simultaneous analysis of MBT, DBT and TBT in the certified reference materials, PACS-2, CRM 462, and CRM 646, with satisfactory results. The excellent agreement of the different speciation results obtained by use of the different spikes is a good indicator of the precision, accuracy, and reliability which can be achieved by using isotope-dilution analysis for trace metal speciation.Application of a double spike containing (119)Sn-enriched MBT (79.7 At%), (118)Sn-enriched DBT (86.7 At%), and (119)Sn-enriched TBT (83.1 At%) also enabled evaluation of the conditions resulting in quantitative extraction of the species from the solid matrix, in combination with possible alterations depending on the different extraction procedures used (mechanical shaking, ultrasounds, and microwaves). Mathematical equations used for this purpose computed the correct species concentrations directly and, additionally, the decomposition factors (from TBT to DBT and from DBT to MBT) after precise measurement of the (119)Sn/(120)Sn and (118)Sn/(120)Sn ratios for all butyltin species by GC-ICP-MS.     

Isotope dilution GC-MS routine method for the determination of butyltin compounds in water

A standard GC-MS instrument with electron impact ionisation has been used to develop a fast, simple and reliable method for the simultaneous determination of monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) in water samples. Isotope dilution analysis (IDA) is used for the determination of species, taking advantage of a commercially available spike solution containing a mixture of MBT, DBT and TBT enriched in ¹¹⁹Sn. Method detection limits for 100-mL samples were between 0.18 and 0.25 ng L⁻¹ for the three butyltin compounds with typical RSD between 2 and 4% at levels between 100 and 10 ng L⁻¹, respectively. Recovery of tin species in spiked samples (natural water, wastewater and seawater) was quantitative. The stability of butyltin compounds in collected seawater samples was also studied. The addition of a 1% (v/v) glacial acetic acid preserved tin species in the samples for at least 5 days at room temperature. The IDA method was finally implemented in a routine testing laboratory and it was subsequently accredited by the Spanish National Accreditation Body according to the requirements of UNE-EN ISO/IEC 17025.     

Determination of perfluorooctanesulfonate and perfluorooctanoic acid in sewage sludge samples using liquid chromatography/quadrupole time-of-flight mass spectrometry

A new method is developed for the determination of perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) in sewage sludge samples. The analytes in sewage sludge samples are extracted by methanol and formic acid, cleaned by C18 solid-phase extraction, then separated, identified and quantitated by liquid chromatography/quadrupole time-of-flight mass spectrometry (LC–QTOF-MS). A C18 column (150 mm × 2.1 mm, 3.5 μm) with gradient elution of MeOH–H₂O (60:40) containing 5 mmol/L ammonium acetate and MeOH–H₂O (80:20) is used for the chromatographic separation. [M−K]⁻ ions at m/z 498.93 for PFOS and [M−COOH]⁻ ion at m/z 368.97 for PFOA are selected for QTOF-MS in the negative electrospray ionization mode. The detection limits for PFOS and PFOA in sewage sludge samples are 0.5 and 0.8 ng/g, respectively. The spiked recoveries are in the range of 85–114 and 71–98% for PFOS and PFOA, respectively. The proposed method is successfully applied to the analysis of PFOS and PFOA in 16 sewage sludge samples from China. PFOS and PFOA are detected in most sewage sludge samples and the concentrations of PFOS and PFOA are up to 5383 and 4780 ng/g (oven dry weight), respectively.     

Occurrence of Volatile Metal and Metalloid Species in Landfill and Sewage Gases

Abstract

Speciation of volatile metals and metalloids in the environment is extensively described in literature. In order to investigate unstable volatile organometallics, on-line coupling of GC with ICP-MS was used. Preliminary results for gases of sewage sludge fermentation at thermophilic and mesophilic conditions are compared with the metal and metalloid speciation in landfill gases. In each case 20 L gas were sampled by cryogenic trapping. The species were identified by element-specific detection either by retention time of standards or by calculation of the boiling point correlation. Characteristic of the separation is the linear correlation of boiling point (bp/°C) versus retention time (rt/min) (bp = 6.39?rt -109.2, r² = 0.9926). The amounts of total volatile elements are estimated by semi-quantification. Cd, Sn. Hg, Pb (sewage gas) and Se, Te, Hg, Pb (landfill gas) were determined in the range of ng m^?3 level; As, Sb, Te and Bi (sewage gas) and As, Sn, Sb and Bi (landfill gas) in the μg m^?3 level range.     

Determination of butyltin species in natural waters using aqueous phase ethylation and off-line room temperature trapping

Monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT) were determined in natural water samples by aqueous phase ethylation with sodium tetraethylborate (STEB), room temperature trapping of the resulting volatile derivatives on Tenax TA^®, followed by gas chromatography-quartz furnace atomic absorption spectrometry (GC-QFAAS). Recoveries of butyltin spikes from natural water samples were 90-109% at concentrations of ∼100 ng Sn/l. The method precision at ∼100 ng Sn/l was ≤6% RSD for butyltins spiked into natural waters. The detection limits for 1 l water samples were <1 ng Sn/l for all butyltin species. Sample throughput of the method is high (greater than three samples per hour) due to the two-stage nature of the procedure, which allows derivatisation/trapping and GC-QFAAS quantitation to be performed separately. Off-line trapping is also advantageous as it extends the life of the GC column and quartz furnace to at least 12 months due to minimisation of carry-over of co-purged material.     

Preparation of a sewage sludge laboratory quality control material for butyltin compounds and their determination by isotope-dilution mass spectrometry

The characterisation of a laboratory quality control material (QCM) for dibutyltin (DBT) and tributyltin (TBT) in sewage sludge is described. The reference values were determined by the use of two different types of isotope-dilution mass spectrometry: gas chromatography–mass spectrometry and gas chromatography–inductively coupled plasma mass spectrometry. To avoid possible analytical errors such as non-quantitative extraction and species degradation during sample preparation, different extraction methods were tested (microwave- and ultrasound-assisted extraction and mechanical stirring). The reference values were based on the unweighted means of results from the homogenisation and characterisation studies. The reference values obtained were 1,553 ± 87 and 534 ± 38 ng Sn g^-1 for DBT and TBT, respectively. In the uncertainty budget estimation, the sample inhomogeneity and between-method imprecision were taken into account. The concentrations of DBT and TBT in QCM are similar to those in the harbour sediment certified reference material PACS-2. Likewise, the levels of DBT and TBT are in the range of these compounds normally present in sewage sludge worldwide. In the future, the QCM will be used for an intercomparison study on DBT and TBT in sewage sludge, and as a day-to-day QCM during studies concerning the application of sewage sludge as an additive to artificial soil or as a raw material in civil engineering construction.     

GC-MS analysis of organic compounds in wastewater and sewage sludge

A multimethod based on liquid-liquid extraction and solid-liquid extraction for the analysis of persistent organic pollutants in water and sludge from sewage treatment plants has been established. Traces of 22 organic compounds used in industry and personal care products (PCPs) were analyzed by GC/MS. The LODs for the analytes were less than 2.3 ng/L for wastewater and 31 microg/kg (dry weight matter) for sewage sludge. Satisfactory recoveries (70-130%) were achieved. The validated method permits the analysis of water and sludge samples at various stages of the treatment from different sewage treatment plants. Thus, the distribution between water and sludge as well as the dissipation of the compounds analyzed were balanced. By this means, the efficiency of different wastewater treatment plants (WWTPs) can be evaluated and measures can be taken to optimize the treatment process at different stages.     

Determination of Chlorophenols in Sewage Sludge and Soil by High-Performance Liquid Chromatography–Tandem Mass Spectrometry with Ultrasonic-Assisted and Solid-Phase Extraction

Chlorophenols are a category of toxic pollutants that are ubiquitously present in the environment. This paper presents a reliable and feasible method for the determination of five chlorophenols in sewage sludge and soil using liquid chromatography–tandem mass spectrometry (LC-MS/MS). The pretreatment involved ultrasonic-assisted extraction and solid-phase extraction purification with hydrophilic–lipophilic balance cartridges. LC-MS/MS equipped with an electrospray ionization source operated in negative mode was used for detection, and multitude reaction monitoring mode was applied for data acquisition. The pretreatment and working conditions of LC-MS/MS were optimized to achieve satisfactory results. The intra-batch accuracies were 100.5–113.4% with relative standard deviations?≤?15.6% for the chlorophenols in sewage sludge and 71.3–102.7% with relative standard deviations?≤?14.0% for those in soil. The inter-batch accuracies were 86.1–100.5% (relative standard deviations?≤?33.6%) for sewage sludge samples and 70.5–112.5% (relative standard deviations?≤?28.2%) for soil samples, respectively. This method has been applied to the determination of chlorophenols in sewage sludge of wastewater treatment plants and soil collected from Guangzhou, China. Parachlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, and pentachlorophenol were detected in some sewage sludge samples, with concentrations from 0.51 to 13.20?ng/g. In addition, parachlorophenol, 2,3,4,6-tetrachlorophenol, and pentachlorophenol were found in all the soil samples with concentrations from 0.33 to 5.21?ng/g. The chromatographic behavior, on-filter adsorption behavior, and the relationship between optimal collision energies and degree of chlorination of the chlorophenols was investigated. This method will be conducive to environmental research focusing on pollution investigation of chlorophenols in the environment.     

Analysis of polybrominated diphenyl ethers in sewage sludge by matrix solid‐phase dispersion and isotope dilution GC–MS

A method for the determination of 14 polybrominated diphenyl ethers (PBDEs) in sludge from wastewater treatment plants is presented. PBDEs were extracted by matrix solid‐phase dispersion assisted by sonication and determined by isotope dilution gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode, using labelled ¹³C‐PBDEs as internal standards. The limits of detection and quantification for the tri‐ to hepta‐BDEs were in the range of 0.05 to 0.5 ng/g dry weight and 0.15 to 1.8 ng/g dry weight, respectively, and 1.6 ng/g dry weight and 5.6 ng/g dry weight for deca‐BDE‐209. The proposed analytical method was applied to determine PBDE levels in sewage sludge samples collected from 19 water treatment plants located in the province of Madrid (Spain). In all of the examined samples, BDE‐100 and BDE‐154 were the main compounds found with a mean concentration of 3.9 and 2.0 ng/g, respectively. PBDEs were detected in all of the samples, and their total concentrations not considering BDE‐209 were between 3.9 and 23.0 ng/g dry weight. The dominant PBDE congener in sewage sludge was BDE‐209, which constituted 38.7 to 97.3% of the total, and showed concentration levels ranging from 8.1 to 717.2 ng/g dry weight.     

Comparison of two extraction methods for the analysis of per- and polyfluorinated chemicals in digested sewage sludge

A rapid and reliable analytical method, based on ion-pair extraction, clean-up on Envicarb cartridge and detection by liquid chromatography–tandem mass spectrometry (LC–MS/MS), was developed for determination of 17 per- and polyfluorinated chemicals (PFCs) in digested sewage sludge. Envicarb cartridge and six labeled internal standards were selected for the elimination/reduction and correction of matrix effects, respectively. As a result, the matrix effect for perfluorooctane sulfonamides (FOSAs) and perfluorocarboxylic acids (PFCAs) with carbon chain length from C6 to C14 was lowered to a range of −14% to +28%. However, the matrix effect for other analytes was still great mainly due to the absence of appropriate internal standard. Mean recoveries of the target analytes based on matrix spikes, at different spike levels (10–300 ng/g), ranged from 70% to 169%. Relative standard deviations (RSDs) were in the range of 2–20% at different spike levels. The limit of quantification (LOQ) ranged between 0.6 and 30 ng/g. The method was successfully applied to several sewage sludge samples from wastewater treatment plants nearby Zürich, Switzerland. In addition, by comparing the accuracy and precision of ion-pair extraction method and methanol extraction method, we further demonstrated that the ion-pair extraction method can be used for the analysis of PFCs in sludge samples. To our knowledge, this is the first study to extract the PFCs in sewage sludge with ion-pair method and to find unsaturated fluorotelomer carboxylic acids (FTUCAs) in sewage sludge.     

Simultaneous determination of butyltin and phenyltin species in sediments using ultrasound-assisted leaching

A fast and simple procedure is presented for the simultaneous leaching of butyl (mono, di and tributyl) and phenyl organotin species from sediment samples. Leached compounds are further ethylated with sodium tetraethylborate in aqueous medium, and analyzed by gas chromatography. After testing the stability of triphenyltin under different extraction conditions, ultrasound-assisted leaching at room temperature in the presence of acetic acid was been proposed as an extraction procedure compatible with the simultaneous determination of phenyl- and butyltin compounds in sediments. Recoveries between 70 and 90% were obtained for phenyl species in spiked samples prepared in the laboratory. Results for butyltin species were validated by use of the reference material PACS-2. Quantification limits, using GC-MIP-AES as measurement technique, were approximately 5-10 ng g(-1). Precision in the consecutive analysis of three sediment samples varied between 3 and 10%.