Large Volume Injection Gas Chromatography Research Articles

Evaluation of α- and β-Endosulfan Residues in Teas and Yerba Mate Infusions by Bar Adsorptive Microextraction and Large Volume Injection-Gas Chromatography Mass Spectrometry

Tea and yerba mate are traditional beverages prepared through the infusion of leaves of Camellia sinensis and Ilex paraguariensis, respectively. During this process, the leaching of pesticides onto the beverage, such as endosulfan, may occur. In this study, a bar adsorptive microextraction (BAµE) method prior to large gas chromatography mass spectrometry analysis was developed to analyze a- and b-endosulfan in teas and yerba mate infusions. Different sorbent coatings for BAµE were compared and the hydrophilic-lipophilic balanced polymer showed the best selectivity for endosulfan isomers. The method was validated providing good recoveries (varying from 80.4 ± 1.8 to 108 ± 4.9%) and linearities (r2 > 0.99), limits of detection from 8.0 to 4.0 µg kg-1 and limits of quantification from 40 to 20 µg kg-1 for a- and b-endosulfan, respectively. The application of the method in the analysis of real samples showed all free of endosulfan at the limit of detection of the analytical method.

In-Vial Extraction Large Volume Gas Chromatography Mass Spectrometry for Analysis of Volatile PFASs on Papers and Textiles.

Volatile per- and polyfluorinated alkyl substances (PFASs) are found in consumer goods that contribute to human exposure to PFASs. Volatile PFAS precursors transform to perfluorinated carboxylates (PFCAs) and sulfonates (PFSAs) in both humans and the environment. Established methods for volatile PFASs in consumer goods exist, but higher sample throughput and greener sample preparation methods are needed to minimize analyte loss, while maintaining sensitivity. New analytical methodology was developed where a 1.5 × 1.5 cm piece of paper or textile is placed into an autosampler vial with solvent and mass-labeled internal standards, sonicated for 30 min, and directly injected without removal of material from the autosampler vial. Large volume injection (20 μL) gas chromatography mass spectrometry was applied for the quantification for 21 individual PFASs from five classes: fluorotelomer alcohols (FTOHs), fluorinated sulfonamides (N-MeFASA, N-EtFASA), and fluorinated sulfonamidoethanols (N-MeFASE, N-EtFASE). Nontargeted analysis revealed additional C2-C7 homologues of N-MeFASE and N-EtFASE, which accounted for 14-18% of the total volatile PFASs on three textiles. Overlooking short-chain (≤C7) N-MeFASE, N-EtFASE, and long-chained (10:2-14:2) FTOHs on older textiles from the 1980s leads to an underestimation of human and environmental exposure to volatile PFAS.

Application of Programmed Temperature Vaporization Large Volume Injection Gas Chromatography (PTV-LVI-GC) to the Analysis of Polycyclic Aromatic Hydrocarbons (PAHs) in Soils

A sensitive, selective and robust method was developed to quantify low levels of polycyclic aromatic hydrocarbons (PAHs) in soils by means of Programmed Temperature Vaporization - Large Volume Injection (PTV-LVI) coupled to gas chromatography with flame ionization detection. Optimal vent pressure and flux at the PTV inlet of the GC system were determined by comparison of peak areas obtained from injection of a standard PAHs mixture at different conditions. Assessment of method performance was carried out with home-made standards prepared by spiking three non-PAH contaminated soils that contained 1.8%, 4.6% and 25% natural organic matter (NOM), with mixtures of six different PAHs at low concentration levels. Detection limits between 9 and 12 ng g-1 and variation coefficients below 11% were determined from analysis of spiked samples of the soil with lowest NOM content. PAHs recoveries typically ranged from 61% to 96% for the three studied soils.

Dispersive liquid-liquid microextraction for the determination of nitrophenols in soils by microvial insert large volume injection-gas chromatography–mass spectrometry

A rapid and sensitive procedure for the determination of six NPs in soils by gas chromatography and mass spectrometry (GC–MS) is proposed. Ultrasound assisted extraction (UAE) is used for NP extraction from soil matrices to an organic solvent, while the environmentally friendly technique dispersive liquid-liquid microextraction (DLLME) is used for the preconcentration of the resulting UAE extracts. NPs were derivatized by applying an “in-situ” acetylation procedure, before being injected into the GC–MS system using microvial insert large volume injection (LVI). Several parameters affecting UAE, DLLME, derivatization and injection steps were investigated. The optimized procedure provided recoveries of 86–111% from spiked samples. Precision values of the procedure (expressed as relative standard deviation, RSD) lower than 12%, and limits of quantification ranging from 1.3 to 2.6ngg−1, depending on the compound, were obtained. Twenty soil samples, obtained from military, industrial and agricultural areas, were analyzed by the proposed method. Two of the analytes were quantified in two of the samples obtained from industrial areas, at concentrations in the 4.8–9.6ngg−1 range.

Determination of Trace Levels of Irgarol in Estuarine Water Matrices by Bar Adsorptive Microextraction.

Bar adsorptive microextraction (BAµE), using selective sorbent phases, followed by liquid desorption in combination with large volume injection-gas chromatography coupled to mass spectrometry (BAµE-LD/LVI-GC-MS), is proposed for the determination of trace levels of irgarol in estuarine water matrices. While we compared several polymers and activated carbons, one of the latter coatings showed much higher selectivity through BAµE. Assays performed on 25 mL of ultra-pure water sample fortified at 0.6 µg/L levels of irgarol yielded recoveries of 74.5 ± 8.6%, under optimized experimental conditions. The proposed analytical procedure showed convenient detection limits (16.0 ng/L) and good linear dynamic range (0.2-16.0 µg/L), with determination coefficients of 0.9982. Good precision was also achieved with RSD lower than 12.0%. The application of the present analytical approach on estuarine water samples by using the standard addition methodology revealed good sensitivity and linearity. The proposed methodology, using nanostructured sorbents and operating under the floating sampling technology, proved to be a suitable analytical alternative to monitor irgarol in estuarine water matrices. Moreover, it is easy to implement, reliable, sensitive, require low sample volume and have the possibility to choose the most selective sorbent coating according to the target compound involved.

Influence of the drying step within disk-based solid-phase extraction both on the recovery and the limit of quantification of organochlorine pesticides in surface waters including suspended particulate matter

In this study, 21 organochlorine pesticides (OCPs) were determined based on sample preparation using solid-phase extraction disks (SPE disks) coupled with programmable temperature vaporizer (PTV)—large-volume injection gas–chromatography mass spectrometry (LVI-GC–MS). The work includes a comprehensive testing scheme on the suitability of the method for routine analysis of surface and drinking water including suspended particulate matter (SPM) with regard to requirements derived from the European Water Framework Directive (WFD, Directive 2000/60/EC). SPM is an important reservoir for OCPs, which contributes to the transport of these compounds in the aquatic environment. To achieve the detection limits required by the WFD, a high pre-concentration factor during sample preparation is necessary, which was achieved by disk SPE in this study. The performance of disk SPE is strongly influenced by the drying step, which could be significantly improved by effective elimination of the residual water by combination of a high vacuum pump and a low humidity atmosphere. Detection limits of the WFD in the ng/L range were achieved by large volume injection of 100μL sample extract. The recoveries ranged from 82% to 117% with an RSD smaller than 13%. The applicability of this method to natural samples was tested for instrumental qualification and system suitability evaluation. Successful participation in an interlaboratory comparison proved the suitability of the method for routine analysis.

Cyclic volatile methylsiloxanes in human blood as markers for ruptured silicone gel-filled breast implants.

The replacement of medical-grade silicone with industrial-grade silicone material in some silicone gel-filled breast implants (SBI) manufactured by Poly Implant Prothèse and Rofil Medical Nederland B.V., reported in 2010, which resulted in a higher rupture tendency of these SBI, demonstrates the need for non-invasive, sensitive monitoring and screening methods. Therefore a sensitive method based on large volume injection-gas chromatography coupled to mass spectrometry (LVI-GC/MS) was developed to determine octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclo-hexasiloxane (D6) in blood samples from women with intact (n = 13) and ruptured SBI (n = 11). With dichloromethane extraction, sample cooling during preparation, and analysis extraction efficiencies up to 100 % and limits of detection of 0.03-0.05 ng D4-D6/g blood were achieved. Blood samples from women with SBI were investigated. In contrast to women with intact SBI, in blood from women with ruptured SBI higher D4 and D6 concentrations up to 0.57 ng D4/g blood and 0.16 ng D6/g blood were detected. With concentrations above 0.18 D4 ng/blood and 0.10 ng D6/g blood as significant criteria for ruptured SBI, this developed analytical preoperative diagnostic method shows a significant increase of the recognition rate. Finally a higher precision (error rate 17%) than the commonly used clinical diagnostic method, mamma sonography (error rate 46%), was achieved.

Determination of synthetic phenolic antioxidants in edible oils using microvial insert large volume injection gas-chromatography

Three synthetic phenolic antioxidants, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ), were determined in different edible vegetable oil samples. The analyses were carried out by gas chromatography–mass spectrometry (GC–MS) using microvial insert large volume injection (LVI). Several parameters affecting this sample introduction step, such as temperatures, times and gas flows, were optimised. Quantification was carried out by the matrix-matched calibration method using carvacrol as internal standard, providing quantification limits between 0.08 and 0.10ngg–1, depending on the compound. The three phenolic compounds were detected in several of the samples, BHT being the most frequently found. Recovery assays for oil samples spiked at two concentration levels, 2.5 and 10ngg–1, provided recoveries in the 86–115% range.

Analysis of polycyclic aromatic hydrocarbons in aqueous samples by large volume injection gas chromatography–mass spectrometry using the through oven transfer adsorption desorption interface

A new procedure for the determination of 17 polycyclic aromatic hydrocarbons (PAHs) in aqueous samples by large volume injection–gas chromatography–mass spectrometry (LVI–GC–MS) using the Through Oven Transfer Adsorption Desorption (TOTAD) interface with nitrogen for solvent elimination is developed and validated. Up to 75mL of aqueous samples were injected to be sure that good solvent elimination were achieved, although 500µL were sufficient to achieve the required sensitivity.The performance of the developed method can be considered good: the relative standard deviation (RSD), (n=3) was lower than 13.8% for all the target analytes, the concentration of each PAH being 0.25μgL−1, the limit of detection and limit of quantitation ranged from 21.5 to 211.0 ng L−1 and from 71.7 to 703.3ngL−1 respectively, and the correlation coefficients (R2) were all higher than 0.9764 in the 1–16μgL−1 range.

Application of Bar Adsorptive Microextraction-Large-Volume Injection-Gas Chromatography-Mass Spectrometric Method for the Determination of Trace Levels of Agrochemicals in Real Matrices

Bar adsorptive microextraction followed by liquid desorption in combination with large volume injection gas chromatography coupled to mass spectrometry, under selected ion monitoring mode acquisition (BAµE-LD/LVI-GC-MS(SIM)), was applied for the determination of trace levels of different classes of agrochemicals (using alachlor, diniconazole, fenpropathrin, as well as cis and trans-permethrin as model compounds) in environmental water and wine matrices. Assays performed on 25 mL of ultra-pure water samples spiked at the 2.0 µg L-1 level, yielded recoveries ranging from 55.2 to 105.6%, under optimized experimental conditions. The analytical performance showed convenient detection limits (8.0 to 32.0 ng L-1) and good linear dynamic ranges (0.03 to 4.00 µg L-1), with remarkable determination coefficients (r2 > 0.9982). Excellent repeatability, based in relative standard deviation (RSD) was also achieved through intraday (RSD < 7.5%) and interday (RSD < 7.0%) assays. Studies performed on surface and ground water, as well as wine samples, using the standard addition method, revealed good sensitivity at the trace level.

Determination of organochlorines, polychlorinated biphenyls and polybrominated diphenyl ethers in human hair: Estimation of external and internal exposure

A novel method was developed for the analysis of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in human hair samples. External contaminants of hair were extracted with acetone under sonication, while washed hair was further hydrolyzed in formic acid and acetone (1:4, v/v) with microwave assisted extraction (MAE) for internal contaminant measurements. Both internal and external extracts were cleaned up with gel permeation chromatography (GPC) and then solid phase extraction (SPE), before analyzed by a large volume injection-gas chromatography–tandem mass spectrometry (LVI–GC–MS/MS) using triple quadruple mass analyzer. Good linearity (R2⩾0.996) was established within a concentration range between 0.1 and 100ngmL−1 among all target analytes. The method was validated for accuracy, precision and sensitivity. The developed method is intended to be cost effective and robust for the routine human hair analysis of PCBs, PBDEs and OCPs including acid-labile OCPs. The described method has been applied in pilot biomonitoring study and the preliminary data suggested that the contaminant profiles with the use of partial least-squares analysis discriminant analysis (PLA-DA) could be useful in differentiating external and internal exposure.

Determination of tributyltin in environmental water matrices using stir bar sorptive extraction with in-situ derivatisation and large volume injection-gas chromatography–mass spectrometry

Stir bar sorptive extraction with in-situ derivatization using sodium tetrahydridoborate (NaBH4) followed by liquid desorption and large volume injection-gas chromatography–mass spectrometry detection under the selected ion monitoring mode (SBSE(NaBH4)in-situ–LD/LVI-GC–MS(SIM)) was successfully developed for the determination of tributyltin (TBT) in environmental water matrices. NaBH4 proved to be an effective and easy in-situ speciation agent for TBT in aqueous media, allowing the formation of adducts with enough stability and suitable polarity for SBSE analysis. Assays performed on water samples spiked at the 10.0μg/L, yielded convenient recoveries (68.2±3.0%), showed good accuracy, suitable precision (RSD<9.0%), low detection limits (23ng/L) and excellent linear dynamic range (r2=0.9999) from 0.1 to 170.0µg/L, under optimized experimental conditions. By using the standard addition method, the application of the present methodology to real surface water samples allowed very good performance at the trace level. The proposed methodology proved to be a feasible alternative for routine quality control analysis, easy to implement, reliable and sensitive to monitor TBT in environmental water matrices.

Determination of polybrominated diphenyl ethers and polychlorinated biphenyls in fishery and aquaculture products using sequential solid phase extraction and large volume injection gas chromatography/tandem mass spectrometry

A new method was developed to determine polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in fishery and aquaculture products. Samples were extracted by an accelerated solvent extraction system and cleaned up by sequential solid phase extraction (SPE) including dispersive SPE (D-SPE) and tandem SPE. PBDEs and PCBs were analyzed by a large-volume injection gas chromatography triple quadrupole mass spectrometry (LVI-GC-QqQ-MS/MS). Good linearity (R(2)≥0.9958) was achieved. Method detection limits (MDLs) were 0.16-3.3pgg(-1) (wet weight, ww) for PBDEs and 0.13-0.97pgg(-1)ww for PCBs. Mean recoveries were 60-140% with relative standard deviations (RSDs) of less than 20% in weever fish, scallop and shrimp samples spiked at a lower level of 13-31pgg(-1)ww and a higher level of 50-125pgg(-1)ww. Certified reference materials were analyzed with acceptable results. The method reduced solvent consumption, analytical time and labor, and is suitable for the routine analysis of PBDEs and PCBs in fishery and aquaculture products.

Linear and cyclic methylsiloxanes in air by concurrent solvent recondensation–large volume injection–gas chromatography–mass spectrometry

In the present work, a simple and fast method for the analysis of linear and cyclic methylsiloxanes in ambient air based on active sampling combined with gas chromatography - mass spectrometry (GC-MS) was developed. The retention efficiency of five sampling sorbents (activated coconut charcoal, Carbopack B, Cromosorb 102, Cromosorb 106 and Isolute ENV+) was evaluated and Isolute ENV+ was found to be the most effective. A volume of 2700 L of air can be sampled without significant losses of the most volatile methylsiloxanes. To improve the sensitivity of the GC-MS method, concurrent solvent recondensation - large volume injection (CSR-LVI), using volumes up to 30 µl of sample extract, is proposed and limits of quantification down to 0.03-0.45 ng m(-3), good linearity (r>0.999) and precision (RSD %<9%) were obtained. The developed method was applied to the analysis of ambient air. Concentrations of linear and cyclic methylsiloxanes in indoor air ranging from 3.9 to 319 ng m(-3) and between 48 and 292668 ng m(-3), were obtained, respectively, while levels from 6 to 22 ng m(-3) for linear and between 2.2 and 439 ng m(-3) for cyclic methylsiloxanes in outdoor air from Barcelona (Spain), were found.

Separation of polychlorinated dibenzo-p-dioxins/furans, non-ortho/mono/di/tri/tetra-ortho-polychlorinated biphenyls, and polybrominated diphenyl ethers groups of compounds prior to their determination with large volume injection gas chromatography—Quadrupole ion storage tandem mass spectrometry

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are important environmental contaminants. Their maximum legally allowable levels in food and environment are in the low pgg−1 range. Therefore some highly selective and sensitive analytical methods must be used to determine them. Prior to final determination by GC/MS the cleaned-up samples have to be split into some fractions in view of large differences in concentrations of various analytes and existence of numerous chromatographic co-elutions (which in any case cannot be fully avoided). The aim of this study was to: (i) develop a robust, time-saving analytical method to isolate, clean-up and fractionate PCBs, PBDEs and PCDD/Fs prior to their determination with gas chromatography/ion trap mass spectrometry; (ii) assess method performance using laboratory validation data and some certified reference materials; (iii) use the developed method to assess PCB/PBDE/PCDD/F levels in samples of commercially available food. A combination of alumina, florisil, modified silica gel and two carbon columns were used for sample cleanup and fractionation. Separate fractions containing dioxins/furans, PBDE, non-ortho, mono-ortho and di-/tri-/tetra-ortho PCBs were obtained. The method statistical parameters were compatible with 1883/2006 EC Regulation (80–120%, RSD below 15%). The method performance was successfully used to evaluation of some real life food samples.

Development of ultrasound-assisted dispersive liquid–liquid microextraction–large volume injection–gas chromatography–tandem mass spectrometry method for determination of pyrethroid metabolites in brain of cypermethrin-treated rats

3-Phenoxybenzoic acid (3-PBA) and 4-hydroxy-3-phenoxybenzoic acid (OH-PBA) are the two common metabolites for most pyrethroid insecticides. A rapid, sensitive, and eco-friendly method has been developed based on ultrasound-assisted dispersive liquid–liquid microextraction (DLLME) coupled to large volume injection–gas chromatography–tandem mass spectrometry for the simultaneous determination of pyrethroid metabolites in rat brain treated with cypermethrin (CYP). Brain samples were homogenized in methanol (disperser solvent) followed by derivatization with methyl chloroformate (MCF) and extraction using DLLME. Factors that influence the extraction and derivatization efficiency such as type and volume of extraction and disperser solvent, sonication time, pH, ionic strength, and volumes of MCF and pyridine were optimized. Under optimized conditions, the limits of detection were 1 and 4 ng/g for 3-PBA and OH-PBA, respectively. Mean recoveries of pyrethroid metabolites in rat brain were in the range of 83–95 %. The developed method was successfully applied for determination of 3-PBA and OH-PBA in brain samples of CYP-treated rats. The developed method can be adopted for rapid and sensitive analysis of pyrethroid metabolites in toxicological and forensic laboratories.

Determination of polycyclic and nitro musks in environmental water samples by means of microextraction by packed sorbents coupled to large volume injection-gas chromatography–mass spectrometry analysis

In this work the development and validation of a new procedure for the simultaneous determination of 9 nitro and polycyclic musk compounds: musk ambrette (MA), musk ketone (MK), musk mosken (MM), celestolide (ADBI), phantolide (AHMI), tonalide (AHTN), traseolide (ATII), cashmeran (DPMI) and galaxolide (HHCB) in environmental water samples (estuarine and wastewater) using microextraction by packed sorbent (MEPS) followed by large volume injection-gas chromatography–mass spectrometry (LVI-GC–MS) was carried out. Apart from the optimization of the different variables affecting MEPS (i.e., nature of the sorbent, nature of the solvent elution, sample load, and elution/injection volume) extraction recovery was also evaluated, not only for water samples but also for environmental water matrices such as estuarine and waste water. The use of two deuterated analogs ([2H3]-AHTN and [2H15]-MX) was successfully evaluated in order to correct matrix effect in complex environmental matrices such as influent samples from wastewater treatment plants. Method detection limits (MDLs) ranged from 5 to 25ngL−1, 7 to 39ngL−1 and 8 to 84ngL−1 for influent, effluent and estuarine samples, respectively. Apparent recoveries were higher than 75% for all target compounds in all the matrices studied (estuarine water and wastewater) and the precision of the method, calculated as relative standard deviation (RSD), was below 13.2% at 200ngL−1 concentration level and below 14.9% at low level (20ngL−1 for all the target analytes, except for AHTN which was set at 40ngL−1 and HHCB at 90ngL−1, due to the higher MDL values presented by those target compounds). Finally, this MEPS procedure was applied to the determination of the target analytes in water samples, including estuarine and wastewater, from two estuaries, Urdaibai (Spain) and Adour (France) and an established stir-bar sorptive extraction-liquid desorption/large volume injection-gas chromatography–mass spectrometry (SBSE-LD/LVI-GC–MS) method was performed in parallel for comparison. Results were in good agreement for all the analytes determined, except for DPMI.

Determination of cyclic volatile methylsiloxanes in water, sediment, soil, biota, and biosolid using large-volume injection–gas chromatography–mass spectrometry

Several methods were developed to detect the cyclic volatile methylsiloxanes (cVMSs) including octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in water, sediment, soil, biota, and biosolid samples. Analytical techniques employed to optimize measurement of this compound class in various matrices included membrane-assisted solvent extraction in water, liquid–solid extraction for sediment, soil, biota, and biosolid samples. A subsequent analysis of the extract was conducted by large-volume injection–gas chromatography−mass spectrometry (LVI−GC−MS). These methods employed no evaporative techniques to avoid potential losses and contamination of the volatile siloxanes. To compensate for the inability to improve detection limits by concentrating final sample extract volumes we used a LVI–GC–MS. Contamination during analysis was minimized by using a septumless GC configuration to avoid cVMS’s associated with septum bleed. These methods performed well achieving good linearity, low limits of detection, good precision, recovery, and a wide dynamic range. In addition, stability of cVMS in water and sediment was assessed under various storage conditions. D4 and D5 in Type-I (Milli-Q) water stored at 4°C were stable within 29d; however, significant depletion of D6 (60–70%) occurred only after 3d. Whereas cVMS in sewage influent and effluent were stable at 4°C within 21d. cVMS in sediment sealed in amber glass jars at −20°C and in pentane extracts in vials at −15°C were stable during 1month under both storage conditions.

Concentrations of cyclic volatile methylsiloxanes in biosolid amended soil, influent, effluent, receiving water, and sediment of wastewater treatment plants in Canada

A comprehensive surveillance program was conducted to determine the occurrence of three cyclic volatile methylsiloxanes (cVMS) octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in environmental compartments impacted by wastewater effluent discharges. Eleven wastewater treatment plants (WWTPs), representative of those found in Southern Ontario and Southern Quebec, Canada, were investigated to determine levels of cVMS in their influents and effluents. In addition, receiving water and sediment impacted by WWTP effluents, and biosolid-amended soil from agricultural fields were also analyzed for a preliminary evaluation of the environmental exposure of cVMS in media impacted by wastewater effluent and solids. A newly-developed large volume injection (septumless head adapter and cooled injection system) gas chromatography – mass spectrometry method was used to avoid contamination originating from instrumental analysis. Concentrations of D4, D5, and D6 in influents to the 11 WWTPs were in the range 0.282–6.69μgL−1, 7.75–135μgL−1, and 1.53–26.9μgL−1, respectively. In general, wastewater treatment showed cVMS removal rates of greater than 92%, regardless of treatment type. The D4, D5, and D6 concentration ranges in effluent were <0.009–0.045μgL−1, <0.027–1.56μgL−1, and <0.022–0.093μgL−1, respectively. The concentrations in receiving water influenced by effluent, were lower compared to those in effluent in most cases, with the ranges <0.009–0.023μgL−1, <0.027–1.48μgL−1, and <0.022–0.151μgL−1 for D4, D5, and D6, respectively. Sediment concentrations ranged from <0.003–0.049μgg−1dw, 0.011–5.84μgg−1dw, and 0.004–0.371μgg−1dw for D4, D5, and D6, respectively. The concentrations in biosolid-amended soil, having values of <0.008–0.017μgg−1dw, <0.007–0.221μgg−1dw, and <0.009–0.711μgg−1dw for D4, D5, and D6, respectively, were lower than those in sediment impacted by wastewater effluent in most cases. In comparison with the no-observed-effected concentrations (NOEC) and IC50 (concentration that causes 50% inhibition of the response) values, the potential risks to aquatic, sediment-dwelling, and terrestrial organisms from these reported concentrations are low.

Fully automated determination of macrocyclic musk fragrances in wastewater by microextraction by packed sorbents and large volume injection gas chromatography–mass spectrometry

A fully automated method has been developed for the determination of eight macrocyclic musk fragrances in urban wastewater. The procedure includes the enrichment of the analytes by microextraction by packed sorbent (MEPS) followed by large volume injection–gas chromatography–mass spectrometry (LVI–GC–MS). The main factors in the MEPS technique were optimized. For all of the analytes, the highest enrichment factors were achieved when 4mL samples were extracted by using C18 MEPS-sorbent and 50μL of ethyl acetate were used for desorption. The eluate was directly analysed by GC–MS. Detection limits were found to be between 5ngL−1 and 10ngL−1, depending on the target analytes. In addition, under optimized conditions, the method gave good levels of intra-day and inter-day repeatability in wastewater samples with relative standard deviation (RSD) (n=3, 1000ngL−1) less than 5% and 9%, respectively. The applicability of the method was tested with wastewater samples from two influent and effluent urban wastewater treatment plants (WWTPs). The analysis of influent urban wastewater revealed the presence of most of the macrocylic musks at concentrations higher than the method quantification limits (MQLs), being the most abundant analyte ambrettolide at 9.29μgL−1. In addition, the analyses of effluent urban wastewater showed a decrease in the concentrations with macrocyclic musk concentrations of between not detected (n.d.) and 2.26μgL−1 being detected.