Gas chromatography triple quadrupole mass spectrometry method for monitoring multiclass organic pollutants in Spanish sewage treatment plants effluents

Temporal dynamics and ecotoxicological risk assessment of personal care products, phthalate ester plasticizers, and organophosphorus flame retardants in water from Lake Victoria, Uganda

For the first time the occurrence of 25 organic micropollutants (OMPs) including; 11 personal care products (PCPs), six phthalate ester plasticizers (PEPs) and eight organophosphorus flame retardants (OPFRs) was investigated in 72 water samples obtained from five bays in the Uganda sector of Lake Victoria. In addition, an assessment of the potential ecotoxic risk of the target OMPs to aquatic organisms was conducted. Water samples were analyzed for the target OMPs using gas chromatography coupled with mass spectrometry (GC/MS). All the target PCPs were found in all the water samples with the exception of musk ketone and 2,6-di-tert-butylphenol. Triclosan (89-1400 ng L^-1), benzophenone (36-1300 ng L^-1), and 4-methylbenzylidine camphor (21-1500 ng L^-1) were the most predominant PCPs. All the six plasticizers were found in all the water samples with dibutyl phthalate (350-16 000 ng L^-1), and bis-(2-ethylhexyl) phthalate (210-23 000 ng L^-1) detected at the highest concentrations. Five OPFRs out of the eight targeted were found in all the water samples. Tricresyl phosphate (25-8100 ng L^-1), tris-(2-chloroethyl) phosphate (24-6500 ng L^-1) and triphenyl phosphate (54-4300 ng L^-1) were the most dominant OPFRs. The highest concentrations of OMPs were recorded in Murchison and Thurston Bays, presumably due to industrial wastewater effluents from the highly industrialized localities of the two Bays. Ecotoxicological risk assessment showed that PCPs (triclosan, musk ketone, and 4-MBC), plasticizers (dibutyl phthalate, bis-(2-ethylhexyl) adipate and bis-(2-ethylhexyl) phthalate) and OPFRs (tricresyl phosphate, triphenyl phosphate and tris-(2-chloroethyl) phosphate) pose a high ecotoxic risk to lives of aquatic organisms (risk quotients, RQ > 1).

[Research progress on analytical methods for the determination of hexachlorobutadiene]

Hexachlorobutadiene (HCBD) is one of persistent organic pollutants (POPs) listed in Annex A and Annex C of the Stockholm Convention in 2015 and 2017, respectively. Research on the sources, environmental occurrences, and biological effects of HCBD has a great significance in controlling this newly added POPs. Sensitive and credible methods for the determination of HCBD are preconditions and form the basis for related research work. In recent years, many researchers have included HCBD as one of the analytes in monitoring or methodological studies. Based on the results of these studies, this paper reviews the research progress on analytical methods for the determination of HCBD and focuses on sample pretreatment methods for the analysis of HCBD in various matrices such as air, water, soil, sewage sludge, and biological tissues. The advantages and disadvantages of the methods are also compared to provide reference for further research in this field.For air samples, HCBD was usually collected by passing air through sorbent cartridges. Materials such as Tenax-TA, Carbosieve, Carbopack, Carboxen 1000, or their mixtures were used as the sorbent. HCBD was thermally desorbed and re-concentrated in a trap and finally transferred for instrumental analysis. Limits of detection (LODs) for HCBD in these methods were at the ng/m3 scale. Compared to sampling using pumps, passive air samplers (PAS) such as polyurethane foam PAS (PUF-PAS) do not require external power supply and are more convenient for sampling POPs in air at a large scale. The LOD of the sorbent-impregnated PUF PAS (SIP-PAS) method was much lower (0.03 pg/m3) than that of the PUF-PAS method (20 pg/m3). However, the sampling volumes in the SIP-PAS and PUF-PAS methods (-6 m3) calculated from the log KOA value of HCBD have significant uncertainty, and this must be confirmed in the future.For water samples, HCl or copper sulfate was added to the sample immediately after sampling to prevent any biological activities. HCBD can be extracted from water using methods such as the purge and trap method, liquid-liquid extraction (LLE) method, and solid phase extraction (SPE) method. Among these methods, SPE enabled the simultaneous extraction, purification, and concentration of trace HCBD in a single step. Recoveries of HCBD on Strata-X and Envi-Carb SPE cartridges (63%-64%) were higher than those on Envi-disk, Oasis HLB, and Strata-C18 cartridges (31%-46%). Drying is another key step for obtaining high recoveries of HCBD. Disk SPE involving the combination of a high-vacuum pump and a low-humidity atmosphere is an effective way to eliminate the residual water. In addition, a micro SPE method using functionalized polysulfone membranes as sorbents and employing ultrasonic desorption was developed for extracting HCBD from drinking water. The recovery of HCBD reached 102%, with a relative standard deviation (RSD) of 3.5%.For solid samples such as dust, soil, sediment, sewage sludge, fly ash, and biota tissue, multiple pretreatment methods were used in combination, owing to the more complex matrix. Freeze or air drying, grinding, and sieving of samples were commonly carried out before the extraction. Soxhlet extraction is a typical extraction method for HCBD; however, it requires many organic reagents and is time consuming. The accelerated solvent extraction (ASE) method requires a small amount of organic reagent, and the extraction can be performed rapidly. It was recently applied for the extraction of HCBD from solid samples under 10.34 MPa and at 100 ℃. Purification could be achieved simultaneously by mixing florisil materials with samples in the ASE pool. Nevertheless, employing the ASE methods widely is difficult because of their high costs. Ultrasonic-assisted extraction (UAE) has the same extraction efficiency for HCBD, with much lower costs compared to ASE, and is therefore adopted by most researchers. The type of extraction solvent, solid-to-liquid ratio, ultrasonic temperature, and power affect the extraction efficiency. Ultrasonic extraction at 30 ℃ and 200 W using 30 mL dichloromethane as the extraction solvent resulted in acceptable recoveries (64.0%-69.4%) of HCBD in 2 g fly ash. After extraction, a clean-up step is necessary for the extracts of solid samples. Column chromatography is frequently used for purification. The combined use of several columns or a multilayer column filled with florisil, silica gel, acid silica gel, or alumina can improve the elimination efficiency of interfering substances.Instrumental analysis for HCBD is mainly performed with a gas chromatograph equipped with a mass spectrometer operating in selected ion monitoring mode. DB-5MS, HP-5MS, HP-1, ZB-5MS, and BP-5 can be used as the chromatographic columns. Qualification ions and quantification ions include m/z 225, 223, 260, 227, 190, and 188. GC-MS using an electron ionization (EI) source was more sensitive to HCBD than GC-MS using a positive chemical ionization source (PCI) and atmospheric pressure chemical ionization source (APCI). Gas chromatography-tandem mass spectrometry (GC-MS/MS), gas chromatography-high-resolution mass spectrometry (GC-HRMS), and high-resolution gas chromatography-high-resolution mass spectrometry (HRGC-HRMS) have recently been used for the separation and determination of HCBD and various other organic pollutants. Instrumental detection limits for HCBD in GC-MS/MS, GC-HRMS, and HRGC-HRMS were more than ten times lower than that in GC-MS, indicating the remarkable application potential of these high-performance instruments in HCBD analysis.

Screening and quantification of emerging contaminants in Periyar River, Kerala (India) by using high-resolution mass spectrometry (LC-Q-ToF-MS)

The presence of emerging contaminants (ECs) in different aquatic systems may contribute to hazardous effects on aquatic organisms and subsequently on human health. In the present work, liquid chromatography coupled to a quadrupole time of flight mass spectrometer (LC-Q-ToF-MS) was used to identify and quantify a series of ECs in Periyar River in Aluva region, Kerala, India. The water samples were pre concentrated using solid-phase extraction (SPE) prior to analysis. The compounds were probed in both positive and negative ionization mode using electro spray ionization (ESI). Method validations were performed for linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision (intraday and inter day). The ECs were quantified using standard calibration curve. The identified nine ECs include pharmaceuticals, personal care products, steroids, surfactants, and phthalate. A relatively high concentration was observed in the case of 2-dodecyl benzene sulfonic acid (1012 ng/l) and low concentration was observed for lignocaine (4.3 ng/l; since this is below LOQ, the value is only approximate). In addition, we have identified another 28 organic compounds using the technique of non-target analysis out of which seven compounds fall in the category of surfactants. Being the first report on ECs in Periyar River, the data is very important as this river is one of the biggest and important rivers of Kerala having several purification units for drinking water in the province.

Non-target screening and prioritization of potentially persistent, bioaccumulating and toxic domestic wastewater contaminants and their removal in on-site and large-scale sewage treatment plants

On-site sewage treatment facilities (OSSFs), which are used to reduce nutrient emissions in rural areas, were screened for anthropogenic compounds with two-dimensional gas chromatography-mass spectrometry (GC×GC-MS). The detected compounds were prioritized based on their persistence, bioaccumulation, ecotoxicity, removal efficiency, and concentrations. This comprehensive prioritization strategy, which was used for the first time on OSSF samples, ranked galaxolide, α-tocopheryl acetate, octocrylene, 2,4,7,9-tetramethyl-5-decyn-4,7-diol, several chlorinated organophosphorus flame retardants and linear alkyl benzenes as the most relevant compounds being emitted from OSSFs. Twenty-six target analytes were then selected for further removal efficiency analysis, including compounds from the priority list along with substances from the same chemical classes, and a few reference compounds. We found significantly better removal of two polar contaminants 2,4,7,9-tetramethyl-5-decyn-4,7-diol (p=0.0003) and tris(2-butoxyethyl) phosphate (p=0.005) in soil beds, a common type of OSSF in Sweden, compared with conventional sewage treatment plants. We also report median removal efficiencies in OSSFs for compounds not studied in this context before, viz. α-tocopheryl acetate (96%), benzophenone (83%), 2-(methylthio)benzothiazole (64%), 2,4,7,9-tetramethyl-5-decyn-4,7-diol (33%), and a range of organophosphorus flame retardants (19% to 98%). The environmental load of the top prioritized compounds in soil bed effluents were in the thousands of nanogram per liter range, viz. 2,4,7,9-tetramethyl-5-decyn-4,7-diol (3000ngL^-1), galaxolide (1400ngL^-1), octocrylene (1200ngL^-1), and α-tocopheryl acetate (660ngL^-1).

Multi-residue method for the determination of over 400 priority and emerging pollutants in water and wastewater by solid-phase extraction and liquid chromatography-time-of-flight mass spectrometry

This article describes the development and validation of a liquid chromatography high-resolution mass spectrometry method for the simultaneous determination of over 400 multi-class priority and emerging pollutants with different physicochemical properties in environmental waters (surface water and wastewater). The proposed approach is based on the use of a database consisting of retention time/exact mass (of selected ions) pairs implemented with specific software for data analysis. The targeted list comprises 430 contaminants belonging to different compound categories, including 105 multiclass pharmaceuticals (analgesics/anti-inflammatories, antibiotics, lipid regulators, β-blockers, antiepileptic/psychiatrics ulcer healings, diuretics, hormones and bronchodilatadors), life-style products (caffeine, nicotine), 21 drugs of abuse and their metabolites, 279 pesticides and some of their more relevant metabolites, nitrosamines, flame retardants, plasticizers and perfluorinated compounds. The proposed approach included a simple offline solid phase extraction (SPE) step using polymeric cartridges (Oasis HLB) with 200mL of water sample loaded, followed by analysis by rapid resolution liquid chromatography electrospray time-of-flight mass spectrometry (LC-TOFMS) in both positive and negative modes. The identification of the positive findings is accomplished with the data from accurate masses of the target ions along with retention time data and characteristic in-source fragment ions. The overall method performance was satisfactory with limits of quantification lower than 10ngL(-1) for the 44% of studied compounds. Recoveries between 50% and 130% were obtained for the 65% of the analytes (281 compounds). Matrix effects occurring with wastewater matrices were also assessed. The developed method was applied to the determination of target analytes in real surface water and wastewater samples.

Monitoring of selected priority and emerging contaminants in the Guadalquivir River and other related surface waters in the province of Jaén, South East Spain

The province of Jaén counts with four natural parks, numerous rivers, reservoirs and wetlands; moreover, it is probably the region with higher olive oil production in the world, which makes this zone a proper target to be studied based on the European Water Framework Directive 2000/60/CE. The aim of this survey is to monitor a total number of 373 compounds belonging to different families (pesticides, PAHs, nitrosamines, drugs of abuse, pharmaceuticals and life-style compounds) in surface waters located at different points of the province of Jaén. Among these compounds some priority organic substances (regulated by the EU Directive 2008/105/EC) and pollutants of emerging concern (not regulated yet) can be found. A liquid chromatography electrospray time-of-flight mass spectrometry (LC-TOFMS) method covering 340 compounds was developed and applied, together with a gas chromatography triple-quadrupole mass spectrometry (GC-MS/MS) method which enabled the analysis of 63 organic contaminants (30 of these compounds are analyzed by LC-TOFMS as well). From April 2009 to November 2010 a total of 83 surface water samples were collected (rivers, reservoirs and wetlands). In this period numerous organic contaminants were detected, most of them at the ng L(-1) level. The most frequently priority substances found were chlorpyrifos ethyl, diuron and hexachlorobenzene. Within the other groups, the most frequently detected compounds were: terbuthylazine, oxyfluorfen, desethyl terbuthylazine, diphenylamine (pesticide family); fluorene, phenanthrene, pyrene (PAHs group), codeine, paracetamol (pharmaceuticals compounds) and caffeine, nicotine (life-style compounds). As is could be expected, the total concentration of emerging contaminants is distinctly larger than that of priority pollutants, highlighting the importance of continuing with the study of their presence, fate and effects in aquatic environments. However, concentration levels (at the ng per liter level) are low in general for both kinds of contaminants which minimizes the possible harmful effect on the environment.

Comparative evaluation of liquid-liquid extraction, solid-phase extraction and solid-phase microextraction for the gas chromatography-mass spectrometry determination of multiclass priority organic contaminants in wastewater

The European Water Framework Directive (WFD) 2000/60/EC establishes guidelines to control the pollution of surface water by sorting out a list of priority substances that involves a significant risk to or via the aquatic systems. In this article, the analytical performance of three different sample preparation methodologies for the GC-MS/MS determination of multiclass organic contaminants-including priority comprounds from the WFD-in wastewater samples using gas chromatography-mass spectrometry was evaluated. The methodologies tested were: (a) liquid-liquid extraction (LLE) with n-hexane; (b) solid-phase extraction (SPE) with C18 cartridges and elution with ethyl acetate:dichloromethane (1:1 (v/v)), and (c) headspace solid-phase microextraction (HS-SPME) using two different fibers: polyacrylate and polydimethylsiloxane/carboxen/divinilbenzene. Identification and confirmation of the selected 57 compounds included in the study (comprising polycyclic aromatic hydrocarbons (PAHs), pesticides and other contaminants) were accomplished using gas chromatography tandem mass spectrometry (GC-MS/MS) with a triple quadrupole instrument operated in the multiple reaction monitoring (MRM) mode. Three MS/MS transitions were selected for unambiguous confirmation of the target chemicals. The different advantages and pitfalls of each method were discussed. In the case of both LLE and SPE procedures, the method was validated at two different concentration levels (15 and 150 ng L(-1)) obtaining recovery rates in the range 70-120% for most of the target compounds. In terms of analyte coverage, results with HS-SPME were not satisfactory, since 14 of the compounds tested were not properly recovered and the overall performance was worse than the other two methods tested. LLE, SPE and HS-SPME (using polyacrylate fiber) procedures also showed good linearity and precision. Using any of the three methodologies tested, limits of quantitation obtained for most of the detected compounds were in the low nanogram per liter range.