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Many biological activities have been reported for the Ilex genus. However, few studies in the literature have reported on guayusa. To address this gap in our knowledge, chemical analysis of guayusa leaves was made. Extracts were obtained by applying Soxhlet, maceration, supercritical CO2 and pressurised liquid extraction techniques, using water and ethanol as solvent/cosolvent. Extracts were evaluated for their phenolic content and antioxidant capacity. The chemical profile was obtained from HPLC. In raw guayusa leaves were identified caffeine (2.27 ± 0.05%), protein (15.31 ± 0.07%) and lipids (11.81 ± 0.14%). Extracts presented the highest phenolic content (156.56 ± 1.32 mg GAE g−1) and the best antioxidant activity (EC50= 61.85 ± 0.21 µg mL−1) when water was used as solvent/cosolvent. Through HPLC, three main substances were determined and quantified in the extracts: caffeine, theobromine and 5-caffeoylquinic acid. Based on these results, guayusa may be considered a natural source of compounds with potential application in the food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

The use of psychoactive substances, including illegal drugs, drugs of abuse and psychiatric pharmaceuticals, is a major health and environmental issue. In particular, drugs are found in urban sewage and water ecosystems. The analysis of drugs in wastewater is challenging because drugs occur at trace levels in complex organo-mineral media, calling for advanced analytical methods. Here we review recent methods developped to analyze drugs in sludge, sediments, soils and biota. Extraction methods include solid–liquid extraction, sonication, microwave, and quick, easy, cheap, effective, rugged and safe extraction (QuEChERS). We compare and discuss advantages and disadvantages of each analytical step for various sample types. [ABSTRACT FROM AUTHOR]

Valorisation of food by-products has recently attracted considerable attention due to the opportunities to improve the economic and environmental sustainability of the food production chain. Large quantities of non-edible parts of the artichoke plant (Cynara cardunculus L.) comprising leaves, stems, roots, bracts, and seeds are discarded annually during industrial processing. These by-products contain many phytochemicals such as dietary fibres, phenolic acids, and flavonoids, whereby the most challenging issue concerns about the recovery of high-added value components from these by-products. The aim of this work is to develop a novel valorisation strategy for the sustainable utilisation of artichoke leaves' waste, combining green pressurised-liquid extraction (PLE), spectrophotometric assays and UPLC–HRMS phytochemical characterization, to obtain bioactive-rich extract with high antioxidant capacity. Multivariate analysis of the major selected metabolites was used to compare different solvent extraction used in PLE. [ABSTRACT FROM AUTHOR]

Background: Polyphenols are a set of bioactive compounds commonly found in plants. These compounds are of great interest, as they have shown high antioxidant power and are correlated to many health benefits. Hence, traditional methods of extraction such as solvent extraction, Soxhlet extraction and novel extraction technologies such as ultrasound-assisted extraction and subcritical water extraction (SWE) have been investigated for the extraction of polyphenols. Scope and Approach: Generally, for traditional extractions, the total phenolic content (TPC) is highest at an extraction temperature of 60–80 °C. For this reason, polyphenols are regularly regarded as heat-labile compounds. However, in many studies that investigated the optimal temperature for subcritical water extraction (SWE), temperatures as high as 100–200 °C have been reported. These SWE extractions showed extremely high yields and antioxidant capacities at these temperatures. This paper aimed to examine the relevant literature to identify and understand the mechanisms behind this discrepancy. Results: Thermal degradation is the most common explanation for the degradation of polyphenols. This may be the case for specific or sub-groups of phenolic acids. The different extraction temperatures may have also impacted the types of polyphenols extracted. At high extraction temperatures, the formation of new compounds known as Maillard reaction products may also influence the extracted polyphenols. The selection of source material for extraction, i.e., the plant matrix, and the effect of extraction conditions, i.e., oxidation and light exposure, are also discussed. The overestimation of total phenolic content by the Folin–Ciocâlteu assay is also discussed. There is also a lack of consensus in TPC's correlation to antioxidant activity. [ABSTRACT FROM AUTHOR]

Valorisation of food by-products has recently attracted considerable attention due to the opportunities to improve the economic and environmental sustainability of the food production chain. Large quantities of non-edible parts of the artichoke plant (Cynara cardunculus L.) comprising leaves, stems, roots, bracts, and seeds are discarded annually during industrial processing. These by-products contain many phytochemicals such as dietary fibres, phenolic acids, and flavonoids, whereby the most challenging issue concerns about the recovery of high-added value components from these by-products. The aim of this work is to develop a novel valorisation strategy for the sustainable utilisation of artichoke leaves’ waste, combining green pressurised-liquid extraction (PLE), spectrophotometric assays and UPLC–HRMS phytochemical characterization, to obtain bioactive-rich extract with high antioxidant capacity. Multivariate analysis of the major selected metabolites was used to compare different solvent extraction used in PLE.

Introduction: Radix Astragali, the dried root of Astragalus membranaceus (Fish.) Bge. (family Fabaceae), which is known as Huangqi in China, has been proven to be an immunostimulant, diuretic, antidiabetic, analgesic, and it has also been used as a health food supplement in some Asian populations and also serves as a lead herb in many traditional Chinese medicine formulations as well as in Chinese ethnic tonifying soups. Objective: Screening and purification of bioactive compounds from natural products is challenging work due to their complexity. We present the first report on the use of pressurised liquid extraction and on‐line two‐dimensional counter current chromatography as an efficient medium for scaled‐up extraction and separation of six bioactive compounds from Astragalus membranaceus. Method: We applied the established method with ultrafiltration‐liquid chromatography to screen acetylcholinesterase inhibitors, which were then evaluated and confirmed for anti‐Alzheimer activity using PC12 cell model. Results: Six major compounds, namely, calycosin‐7‐O‐β‐d‐glucoside, pratensein‐7‐O‐β‐d‐glucoside, formononetin‐7‐O‐β‐d‐glucoside, calycosin, genistein, and formononetin, with acetylcholinesterase binding affinities were identified and isolated from the raw plant materials via two sets of n‐hexane/ethyl acetate/0.2% acetic acid (first‐stage counter current chromatography) and n‐hexane/ethyl acetate/methanol/water (second‐stage counter current chromatography) solvent systems: 1.87:1.0:1.33 and 5.62:1.0:2.42:5.25, v/v/v/v, which were optimised by a mathematical model. Conclusion: Therefore, a useful platform for the large‐scale production of bioactive and nutraceutical ingredients was developed herein. With the on‐line system developed here, we present a feasible, selective, and effective strategy for rapid screening and identification of enzyme inhibitors from complex mixtures. Ultrafiltration with liquid chromatography is an efficient method that can be applied to rapidly screen and identify the ligands from Astragalus membranaceus. A continuous online method comprised of pressurised liquid extraction, 2‐dimensional countercurrent chromatography was developed for the efficient scaled‐up production of six compounds with high purities. The use of bioactivity screening method combined with preparation method of bioactive compounds facilitated the efficient screening and isolation of the acetylcholinesterase inhibitors from complex samples. [ABSTRACT FROM AUTHOR]

Background: Polyphenols are a set of bioactive compounds commonly found in plants. These compounds are of great interest, as they have shown high antioxidant power and are correlated to many health benefits. Hence, traditional methods of extraction such as solvent extraction, Soxhlet extraction and novel extraction technologies such as ultrasound-assisted extraction and subcritical water extraction (SWE) have been investigated for the extraction of polyphenols. Scope and Approach: Generally, for traditional extractions, the total phenolic content (TPC) is highest at an extraction temperature of 60–80 °C. For this reason, polyphenols are regularly regarded as heat-labile compounds. However, in many studies that investigated the optimal temperature for subcritical water extraction (SWE), temperatures as high as 100–200 °C have been reported. These SWE extractions showed extremely high yields and antioxidant capacities at these temperatures. This paper aimed to examine the relevant literature to identify and understand the mechanisms behind this discrepancy. Results: Thermal degradation is the most common explanation for the degradation of polyphenols. This may be the case for specific or sub-groups of phenolic acids. The different extraction temperatures may have also impacted the types of polyphenols extracted. At high extraction temperatures, the formation of new compounds known as Maillard reaction products may also influence the extracted polyphenols. The selection of source material for extraction, i.e., the plant matrix, and the effect of extraction conditions, i.e., oxidation and light exposure, are also discussed. The overestimation of total phenolic content by the Folin–Ciocâlteu assay is also discussed. There is also a lack of consensus in TPC’s correlation to antioxidant activity.

We have developed an analytical method based on pressurised liquid extraction (PLE) followed by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) for the simultaneous determination of five phthalate diesters and six phthalate monoesters in widely consumed seafood species. In order to obtain the highest extraction recoveries, as well as to reduce the matrix effect of such complex samples, the most important extraction parameters were optimised and several clean-up and preconcentration strategies were tested. This method provided limits of detection that ranged from 1 to 25 ng g−1 dry weight (d.w.) for most compounds in both fatty and low-fat species. Moreover, several target analytes were quantified in five seafood species (four phthalate diesters and three of their metabolites). The most abundant compounds were diethyl phthalate (DEP) and diethylhexyl phthalate (DEHP), which were quantified from 60 to 3393 ng g−1 (d.w.) and from 117 to 1562 ng g−1 (d.w.), respectively. [ABSTRACT FROM AUTHOR]

A sensitive and reliable method using pressurised liquid extraction (PLE) followed by molecularly imprinted solid phase extraction (MISPE) and high performance liquid chromatography with fluorescence detection (HPLC-FLD) has been developed for the analysis of alternariol (AOH) and alternariol monomethyl ether (AME) in tomato samples. Influence of several extraction parameters that affect PLE efficiency were evaluated for the simultaneous extraction of both mycotoxins in the selected samples. AOH and AME were optimally extracted using MeOH/water (25:75, v/v) at 70°C as solvent, a pressure of 1000 psi and a single extraction cycle. The resulting PLE extracts were pre-concentrated by molecularly imprinted solid phase extraction (MISPE) cartridges followed of analysis by HPLC with fluorescence detection (λexc = 258, λem = 440 nm). The proposed method was applied to the analysis of AOH and AME in fortified tomato samples (20-72 µg· kg-1) with recoveries of 84-97% (RSD < 8%, n = 6) for AOH and 67-91% (RSD < 13%, n = 6) for AME. The detection limit for AOH and AME were 7 and 15 µg· kg-1, respectively. The ensuing PLE-MISPE-HPLC-FLD method was validated for the analysis of both mycotoxins in tomato samples in accordance with European Commission Decision 2002/657/EC. [ABSTRACT FROM AUTHOR]

The metabolism of seaweeds depends on environmental parameters, the availability of nutrients, and biotic/abiotic stresses; therefore, their chemical composition fluctuates throughout the year. This study investigated seasonal variations in the metabolome of the Baltic Sea brown alga Fucus vesiculosus and its potential relation to the bioactivity profile. By using a definitive screening design (DSD) combined with pressurised liquid extraction (PLE), an optimised protocol was developed to extract algal biomass monthly for a full calendar year. An untargeted metabolomics approach using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MSn)-based molecular networking and manual dereplication was employed. The extracts were simultaneously screened for their in vitro antimicrobial, anticancer/apoptotic, and free radical scavenging activities. 44 compounds were putatively dereplicated in the metabolome. Many compounds were found to vary with the sampling month; phlorotannin total ion count (TIC) was highest in summer, whilst chlorophylls, lipids, and carotenoids peaked in winter and spring. The greatest radical scavenging and apoptotic activities against pancreas cancer cells observed in the summer months were attributed to high phlorotannin TIC. Methicillin-resistant Staphylococcus aureus (MRSA) inhibitory activity was produced year-round without a clear seasonal trend. This is the first study applying DSD-based optimised PLE extraction combined with a metabolome analysis of F. vesiculosus for the identification of seasonal variations in both metabolome and bioactivity.

Pressurised liquid extraction (PLE) of antioxidant compounds from bitter gourd fruits ( Momordica charantia) in aqueous ethanolic solvent was investigated using response surface methodology at laboratory scale to understand key impact of extraction variables. Extraction efficiency was optimised by measuring the yield of extraction, total phenolic content (TPC), total flavonoid content (TFC), ferric reducing/antioxidant power assay (FRAP) and radical scavenging activity (RSA). The optimal extraction conditions were reached at 80% ethanol concentration, 10-min extraction time and at 160 °C. Under these extraction conditions, values of TPC (5.40 ± 0.30 g GAE per 100 g), TFC (1.50 ± 0.10 g QE per 100 g), FRAP (778.55 ± 10 μmol eq Fe (II) g−1), yield (178.50 ± 5.50 mg g−1 dc) and RSA (75.50 ± 4.50%) were achieved. Furthermore, statistical analysis revealed that antioxidative attributes of bitter gourd extract were strongly and positively correlated with extraction temperature and ethanol concentration rather than processing time. This study illustrated that PLE has the potential to extract antioxidant compounds from tropical fruit vegetables in an accelerated manner. Furthermore, influential parameters affecting the process could be optimised for further industrial intake. [ABSTRACT FROM AUTHOR]

Iodinated X-ray contrast media (ICM-XR) are a group of pharmaceuticals widely used in medicine. Due to their low biodegradation rate, which makes their removal at wastewater treatment plants difficult, and the high doses at which they are administered, they have been detected in aquatic environments. In the present paper, a method for the quantitative determination of a group of ICM-XR in different fish species was developed and validated for the first time. Two extraction techniques were compared: pressurised liquid extraction (PLE) and QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe), with PLE being selected, followed by liquid chromatography-high resolution mass spectrometry. In addition, several clean-up strategies were evaluated. The optimised method provided PLE recoveries ranging from 60% to 88% and limits of detection ranging from 5 ng/g to 25 ng/g (dry weight). The method was applied in order to evaluate the presence of the selected ICM-XR in different fish species. [ABSTRACT FROM AUTHOR]

An analytical method based on pressurised liquid extraction (PLE) followed by liquid chromatography-high resolution mass spectrometry (Orbitrap) was developed for the simultaneous determination of ten high-intensity sweeteners in fish samples. As the method was developed, the different PLE parameters were optimised and different clean-up strategies were evaluated, of which in-cell clean-up using alumina and on-cell clean-up with hexane were the most effective. PLE recoveries were between 43% and 94%. The method quantification limits were between 12.5 ng g −1 dry weight (d.w.) and 250 ng g −1 (d.w.) and the method detection limits between 2.5 ng g −1 (d.w.) and 125 ng g −1 (d.w.). Intra-day precision and inter-day precision were below 16% and 25%, respectively. Fish samples from different species were analysed and, saccharin was found below its method quantification limit in the species Scomber scombrus (Atlantic mackerel). [ABSTRACT FROM AUTHOR]

Various extraction schemes, methods and solvents, including supercritical fluid extraction with carbon dioxide (SFE–CO 2 ) and pressurised liquid extraction (PLE) were studied for valorising Bergenia crassifolia roots and leaves as a source of natural antioxidants. It was shown that application of SFE–CO 2 and PLE schemes with different solvents and process parameters may provide several fractions, in total constituting >66% of soluble substances from the roots and >48 from the leaves. Total phenolic content (TPC), trolox equivalent antioxidant capacity (TEAC) in scavenging ABTS + and oxygen radical absorbance capacity (ORAC) activities of extracts and solid plant materials were determined. Consecutive extractions with increasing polarity solvents enabled to isolate different amounts of antioxidants. Generally, in case of roots higher antioxidant capacity values were obtained with acetone, while in case of leaves hydroethanolic solvent gave higher values. Considering that protic solvents were applied for re-extracting the residues they were proved as effective solvents for exhaustive processing of plant material. The extracts inhibited oxidation of rape seed oil and its emulsion at 120 °C as measured by the Oxipres and Rancimat methods. The major phytochemicals, namely bergenin, catechin gallate, ellagic acid and quercetin 3–β–D glucoside were quantified in B. crassifolia leaf and root extracts by UPLC/ESI–QTOF–MS; the roots contained several times higher concentrations of these compounds than the leaves, except for ellagic acid, which was not detected in the roots. The results obtained are expected in assisting to increase the prospects of expanding the cultivation of B. crassifolia as a promising industrial crop for developing various specialty natural products. [ABSTRACT FROM AUTHOR]

A multiresidue analytical method based on pressurised liquid extraction and gas-chromatography mass spectrometry was developed to determine 22 compounds belonging to different chemical families in indoor dust.: Seven organophosphate esters, six phthalate esters, three benzotriazoles, five benzothiazoles and four benzenesulfonamides were included in the present study, all of them belonging to the category of high production volume chemicals (HPVCs). Apparent recoveries ranged between 45% and 123% and method quantification limits ranged from 0.03 μg/g to 3.8 μg/g. The occurrence of the selected HPVCs was evaluated in indoor dust from different locations in the Tarragona (Catalonia, Spain) region. Two benzenesulfonamides, ortho-toluenesulfonamide and para-toluenesulfonamide, were detected in dust samples for the first time. Phthalate esters and organophosphate esters were the most abundant compounds found, and di-(2-ethylhexyl) phthalate (DEHP) was determined at the highest concentrations. With the data obtained, human exposure was assessed by calculating the estimated daily intakes (EDI) via ingestion and dermal contact. Non-carcinogenic and carcinogenic risk assessments found no risks in any of the scenarios tested, which included two age classes (children and adults) and two possible exposure scenarios (median and worst-case scenario), except for the evaluation of carcinogen risk due to ingestion of DEHP in the worst-case scenario. [Display omitted] • New multiresidue method based on PLE/GC-MS to determine 22 HPVCs in indoor dust. • Phthalate and organophosphate esters were the most abundant HPVCs. • Two benzenesulfonamides were detected in dust for the first time. • EDI ingestion and EDI dermal were evaluated. • Both non-carcinogenic and carcinogenic risk were assessed. [ABSTRACT FROM AUTHOR]

Polybrominated diphenyl ethers (PBDEs) have become ubiquitous environmental contaminants due to their incorporation into many consumer products. Their ability to bioaccumulate to alarming levels in fat-rich matrices such as fish demands fast and efficient methods to monitor these contaminants. We present an analytical method for selective-pressurised liquid extraction (S-PLE) of PBDEs from fish tissue. Fat removal performance of different mixtures of Florisil, silica gel and sulphuric acid-impregnated silica gel were evaluated using a response surface experimental design approach for determining the optimal fat-retaining mixture for S-PLE. Acid-silica gel had the greatest individual effect on fat retention; with a two-thirds acid-silica one-third Florisil mixture found to be the most efficient (>97%). Method validation was performed using recovery experiments at three spiked concentration levels (0.05, 0.5 and 5 ng g −1 ww). Mean recoveries of target analytes in spiked samples ranged from 70 to 124%, with relative standard deviations <27%. The S-PLE lipid removal efficiency combined with the sensitivity of triple quadrupole mass spectrometers provides a fast and comparatively inexpensive analytical method for analysis of PBDEs in fish samples. [ABSTRACT FROM AUTHOR]

Musk compounds are widely used as fragrances in personal care products. On account of their widespread use and their low biodegradation, they can be found in environmental samples. In our study two extraction methodologies were compared and different clean-up strategies were also studied in order to develop a reliable analytical method, with minimum matrix effect and good detection limits, to determine synthetic musk fragrances- six polycyclic musks, three nitro musks and the degradation product of one polycyclic musk- in fish and mussel samples. The first extraction technique involves a QuEChERS extraction, a consolidate extraction methodology in the field of food analysis of growing interest over recent years, followed by a dispersive solid-phase extraction (dSPE) as clean-up strategy. The second extraction technique consists of a conventional pressurised liquid extraction (PLE) with dichloromethane and an in-cell clean-up to decrease the matrix effect and remove the undesired components ⁎ present in PLE extracts. Large volume injection (LVI) followed by gas chromatography-ion trap-tandem mass spectrometry (GC-IT-MS/MS) was chosen as the separation and detection technique. Validation parameters, such as method detection limits and method quantification limits were found at ng g −1 levels for both fish and mussel matrices. Good levels of intra-day and inter-day repeatabilities were obtained analysing fish and mussel samples spiked at 50 ng g −1 (d.w.) ( n =5, RSDs<17%). The developed PLE/GC-IT-MS/MS method was successfully applied to determine the target musk fragrances present in fish and mussel samples from the local market in Tarragona and fish samples from the Ebro River. The results showed the presence of galaxolide (2.97–18.04 ng g −1 (d.w.)) and tonalide (1.17–8.42 ng g −1 (d.w.)) in all the samples analysed, while the remaining polycyclic musks such as cashmeran, celestolide and phantolide, were only detected in some of the fish samples analysed. None of the samples analysed contained detectable traces of the nitro musks studied. [ABSTRACT FROM AUTHOR]

To assess soil contamination, it is important to be able to measure different classes of pesticides simultaneously. For this reason we developed a sensitive ultra-high-performance liquid chromatography–tandem mass spectrometry method for the simultaneous analysis of 25 pesticides in soil samples. Multi-class pesticides (triazines, phenylureas, phenoxy acid pesticides etc.) were analysed using a single mass spectrometry method with a fast polarity switching option, allowing the analysis of 19 compounds in the positive ionisation mode and six compounds in the negative ionisation mode. Extraction of pesticides from soil samples was performed employing a pressurised liquid extraction (PLE) and a quick, easy, cheap, effective, rugged and safe (QuEChERS) procedure, recently developed for the extraction of multi-residue pesticides from food matrices. The extraction efficiency, performance and recoveries of these two procedures were evaluated and compared. In addition, we studied the effect of matrix on signal suppression or enhancement. Isotope-labelled internal standards (ILIS) were used to compensate the suppression or enhancement of signal intensities in the extracted samples. The method was validated using reference soil material (EUROSOIL 7) spiked with 50 μg/kg of each pesticide. The average recovery by PLE varied between 65.1% and 122.2% with RSDs of 1.7–23.4%. QuEChERS provided better recoveries for most of the pesticides, the extraction recovery ranging from 79.4% to 113.3% with RSDs of 1.0–12.2%. Limits of quantification for all target compounds were within a range of 0.1–2.9 µg/kg. [ABSTRACT FROM PUBLISHER]

An analytic method was developed and validated for the analysis of chlordecone in the three main types of French West Indies soils: Ferralsol, Andosol and Nitisol with and without the addition of Daramend® and compost amendment used in a remediation process. The method consists in analysis by gas chromatography coupled with triple quadrupole mass spectrometry after pressurised liquid extraction. The high natural content of organic matter in the soils coupled with the additional exogenous organic matter from the amendments tested lead to a complex extract. Trans-nonachlor was used as surrogate to correct the results for extraction efficiency, and C chlordecone was added as internal standard to mimic as closely as possible the behaviour of chlordecone and suppress possible side effects during its analysis. The key parameters of the method (linearity, repeatability, interday precision, specificity, extraction efficiency and limit of quantification) were validated in accordance with the NF T 90-210 standard method. The limit of quantification is 0.03 mg/kg. Uncertainty ( k = 2) was 40 % for concentrations lower than or equal to 1 mg/kg, and 30 % for concentrations greater than 1 mg/kg. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Highlights: [•] Artificial sweeteners extraction by PLE with water followed by SPE. [•] Procedure easy to perform and environmentally friendly. [•] Satisfactory LOQs between 0.3 and 16ng/g dry weight. [•] Application to sewage sludge from WWTPs. [•] The most frequently detected compounds were ACE, CYC and SUC. [Copyright &y& Elsevier]

Abstract: N-nitrosamines are potentially hazardous pollutants, classified as probable carcinogenic and mutagenic by the U.S. Environmental Protection Agency (EPA). In this paper, the presence of these pollutants was studied in air samples taken at different locations of Tarragona (urban and harbour). As a result, a reliable method has been developed for determining N-nitrosamines and nicotine based on pressurised liquid extraction (PLE) and gas chromatography-(chemical ionisation) ion trap tandem mass spectrometry (GC-(CI)MS/MS). The chromatographic analysis enables the determination of these compounds in less than 13min with total separation and good resolution between the compounds. Recovery values were higher than 80% for most of the compounds and the repeatability of the method was under 18% (5ngm−3, %RSD, n=4). MDLs were between 0.1ngm−3 (NMor and NPip) and 2ngm−3 (NMEA). NMor, NPyr, NPip and nicotine were the most frequent compounds in urban and harbour samples at concentration levels between 0.3ngm−3 (NPyr) and 12.5ngm−3 (nicotine) and between 0.13ngm−3 (NPyr) and 3.8ngm−3 (nicotine), respectively. [Copyright &y& Elsevier]

Abstract: In this work, we reported a novel application of pressurised liquid extraction (PLE) on coffee bean. The condition of PLE was carefully optimised with the aid of response surface methodology (RSM) including adjustment of experimental parameters (solvent type and sample to hydromatrix ratio) and other operating parameters (i.e. temperature (50–100°C), pressure (1000–2000psi) and static extraction time (5–15min)). The coffee extracts obtained under three different extraction conditions were evaluated through descriptive sensory analysis. Then, the results showed that those targeted compounds obtained from PLE were nearly three times higher (1473ppm) than conventional solvent extraction (571ppm). Thus, PLE demonstrated the feasibility of producing a series of coffee extracts under controllable extraction conditions in correlation with desirable sensory attributes. This approach has not previously reported to characterise the aroma of coffee bean. [Copyright &y& Elsevier]

Abstract: A method for the determination of five polyether ionophores in urban sewage sludge has been developed. The extraction of compounds was performed by pressurised liquid extraction using acetone, while florisil was used for in-cell clean-up to minimise the matrix effect in the sludge extracts. An amide polar-embedded reversed-phase column was used for the chromatographic separation with a rapid-resolution liquid chromatograph coupled to a tandem mass spectrometer. Moreover, several clean-up strategies such as in-cell and on-cell clean-up and solid-phase extraction clean-up, among others, were tested and their results are discussed in the present paper. Recoveries (10 and 250μg/kg in dry weight (d.w.), n =6) were close to 90%, repeatability and reproducibility (%RSD, 10 and 250μg/kg (d.w.), n =6) were less than 10% and12%, respectively. Limits of detection (LODs) and limits of quantification (LOQs) ranged between 0.5 and 1μg/kg (d.w.) and between 1 and 5μg/kg (d.w.), respectively. The method was applied to samples collected in five sewage treatment plants in Catalonia. Monensin and narasin were determined in some sludge samples at concentrations from

The efficiencies of pressurised liquid extraction ( PLE) and a traditional solid-liquid extraction ( SLE) at extracting antioxidant polyphenols from Irish macroalgae Ascophyllum nodosum, Pelvetia canaliculata, Fucus spiralis and Ulva intestinalis were compared. PLE was more effective for extracting polyphenols with acetone/water (80:20); however, when food-friendly solvents of ethanol/water (80:20) and water were employed, SLE resulted in higher phenolic content in brown macroalgal extracts. For example, the Fucus spiralis SLE water and ethanol/water extracts displayed total phenolic contents ( TPCs) of 130.58 ± 2.78 and 142.81 ± 1.77 μg phloroglucinol equivalents ( PGE) mg−1 sample, respectively, compared with TPCs of 90.79 ± 1.16 and 124 ± 6.54 μg PGE mg−1 sample for the corresponding PLE extracts. All SLE aqueous ethanolic macroalgal extracts possessed higher DPPH radical scavenging abilities ( RSA) and ferric reducing antioxidant power ( FRAP) than their PLE equivalents . This study indicates that the application of high extraction temperatures (50-200 °C) and pressures (500-3000 psi) used in PLE does not enhance the antioxidant activities of macroalgal extracts relative to SLE extraction. The ability to produce antioxidant food-friendly macroalgal extracts using SLE could represent significant cost reductions on an industrial scale further enhancing the potential of macroalgal polyphenols to be used in functional food preparations. [ABSTRACT FROM AUTHOR]

Abstract: Glucocorticoids are a type of steroid hormones classified as endocrine disrupting chemicals (EDCs) and they are widely used by human and animal medicine. In this paper, we describe the development and validation of an analytical method for the determination of 9 selected glucocorticoids (betamethasone, cortisol (hydrocortisone), cortisone, dexamethasone, flumethasone, methylprednisolone, prednisolone, prednisone and triamcinolone acetonide) in sewage sludge by pressurised liquid extraction (PLE) and ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS). PLE with on-cell clean-up followed by solid-phase extraction (SPE) clean-up (Oasis HLB) has been applied to extract the analytes and clean up the matrix. Recoveries of the method were from 8% for prednisone and cortisone to 73% for triamcinolone acetonide. The developed method achieves limits of detection (LODs) between 1 and 5μg/Kg dry weight (d.w.) in sludge and the repeatability expressed as relative standard deviation (%RSD, 50μg/Kg (d.w.), n=3) is less than 8%. The PLE/SPE/UHPLC-MS/MS method was successfully applied to determine these pollutants in sludge samples from two sewage treatment plants located in the Tarragona area. Cortisone was found at levels below LOQ, cortisol between 5.2 and 6.1μg/Kg (d.w.) and prednisolone between

Abstract: A method based on gas chromatography–mass spectrometry (GC–MS) combined with a pressurised liquid extraction (PLE) to determine four organophosphates, seven phthalate esters and bis(2-ethylhexyl) adipate in particulated material of harbour air samples has been developed. Some studies show that these compounds may cause hormone disrupting effects on human health. Moreover, the U.S. Environmental Protection Agency (EPA) has classified benzyl butyl phthalate and di(2-ethylhexyl) phthalate as possible human carcinogens.The chromatographic time per run analysis is less than 15min and the complete separation of all compounds is achieved. The PLE was optimised with recoveries above 90% and the repeatability of the method with real samples is less than 11% (%RSD, n=4). The MDLs (0.004–0.4ngm−3) and MQLs (0.02–2ngm−3) are limited by the fact of some compounds are present in low levels in sampling blank filters.The method was successfully applied in several samples and most of the compounds under study were found. The most relevant values were the high concentration of di-iso-butyl phthalate (between 28 and 529ngm−3) and the significant concentration of di(2-ethylhexyl) phthalate (between MQL and 22ngm−3). In addition, benzyl butyl phthalate was also detected in some samples but at low concentration levels (between MQL to 0.2ngm−3). [Copyright &y& Elsevier]

Abstract: The development and characterisation of a method based on reverse-phase ultra-performance liquid chromatography (UPLC) coupled to a quadrupole-time of flight mass spectrometer (Q-TOF-MS) with negative electrospray ionisation (ESI) to determine perfluorinated compounds (PFCs) in packaging is presented in this paper. Analytes were quantitatively recovered from packaging with methanol in only one PLE cycle of 6min at 100°C. The UPLC allowed the successful separation of the studied PFCs in less than 4min. The whole method presented good precision, with RSDs below 8%, LODs from 0.6 to 16ngg−1; and excellent recovery values, around 100% in all cases, were achieved. The PLE–UPLC–MS method was applied to the analysis of popcorn packaging for microwave cooking. Besides the most commonly studied PFCs: PFOA and PFOS, the presence of other perfluorocarboxylic acids (PFCAs) in popcorn packaging is evidenced in this work. [Copyright &y& Elsevier]

ABSTRACT Introduction Macleaya microcarpa (Papaveraceae family) has been of considerable interest in recent years as a prospective source of quaternary benzo[ c]phenanthridine alkaloids (QBAs) related to many pharmaceutical beneficial effects. For this purpose, a quantitative, efficient and fast method to isolate the QBAs from the plant material is required. Objective To optimise and compare pressurised liquid extraction (PLE) with Soxhlet extraction and maceration in order to estimate extraction conditions for fast and efficient isolation of QBAs contained in the roots of Macleaya microcarpa. Methodology The QBAs were extracted by PLE, Soxhlet extraction and maceration at different conditions (solvent, time, etc.). Reversed phase HPLC with diode-array detector was utilised for their determination and quantification. To optimise the PLE procedure, the variable parameters, including temperature (40-150 °C), sample-to-inert material ratio, extraction time (5-30 min) and number of extraction cycles (1-4), were also tested. Results Quantitative determination of QBAs resulted in 0.2-2.8 mg/g, 0.3-2.5 mg/g and 0.3-3.1 mg/g for PLE, Soxhlet extraction and maceration. To produce the yields mentioned above, PLE required only up to 30 min compared with 21 h for Soxhlet extraction and 49 days for maceration. Conclusion PLE provided an effective and fast extraction of QBAs from M. microcarpa roots and can be recommended as an alternative isolation method to conventional techniques for QBAs from the plant sources. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: By-products of plant origin represent an abundant source of bioactive compounds. However, to exploit these resources commercially relevant strategies for their extraction must be developed. This review focuses on the extraction of bioactive compounds from food by-products of plant origin by a number of novel methods, including pressurised liquid extraction and supercritical CO2 extraction. In general supercritical CO2 extraction is most effective for apolar compounds such as carotenoids, while pressurised liquid extraction can be used to extract more polar compounds such as polyphenols. Both techniques are sustainable and green techniques. In addition, pre-treatment of plant by-products by novel non-thermal processing techniques in order to enhance extraction will be highlighted. In general the selection of an appropriate extraction strategy is dependent on the type of compound to be extracted as well as the potential up scaling of the technique. [Copyright &y& Elsevier]

Abstract: Pressurised liquid extraction (PLE) of three major flavones (hesperidin, nobiletin, and tangeretin) from the peels of Citrus reticulata ‘Chachi’ (Guangchenpi) was investigated. These flavones were quantified and analysed by liquid chromatography–diode array detector–electrospray ionisation mass spectrometry (LC–DAD–ESI/MS). The PLE procedure was optimised, validated and compared with other conventional extraction techniques. PLE gained the best result due to the highest extraction efficiency within the shortest extraction time. The optimal conditions of PLE were employing 70% methanol as extraction solvent at a temperature of 160°C and extraction pressure of 1500psi, using one extraction cycle with a static extraction time of 20min. MS coupling with an ESI interface in the positive ion mode was used as the detection technique. This is the first report on combining PLE with LC–DAD–ESI/MS for the extraction and quantification of flavones in Citrus reticulata ‘Chachi’. [Copyright &y& Elsevier]

Abstract: The composition of volatile and semi-volatile compounds of chestnut (Castanea sativa Mill.) was studied and compared to oak wood species frequently used in cooperage (Quercus alba, Quercus petraea, Quercus robur and Quercus pyrenaica) to evaluate its aromatic potential. Chestnut was found to be a suitable wood for use in ageing processes, based on the large, diverse number of detected compounds (e.g., lactones, furanic compounds, terpenes, lignin derivatives and triterpenic compounds). Chestnut wood possessed high levels of volatile phenols and phenolic aldehydes, specifically vanillin and its derivatives. Each wood species exhibited a characteristic, quantifiable composition of volatile compounds, and therefore, the sensorial profile of each wood species is expected to be different. The levels of certain volatile compounds were also useful for discriminating among the studied wood species. [Copyright &y& Elsevier]

Abstract: A new method based on pressurised liquid extraction (PLE) followed by liquid chromatography–triple quadrupole linear ion trap mass spectrometry (LC–QTrap-MS) analysis has been developed for the identification and quantification of four major alkaloids in extracts of Corydalis decumbens (Thunb.) Pers. PLE extractions were performed using 90% ethanol; temperature was set at 100°C and pressure at 1500psi. HPLC analysis was performed on a Waters XBridge™ C18 column (150mm×2.1mm i.d., 3.5μm) eluted by a mobile phase of acetonitrile and 0.2% acetic acid. Data acquisition was carried out in multiple reaction monitoring transitions (MRMs) mode, monitoring two MRM transitions to ensure an accurate identification of target compounds in the samples. Additional identification and confirmation of target compounds were performed using the enhanced product ion modus (EPI) of the linear ion trap. The novel LC–QTrap-MS platform offers the best sensitivity and specificity for characterization and quantitative determination of the four alkaloids in C. decumbens (Thunb.) Pers. and fulfils the quality criteria for routine laboratory application. [Copyright &y& Elsevier]

Abstract: A new analytical method, using pressurised liquid extraction (PLE) and liquid chromatography–tandem mass spectrometry (LC–MS/MS), was developed for the simultaneous determination of bisphenol A (BPA), octylphenol (OP) and nonylphenol (NP) in powdered infant formulas (IF) and powdered skimmed milk (PM). The analytes were extracted by PLE, using this optimised conditions: ethyl acetate as solvent, 70°C of temperature, reversed-phase silica C18 as dispersing agent and three cycles of extraction. The extracts were then injected in LC–MS/MS using a Gemini C18 column and a mixture of 5% water and 95% methanol/acetonitrile, both with 0.1% ammonia, as a mobile phase. Recoveries at different fortification levels (0.5 and 0.05mgkg−1), were between 89% and 92% for BPA, 84 and 98% for OP, and 93% and 101% for NP. The method was applied to the analysis of samples of PM and IF, bought in Italian and Spanish markets. In positive samples, phenols concentration ranged from 0.07 to 1.29mgkg−1 for BPA, from 0.028 to 1.55mgkg−1 for OP and from 0.026 to 1.47mgkg−1 for NP. [ABSTRACT FROM AUTHOR]

An improved, rapid method for polychlorobiphenyl (PCB) extraction from lipid rich matrices and determination by GC-MS is presented. PCBs accumulate in the environment, can be extremely persistent, and health complications including neurotoxic effects have been reported. Thus, monitoring these persistent organic pollutants seems prudent. The analytical procedure for PCB assessment from environmental samples typically consists of the three steps extraction, purification and analysis by GC coupled with electron-capture detection or mass spectrometry. The aim of the present study was the implementation of a protocol allowing for determining selected indicator PCBs (n = 6) following a single extraction/purification step. Pressurised liquid extraction (PLE) combined with different silica layers directly in the extraction cell allowed efficient removal of lipids and direct analysis by GC-MS. Accuracy was determined by comparison with a reference standard (SRM 1946), and the equivalence of PLE to an established extraction method (soxhlet) was verified. Mean recovery of the combined procedure from trout spiked with a mixture of 50 ng of each PCB was 87 ± 8 (range 74-94)%, and results of ASE were comparable to soxhlet (difference total PCBs <16%). In addition, the protocol showed higher throughput (20 min/extraction cycle) and required less organic solvents (90 mL/sample). This method was then applied for monitoring PCBs in a variety of Luxembourgish fresh water fish (trout, eels, roaches, n = 38). The PCB profile was dominated by congeners 153 and 138, with maximum concentrations of 30 and 21 ng g-1 trout (fresh weight), respectively, highlighting that PCB concentrations might vary considerably in fish depending on species, eating habits and weight. [ABSTRACT FROM AUTHOR]

Abstract: A pressurised liquid extraction (PLE) method for extraction and quantification of total fat and oil in bread and derivatives products has been proposed. Parameters implied in the extraction process; such us temperature, static time, number of extraction cycles, purge time and flush volume; have been optimised using a formal methodology based on statistical experimental design in order to obtain the best results. Moreover, this method has been validated using homemade bread elaborated in the laboratory which contained 9.64g of olive oil in 100g dry weight. The production and use of an “ad hoc” in-house reference material is just one of the most relevant aspects of this study. The uncertainty estimation has been carried out taking into account all the uncertainty components of the process and it was stated as 4.2%. Finally, the proposed method has been applied to six different Spanish bread derivatives products with different olive oil contents (5–20%) to determine the fat content. [ABSTRACT FROM AUTHOR]

This study presents a selective pressurised liquid extraction (PLE) and gas chromatography–mass spectrometry/mass spectrometry method for the determination of brominated diphenyl ethers (BDEs) in indoor dust. Selective PLE consisted of the addition of Florisil mixed with the sample in order to perform an in-cell clean-up. This approach provided a cleaner and almost colourless extract, ready to be injected in the gas chromatograph. The PLE conditions were studied using an experimental design, firstly a 4 × 3 × 2 multifactor categorical design to screen sorbent, solvent and temperature and then a central composite design to optimise sorbent mass, temperature and time. Finally, the number of extraction cycles was studied. The selected conditions were 4 g of Florisil all mixed with the sample and no additional clean-up sorbent layer, 1:1 n-hexane-dichloromethane, 60% flush volume, 40 °C, 1,500 psi, 2-min static time and one cycle. The proposed method allowed accurate determination of BDEs, with recovery values between 82% and 101% and detection limits between 0.06 and 0.24 ng g. It also has advantages over other existing methods in terms of simplicity, automation, analysis time and solvent consumption. [ABSTRACT FROM AUTHOR]

Abstract: Various extraction techniques which use fluids in super/subcritical state (CO2, H2O, CH3OH) were used for the preparation of crystalline TiO2 from surfactant-mediated titania organogels (the amorphous reaction intermediate products of surfactant-mediated sol–gel synthesis). Crystallinity, purity and texture of TiO2 powders (titania aerogels) were studied in detail for different treatment modes of titania organogels. Suitable combinations of extraction solvents and extraction temperature and pressure were considered for synthesis of TiO2 powder crystalline phase (anatase) with high specific surface area and purity (carbon content<0.1wt.%). Optimum results were achieved by combined extraction procedures—subcritical water extraction and supercritical fluid extraction or pressurised liquid extraction. Moreover, the possible tuning of the TiO2 powder pore-size distribution by regulation of temperature at constant pressure for the combined subcritical water extraction and pressurised liquid extraction was found. [Copyright &y& Elsevier]

A miniaturised pressurised liquid technique has been applied to the extraction of volatile compounds present in oak wood samples used in making wine. The solvent extraction performed at high pressure and temperature has allowed the detection of a large number of compounds some of which present sensory and antioxidant properties. The effect of the main process variables on the efficiency of extraction has been studied: the composition of the extracted fraction depended mainly on the polarity of the solvent and the extraction temperature had a high influence on the extracted amount, while the effect of static extraction time and pressure were almost negligible. The highest recoveries were obtained for dichloromethane, for two static 10-min extraction cycles at 60 °C. Among the solvent extraction techniques, miniaturised pressurised liquid extraction presents several advantages, such as the use of reduced amounts of both sample and solvent and high extraction efficiency. [ABSTRACT FROM AUTHOR]

Abstract: The study proposes an analytical method to quantify 10 alkylphenols and 12 pesticides at ultra-trace levels by liquid chromatography in reverse mode coupled to positive electrospray ionisation–tandem mass spectrometry. The extraction procedure from environmental solids was optimised by pressurised liquid extraction using acetonitrile:isopropanol (1:1, v/v). The influence of several extraction experimental factors, temperature, pressure, duration and number of cycles, related to the PLE was investigated by an original and efficient chemometric approach. The optimised extraction method (80°C, 40bar, 10min, 1 cycle) exhibited recoveries between 67 and 127% with RSD mostly under 13%. The whole method was applied to real samples: sludge, suspended materials, atmospheric fallouts and roof deposit. Pollutant levels were between 1μgkg−1 and 5.9mgkg−1. [Copyright &y& Elsevier]

Abstract: A broad-based characterisation of a pharmacologically active dichloromethane extract from Isatis tinctoria leaves was carried out. For a comprehensive picture we also included the polar constituents of I. tinctoria (MeOH extract) and for comparative purposes, the taxonomically closely related plant I. indigotica. Diode array detector, evaporative light scattering detector, atmospheric pressure chemical ionisation and electrospray ionisation mass spectrometry, and electrospray ionisation time-of-flight mass spectrometry detectors were used in parallel to ensure a wide coverage of secondary metabolites with highly diverging analytical properties. Off-line microprobe nuclear magnetic resonance spectroscopy after peak purification by semi-preparative high-pressure liquid chromatography served for structure elucidation of some minor constituents. More than 65 compounds belonging to various structural classes such as alkaloids, flavonoids, fatty acids, porphyrins, lignans, carotenoids, glucosinolates and cyclohexenones were unambiguously identified, and tentative structures were proposed for additional compounds. Numerous compounds were identified for the first time in the genus Isatis, and an indolic alkaloid was discovered. [Copyright &y& Elsevier]

Abstract: An automated, confirmatory and sensitive procedure has been developed and validated for the determination of Sudan (I–IV), Sudan Orange G, Sudan Red 7B and Para Red in hot chilli food samples. The proposed method includes pressurised liquid extraction (PLE) with acetone, gel permeation chromatography (GPC) clean-up and detection by liquid chromatography (LC) coupled to electrospray ionization in positive mode tandem mass spectrometry (ESI-MS–MS). The main parameters affecting the performance of the different ionization sources and PLE parameters were previously optimised using statistical design of experiments (DOE). The method was in-house validated on chilli powder and chilli meat. Linear calibrations were obtained with correlation coefficients R 2 >0.999. The limits of detection (LOD) and quantification (LOQ) of the method were in the ranges of 0.002–0.012ngg−1 and 0.006–0.036ngg−1, respectively for chilli powder. The decision limit and detection capability were between 0.005–0.022ngg−1 and 0.007–0.026ngg−1, respectively for chilli meat. Recoveries ranged from 94% to 105%. The applicability of the method to the determination of azo-dyes in hot chilli products was demonstrated. [Copyright &y& Elsevier]

Abstract: We present a new, precise and accurate method for quantitative analysis of chlormequat in soil and aqueous matrices. The method, which is based on LC–MS/MS, pressurised liquid extraction and solid-phase extraction, is eminently suitable for studying the fate of chlormequat in the soil environment. The limit of detection is 0.003–0.008μg/L for rainwater, surface water and groundwater and 0.07–0.4μg/kg for soil. In water samples amended to 0.04μg/L, precision is better than 10%. The residual content of chlormequat in three agricultural topsoils analysed 4 months after its application was 23–55μg/kg (12–23% of the amount applied). No trace of chlormequat was detected in groundwater from 66 water supply wells located in rural areas treated with chlormequat. [Copyright &y& Elsevier]

Abstract: A rapid and simple method is proposed for the routine determination of amoxicillin (AMOX) and penicillin V (PENV) in swine feedingstuffs. The method is based on pressurised liquid extraction (PLE) followed by high performance liquid chromatography with ultraviolet detection (PLE–HPLC–UV) for antibiotic analysis. Parameters affecting PLE procedure, such as temperature, solvent composition, number of extraction cycles and sample cell size, were evaluated in order to achieve the highest extraction efficiency. The optimised method employed 11mL extraction cells, acetonitrile–water mixtures (25:75, v/v) for AMOX and (50:50, v/v) for PENV, as extraction solvent, 102.07atm of extraction pressure, 50°C of extraction temperature, 5min of static time and 60% flush volume of the cell size. Extracts were filtered and directly analysed by HPLC–DAD/UV without further clean-up. Mean recovery rates for feed samples fortified with 200–500mgkg−1 of both antibiotics were 86% for AMOX (RSD≤6%) and 95% for PENV (RSD≤3%). The method was successfully applied to the analysis of a commercial medicated swine feedingstuff, and the results were in good agreement with those obtained using mechanical shaking or ultrasonic extraction combined with solid phase extraction (UE-SPE), previously applied in the literature for feed analysis. The extraction efficiencies were evaluated by statistical comparison (analysis of variance, ANOVA-single factor) of the results obtained using the different extraction methods. Compared to the alternative techniques, PLE offers several practical advantages: easy to perform, fast, savings in solvent volume and in time, all steps are fully automated and further clean-up is not necessary for penicillin analysis. [Copyright &y& Elsevier]

Abstract: Pressurised liquid extraction (PLE) was used to obtain an oleoresin from aromatic turmeric leaves. Four major compounds, which constituted 72% oleoresin, were monitored during the optimisation study. Components in the extract were identified using GC/MS and retention indices. Based on maximum extraction of 1,8-cineole, the optimised operating conditions for PLE, were heating at 147°C, a pressure of 7150kPa and a static time of 17min. The results obtained were compared with conventional isolation procedures, hydrodistillation and Soxhlet extraction, whereby the proposed method was found to be better in term of quantity of the targeted oleoresin compounds, namely, α-phellandrene, p-cymene, 1,8-cineole and terpinolene. [Copyright &y& Elsevier]

Abstract: A comprehensive analytical multi-residue method has been developed for the determination of seven avermectins (abamectin, doramectin, ivermectin, emamectin benzoate, eprinomectin, moxidectin and selamectin) in surface water, sediment and soil samples. Solid samples were extracted applying pressurised liquid extraction followed by a solid-phase extraction (SPE) clean-up step. For aqueous samples, extraction was done utilising only SPE. All compounds were measured using liquid chromatography coupled to tandem mass spectrometry using atmospheric pressure chemical ionisation. The recoveries were 38–67% (relative standard deviation: 9–26%), 63–88% (16–23%) and 63–80% (9–15%) for spiked Rhine water, spiked sediment and spiked soil samples, respectively, and limit of quantifications were 2.5–14ngl−1 in water and 0.5–2.5ngg−1 in soil and sediment. [Copyright &y& Elsevier]

Abstract: Heterocyclic amines (HAs) were analysed in meat extract samples using a new method based on pressurised liquid extraction (PLE) and liquid chromatography–tandem mass spectrometry. This method combines the use of a pressurised fluid with a triple quadrupole MS/MS system, resulting in benefits from both systems: high extraction efficiency and sensitivity. The effects of solvent type and PLE operational parameters, such as temperature and extraction time, were studied to obtain maximum recovery of the analytes with minimum contamination. HA extraction was best achieved using dichloromethane/acetone (50/50, v/v) at 80°C for 10min. Recoveries ranged from 45% to 79% with good quality parameters: limit of detection values between 0.02 and 1ngg−1, linearity (r 2 >0.997), and run-to-run and day-to-day precisions with relative standard deviations lower than 13% achieved at both low (0.20μgg−1) and medium (1.0μgg−1) concentrations. This method reduces sample manipulation and total extraction time by nearly four-fold compared to conventional solid phase extraction. The optimised method was validated using laboratory reference material based on a meat extract, and was successfully applied to HA analysis in several cooked beef samples. [Copyright &y& Elsevier]

Abstract: Separations of eight persistent organohalogenated classes of pollutants, organochlorinated pesticides (OCPs), polychlorinated biphenyls (PCBs), polychlorinated diphenyl ethers (PBDEs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated naphthalenes (PCNs), polychlorinated terphenyls (PCTs) and toxaphene (CTT) by comprehensive two-dimensional gas chromatography (GC×GC) were evaluated. Columns with different polarity and selectivity, including ZB-5, HT-8, DB-17 and BP-10, were selected as first dimension and combined with columns of increasing polarity in the second dimension, i.e. HT-8, BPX-50 and Carbowax (or Supelcowax-10). In total nine column combinations were tested. Because the main interest of the study was fast screening of the test xenobiotic families in complex matrices, in all cases, attention was primarily focussed on group-type separation. Nevertheless, within-group separation was also considered, especially for those classes containing particularly toxic congeners, such as PCBs and PCDD/Fs. Although none of the assayed column sets allowed the simultaneous and complete separation of all pollutants classes, some column combinations provided satisfactory separations among selected families and the rest of pollutants investigated. That was, for instance, the case of HT-8×BPX-50 for PBDEs and PCDD/Fs, DB-17×HT-8 for PCNs and OCPs and BP-10×BPX-50 for CTT, PCDD/Fs and PBDEs. The feasibility of the proposed approach for the fast screening of the target classes of pollutants in complex samples was illustrated by the analysis of food and marine fat samples prepared using simplified miniaturised sample treatment methods. [Copyright &y& Elsevier]

In the present study, pressurised liquid extraction and ultrasound probe sonication, for the latter in combination with a mixed enzymatic treatment in case of rice and straw samples, were applied as sample preparation prior to arsenic speciation analysis by high pressure liquid chromatography coupled to inductively coupled plasma mass spectrometric detection (HPLC-ICP-MS). A significant number of samples as different as rice, straw, soil, nail and hair, all coming from the heavily arsenic-contaminated Middle and Lower Ganga plain area, could be investigated with validated methods, supported by high speed extraction methods. For rice and paddy samples, inorganic arsenic counted up to 70-98% of the total arsenic content, being the major species As (III). The levels of arsenic obtained from straw and soil samples are significantly higher than the background levels, being the major species As (V), thus increasing human exposure to arsenic via the soil-plant-animal-human pathway. Concentrations found in hair and nails were significantly higher than their background levels: 39- and 20-fold for hair and nails, respectively. These samples contained mainly inorganic arsenic in its tri- and pentavalent forms. Results indicate that, under the local frame conditions, arsenic mainly enters into the food chain via its more problematic inorganic forms. Arsenic speciation analysis proves to be a powerful tool for a complete analytical assessment in epidemiological studies covering the endemic areas. [ABSTRACT FROM AUTHOR]

A selective analytical method for the determination of nine organophosphate triesters and triphenylphosphine oxide (TPPO) in outdoor particulate matter is presented. It involves a fully automated pressurised liquid extraction (PLE) step, integrating an alumina clean-up process, and subsequent determination by large-volume injection gas chromatography–positive chemical ionisation–tandem mass spectrometry (LVI-GC–PCI–MS/MS). The extraction variables (solvent, amount of adsorbent, temperature, time and number of cycles) were optimised using a multicriteria strategy which implements a desirability function that maximises both extraction and clean-up efficiencies while searching for the best-compromise PLE conditions. The final method affords quantification limits of between 0.01 and 0.3 μg g−1 and recoveries of >80%, with the exceptions of the most polar analytes, TCEP and TPPO (~65%) for both urban dust and PM10 samples. Moreover, the method permitted the levels of these compounds in dust deposited outdoors (between LOD and 0.5 μg g−1 for TEHP) and PM10 samples (between LOD and 2.4 μg m−3 for TiBP) to be measured and reported for the first time. [ABSTRACT FROM AUTHOR]