Solid-phase Extraction Chromatography Research Articles

Determination of Sedative and Anesthetic Drug Residues in Aquatic Food Products Using Solid Phase Extraction (SPE) and Liquid Chromatography–Tandem Mass Spectrometry (LC–MS/MS)

The residues of sedative and anesthetic drugs in aquatic products are an important factor affecting food safety. In order to screen the residues of sedative and anesthesia drugs in aquatic products, a rapid and sensitive method was established using solid phase extraction (SPE) and high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). The samples were extracted by 80% aqueous acetonitrile by an alumina column and separated by a C18 column. The mass spectra were determined in positive ion mode. The standard curves were matrix matched and quantified by the external standard method. The results showed that the linear ranges of the drugs in aquatic products were from 0.5 to 100 μg kg−1. The correlation coefficient (R 2) was greater than 0.990 and the detection limits were between 0.001 and 0.322 μg kg−1. The average recovery rate and relative standard deviation were between 78.64% and 112.15% and from 0.41%-8.26%. Overall, the developed method showed promising results for the simultaneous qualitative and quantitative determination of the drug residues in aquatic products.

Validation and application of an online extraction and liquid chromatography tandem mass spectrometry assay for the analysis of delamanid and its DM-6705 metabolite in human breast milk

We developed and validated a bioanalytical assay to quantify delamanid and its key metabolite (DM-6705) in breast milk and aimed to quantify the secretion of these compounds in breast milk. Due to the hydrophobic nature of the analytes, special care was taken during sample preparation to prevent the formation of fatty deposits during protein precipitation. This was followed by online solid phase extraction and liquid chromatography with tandem mass spectrometry for detection. A Restek Viva BiPh C18 column (1.0 mm×50 mm, 5 µm) was used for extraction while chromatographic separation was performed using a Waters Xterra MS C18 (2.1 mm×100 mm, 5 μm) analytical column with an isocratic mobile phase consisting of acetonitrile, methanol, and 5 mM ammonium carbonate. The mass spectrometric detection of the analytes was performed using an AB Sciex 3200 mass spectrometer employing electrospray ionisation in the positive mode with multiple reaction motoring of the relevant precursor and product ions. Delamanid-d4 and OPC-14714 were used as internal standards. A quadratic (weighted 1/x concentration) regression was used to fit calibration curves for delamanid and DM-6705 over the concentration range of 10.0 – 1000 ng/mL. The intra- and inter-day validation accuracies of the quality control samples were between 92.1% and 98.3% for delamanid, and 97.0% and 102.8% for DM-6705. The percentage coefficient of variation (precision) was less than 7.8%. To our knowledge, this is the first report describing the concentrations of delamanid and DM-6705 in the breast milk of patients treated for rifampicin-resistant tuberculosis.

Assessment of pheniramine in alternative biological matrices by liquid chromatography tandem mass spectrometry.

Pheniramine is an over-the-counter antihistamine drug. Its accessibility and low cost made it more popular among drug abusers in Pakistan. In this study, pheniramine was quantified in both conventional and alternative specimens of twenty chronic drug abusers, aged 16-50years, who were positive for pheniramine in comprehensive toxicological screening for drugs by gas chromatography with mass spectral detection in positive electron impact mode. Pheniramine was extracted from biological specimens using solid phase extraction and liquid chromatography tandem mass spectrometry was employed for quantification. Chromatographic separation was carried out on a Poroshell120EC-18 (2.1mm × 50mm × 2.7µm) column using water-acetonitrile in formic acid (0.1%) mobile phase in gradient elution mode with 500μL/min flow rate. Positive electrospray ionization mode and multi-reaction monitoring with ion transitionsm/z241.3 → 195.8 and 167.1 for pheniramine andm/zm/z247.6 → 173.1 for pheniramine-d6 were employed. The quantification method showed good linear ranges of 2-1000ng/mL in blood, urine, and oral fluid; 2-1000ng/mg in hair and 5-1000ng/mg in nail with ≥ 0.985% coefficient of linearity. The retention time of pheniramine was 3.0 ± 0.1min. The detection and lower quantification limits were 1ng/mL and 2ng/mL for blood, urine, oral fluid and hair whereas 2.5ng/mg and 5ng/mg for nail, respectively. Mean extraction recovery and ionization suppression ranged 86.3-95.1% and -4.6 to -14.4% in the studied matrices. Intra-day and inter-day precision were 4.1-9.3% and 2.8-11.2%, respectively. Pheniramine levels in specimens of drug abusers were 23-480ng/mL in blood, 72-735ng/mL in urine, 25-379ng/mL in oral fluid, 10-170ng/mg in hair and 8-86ng/mg in nail specimens. Alternative specimens are of utmost significance in clinical and medico-legal cases. In this study, authors compared matrix-matched calibration curves to blood calibration curve and obtained results within ± 10%; thereby justifying the use of blood calibration curve for urine, oral fluid, hair, and nail specimens.

Assessment of legacy and emerging PFAS in the Oder River: Occurrence, distribution, and sources

The purpose of the study was to evaluate the occurrence and distribution of emerging contaminants, poly- and perfluoroalkyl substances (PFAS), in the Polish Oder River, aiming to uncover new insights into their environmental impact. The research aimed to identify potential sources of PFAS, assess water quality levels, and verify compliance with European Union environmental quality standards. The concentrations of 25 PFAS (20 legacy and 5 emerging) in 20 samples from intakes upstream and downstream of urban areas were analyzed using novel, developed in these studies, environmental analytical procedures involving solid phase extraction and liquid chromatography–tandem mass spectrometry. The presence of 14 PFAS was confirmed, and the concentration of Σ14PFAS ranged from 7.6 to 68.0 ng/L. The main components were short-chain analogs. PFBA was the most abundant, accounting for about one-third of all PFAS detected. An exception was observed in the waters of the Gliwice Canal, where ADONA represented half of the detected Σ14PFAS. Alternative PFOS replacements were found in all samples. In 11 of 20 water samples, environmental quality standards for PFOS exceeded the limit of 0.65 ng/L. In 5 of 9 cases, the ability of urban areas to increase PFAS levels in the river was determined. 9.5%–54.4% share of alternative PFAS in relation to the sum of the targeted PFAS showing their increasing use as substitutes for phased-out PFOS. Hierarchical cluster analysis was used to identify potential sources of PFAS. Analysis revealed that PFAS in the Oder River most likely originated from domestic and agricultural wastewater, as well as chemical industry discharges. However, the occurrence of PFAS in the Oder River is low and comparable to other recent European studies. These findings provide valuable insights for environmental management to mitigate the risks associated with PFAS pollution in Polish rivers. Moreover, the developed analytical procedure provides a valuable tool that can be successfully applied by other researchers to monitor PFAS in rivers around the world.

A robust analytical method for simultaneous quantification of 13 low-molecular-weight N-Nitrosamines in various pharmaceuticals based on solid phase extraction and liquid chromatography coupled to high-resolution mass spectrometry

Recently, the potentially highly carcinogenic N-nitrosamines (NAs) have become the focus of pharmaceutical regulatory authorities, the pharmaceutical industry and researchers because trace amounts have been detected in some drug products (DPs), resulting in drug supply shortages. In the absence of sufficient analytical methods for the determination of multiple regulated low-molecular-weight NAs in various DPs, a robust, selective, sensitive and accurate method based on sample preparation by solid phase extraction, followed by liquid chromatography high-resolution mass spectrometry for the simultaneous analysis of 13 regulated low-molecular-weight NAs was developed. The best results for the cleanup were obtained using Strata X-C SPE cartridge. The proposed method was successfully validated according to the USP general chapter 〈1469〉, demonstrating its excellent linearity, accuracy and precision in wide analytical ranges, adjusted to NAs acceptable intake limits. The achieved limits of quantitation correspond to 30 % or less of the acceptable intake limits. The developed analytical method was applied to 16 commercially available DPs containing one to three active pharmaceutical ingredients with different physicochemical properties. Only N-Nitrosodimethylamine was detected in DPs containing ranitidine at levels exceeding the regulatory AI limits by 37.6 - 57.4-fold. In addition, the robustness of the method was confirmed on a considerable number of DPs containing different active ingredients, demonstrating the suitability of the analytical method for routine quality control of different DPs, thus mitigate the risk to human health.

Using Liquid Chromatography-Isotope Ratio Mass Spectrometry for Detection of Economically Motivated Adulteration of Maple Syrup.

Maple syrup is a sought-after commodity, and used as a condiment and a sweetener. Also, it is an active target of economically motivated adulteration (EMA), similar to other foods such as lemon juice and honey. This study is aimed to detect low cost sugar adulteration in maple syrup via an internal standard method using malic acid through solid-phase extraction (SPE) and LC with isotope ratio mass spectrometric detection (LC-IRMS). In this work, an optimized SPE sample preparation procedure was used for the isolation of organic acids from maple syrup. Using LC-IRMS, malic acid was separated from other organic acids and the δ13C value of malic acid was determined. Eleven maple syrup samples, domestic or imported from Canada, were evaluated for 13C/12C ratios (δ13C values) using combustion module-cavity ring down spectrometry (CM-CRDS) and compared to the δ13C values obtained from well-established elemental analyzer-isotope ratio mass spectrometry (EA-IRMS) methods. The δ13C values of isolated malic acid analyzed by SPE-LC-IRMS were used as internal standards and compared to the δ13C values of bulk maple syrup; difference (δ13Csugars - δ13Cmalic acid) values greater than 3.6‰ are indicative of low-cost sugar adulteration. Overall, the results obtained from SPE-LC-IRMS provided a faster, novel analysis approach for determining low-cost sugar adulteration in maple syrup for regulatory purposes. This method also provided lower detectable limits of adulteration versus current literature reports using bulk analysis and comparable detection limits to Tremblay and co-workers who utilized an internal standard method. SPE-LC-IRMS is a robust method that can be used for detecting adulteration in maple syrup samples for regulatory purposes. SPE-LC-IRMS is a faster, novel analysis approach for determining C4 adulteration in maple syrup with lower detection limits.

Rapid and reliable assaying of Tc-99 in sediment samples with novel MTPN polymeric resin

The paper describes a new method for the rapid determination of Technetium (Tc) in sediment samples using solid-phase extraction chromatography (SPEC) with a novel methyl triphenyl phosphoniumnitrate (MTPN) resin. The effectiveness of the resin in selectively recovering Tc was evaluated in both batch and column mode and exploited for rapid analysis of ’Tc’. The procedure involves the acid digestion of samples, pre-concentration of fission products in supernatant and co-precipitation of actinides with Fe(OH)3, followed by selective recovery of Tc by SPEC using a column filled with MTPN resin. The recovered Tc was then radiometrically assayed using beta counting. The method was validated using IAEA certified reference materials and was found to provide reliable and reproducible results for the activity concentration of Tc-99 in sediment samples within 24 h.

Ultra-rapid determination of andrographolide and dehydroandrographolide in Andrographis Herba by solid phase extraction and liquid chromatography with mass spectrometry

AbstractAn ultra-rapid analytical method for determination of andrographolide and dehydroandrographolide in Andrographis Herba (AH) was developed by liquid chromatography with mass spectrometry (LC-MS). The sample was ultrasonically extracted with 10 mL 40% (v/v) methanol, and then purified with a C18 solid phase extraction column. The LC separation was performed on a Poroshell 120 EC-C18 column (30 × 2.1 mm, 2.7 μm) and eluted with 0.5 mmol L−1 ammonium acetate aqueous solution and acetonitrile (65:35) at a flow rate of 0.7 mL min−1, and detected by mass spectrometry (MS). The LC-MS analytical time was less than 1 min. The new developed method presented a good linearity (r > 0.9900), precision and repeatability (RSD < 2.0%). The recoveries for andrographolide and dehydroandrographolide were 93.5% (RSD = 2.2%) and 97.7% (RSD = 2.4%), respectively. The developed method was successfully applied in determination of andrographolide and dehydroandrographolide in seven batches of AH samples, and the contents of analytes in all samples were complied with the relative acceptance criteria in Chinese Pharmacopeia (>0.8%). This new developed LC-MS method is an ultra-rapid assay method for AH, which will help to improve the efficiency and reduce the cost of AH sample test.

Studies of extractable organohalogens in farmed Atlantic salmon muscle and skin by neutron activation in conjunction with size exclusion and solid phase extraction chromatography

Studies of extractable organohalogens in farmed Atlantic salmon muscle and skin by neutron activation in conjunction with size exclusion and solid phase extraction chromatography

Multivariate design and application of novel molecularly imprinted polymers selective for triazole fungicides in juice and water samples

In the present study, novel molecularly imprinted polymers were prepared using penconazole as template and different combinations of functional monomers (acrylic acid (AA) and N-isopropylacrylamide (NIPAM)) and cross-linkers (ethylene glycol dimethacrylate (EGDMA) and trimethylolpropane trimethacrylate (TRIM)), according to a Plackett-Burman design of experiments. Materials were fully characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and nitrogen adsorption analysis. Rebinding behaviors in solution were studied both at the equilibrium (Langmuir, Freundlich and Temkin models), and at the non-equilibrium (pseudo-first, pseudo-second order kinetics). Materials were further tested as sorbents for dispersive solid phase extraction (d-SPE) on apple juice for multicomponent recovery of triazole fungicides at trace level, testing several variations of extraction parameters (juice pH, amount of sorbent, adsorption time, desorption solvent, desorption time) leading to the selection of the best materials and simultaneously of the best extraction conditions. MIPs synthesized with NIPAM showed significatively higher affinity for triazole pesticides in apple juice than the ones synthesized with AA, while no differences emerged for the two cross-linkers employed (EGDMA, TRIM). Selectivity was also assessed, testing MIPs as d-SPE sorbents in undiluted apple juice spiked with triazole pesticides concurrently with other interfering compounds. The newly developed NIPAM-based penconazole-imprinted MIPs showed an excellent recognition mechanism towards compounds containing the triazole ring, and significatively lower recoveries for other compounds. The developed analytical procedure based on molecularly imprinted polymer dispersive solid phase extraction and liquid chromatography coupled with mass spectrometry (MIP-d-SPE-LC-MS) was validated for selective enrichment and determination of triazole compounds in apple juice samples and river water samples with good recoveries (94.67%–109.03% for river water, 89.79%–110.23%, for apple juice), high repeatability (RSD% < 3.97 for river water, RSD% < 4.85 for apple juice), and reproducibility (RSD% < 5.95 for river water and RSD% < 7.14 for apple juice).

Methods optimization and application: Solid phase extraction, ultrasonic extraction and Soxhlet extraction for the determination of antiretroviral drugs in river water, wastewater, sludge, soil and sediment

The continuous release of antiretroviral drugs into the environmental has resulted in the interest to assess their occurrence in various environmental matrices. Their presence has led to antiretroviral drugs being considered the pollutants of concern due to their possible alterations of the ecosystem as well as the antiviral resistance that may develop upon their unintentional consumption. Therefore, in this work, solid phase extraction (SPE), ultrasonic extraction (UE), Soxhlet extration (SE) and liquid chromatography coupled to photodiode array detector (LC-PDA) methods have been optimized and validated. They were then applied for the simultaneous determination of abacavir, nevirapine and efavirenz antiretroviral drugs in wastewater, river water, sludge, soil and sediments. The percentage recoveries ranged from 71% to 112% for SPE, 88 – 108% for SE and 61 – 104% for UE. Good precision with a relative standard deviation less than 20% in all compounds for all methods was obtained. The LODs and LOQs ranged between 0.68 and 0.77 µg/L and 2.1–2.4 µg/L for SPE; 0.8–0.9 µg/kg and 2.3–2.8 µg/kg for SE and 1.6–2.8 µg/kg and 4.9 – 7.0 µg/kg for UE, respectively. The concentrations ranged from <lod - 102 µg/L, <lod – 814 µg/L, and <lod – 6759 µg/L, <lod − 138 µg/g, <lod - 98.9 µg/g, in river water, wastewater, sludge, soil and sediment samples, respectively. Abacavir was dominant in water while efavirenz was dominant in soil/sediments. The results showed that SE is more sensitive and more accurate than UE, hence it can be recommended for routine analysis despite its longer extraction times. The percentage removal efficiency ranged from 44% to 87% for nevirapine, 6–53% for efavirenz, and 75–91% for abacavir which indicates that these compounds were not completely removed during the WWTP processes, hence they ended up in river waters.

Production of Co-58m in a siphon-style liquid target on a medical cyclotron

We present the production of 58mCo on a small, 13 MeV medical cyclotron utilizing a siphon style liquid target system. Different concentrated iron(III)-nitrate solutions of natural isotopic distribution were irradiated at varying initial pressures and subsequently separated by solid phase extraction chromatography. The radio cobalt (58m/gCo and 56Co) was successfully produced with saturation activities of (0.35 ± 0.03) MBq μA−1 for 58mCo with a separation recovery of (75 ± 2) % of cobalt after one separation step utilizing LN-resin.

Steroid hormone levels in postmenopausal hysterectomised women with and without ovarian conservation: the continuous endocrine function of the ovaries

This study aims to clarify the effect of postmenopausal bilateral oophorectomy on plasma steroid hormone levels. Women who were submitted in the postmenopausal period to hysterectomy for uterine benign conditions were divided into two groups: 18 women had isolated hysterectomy and 11 had hysterectomy with bilateral salpingo-oophorectomy. In both groups serum hormone levels were quantified by solid phase extraction and gas chromatography and tandem mass spectrometry. Differences in dehydroepiandrosterone (DHEA), testosterone, androstenedione and oestradiol were determined in both groups. The analysis revealed lower steroid levels in the bilateral salpingo-oophorectomy group when compared to the isolated hysterectomy group with statistically significant differences found for DHEA (5.8 ± 3.2 vs. 9.4 ± 4.4 ng/mL; p = 0.019) and oestradiol (0.69 ± 0.4 vs. 1.48 ± 4.3 ng/mL; p = 0.007). The results are consistent with a significant endocrine activity of the postmenopausal ovary. The clinical consequences of these findings need to be clarified and postmenopausal prophylactic bilateral salpingo-oophorectomy re-evaluated. IMPACT STATEMENT What is already known on this subject? Although it is consensual that premenopausal prophylactic bilateral oophorectomy should not be performed because it has harmful effects on women's health, the evidence regarding the effects of postmenopausal prophylactic bilateral oophorectomy is scarce and this procedure continues to be a regular practice. Few studies have demonstrated that postmenopausal ovaries still have endocrine activity that may impact older women's health. What do the results of this study add? This is the first study to compare hormone levels of postmenopausal women based on their hysterectomy and oophorectomy status using GC-MS/MS, a highly sensitive bioanalytical assay for the measurement of steroid hormones. Previous studies relied on immunoassays and did not compare DHEA levels, which according to the intracrinology theory is a precursor for androgens and oestrogens. In this study, statistically significant lower levels of DHEA and oestradiol were found after postmenopausal bilateral salpingo-oophorectomy. What are the implications of these findings for clinical practice and/or further research? This is a pilot study that may lead to further investigation in this area to clarify the impact of the prophylactic removal of postmenopausal ovaries on older women′s health and lead to changes in surgical procedures.

Impregnation of preparative high‐performance solid phase extraction chromatography columns by organophosphorus acid compounds

The flexible and reversible preparation of columns for use in high-performance solid phase extraction chromatography by physisorption of organophosphorus acid extractants has been investigated in detail. Two extractants have been evaluated, bis (2-ethyl-1-hexyl) phosphoric acid (HDEHP) and 2-ethyl-1-hexyl (2-ethyl-1-hexyl) phosphonic acid (HEHEHP), but the developed procedure should be broadly applicable to other extractants. The liquid-liquid solubility of the extractants in feed solvents consisting of aqueous ethanol solutions of varying composition has been determined. The total amount of adsorbed extractant has been quantified by complete desorption and elution with ethanol followed by acid-base titrimetry. Column impregnation with feed solutions of varying concentration in the undersaturated region has been systematically evaluated, and the influence of a subsequent water wash step has been explored. It is shown that to achieve a robust and reproducible physisorption, the adsorbed amount of extractant should be determined after the wash step, and care must be taken when using indirect methods of measurement. Equilibrium Langmuir-type adsorption isotherms as a function of the extractant concentration in the feed solution have been determined. Adsorption of HEHEHP is higher than HDEHP for equal feed compositions, but the solubility of HEHEHP is lower, resulting in approximately identical maximum coverage levels. The ability of the resulting columns to separate rare earth elements have been verified for a mixture of eight metals using a combined isocratic and gradient elution of nitric acid.

Characterizing the Chemical Contaminants Diversity and Toxic Potential of Untreated Wastewater From a Drug Rehabilitation Hospital: Understanding Impact on Downstream Environment

This study characterizes a total of 21 wastewater samples collected from Al Amal hospital, and aims to determine if untreated hospital wastewater may impose a potentially detrimental impact on the downstream municipal biological wastewater treatment process. By means of solid phase extraction and liquid chromatography with tandem mass spectrometry (LC-MS/MS), chemical contaminants in these wastewater samples were determined in a non-targeted manner. In-silico characterization for the mutagenicity and reactive oxygen species (ROS) producing capabilities was performed by checking against database and literature. However, majority of the chemical contaminants have no prior information available and remain uncharacterized for both traits. Instead, in-vitro mutagenicity tests by means of Ames test showed that majority of the samples were non-mutagenic except for 5 samples that imposed mutagenic effect at high concentrations of &amp;gt;×10. In-vitro tests to determine for intracellular ROS production further showed that one of the mutagenic samples collected on Jun-22 positively induce ROS production and subsequently increased horizontal gene transfer via natural transformation. The findings in this study suggest that a specialty hospital like Al Amal does not frequently contribute mutagenic compounds and ROS to the wastewater streams, and in instances where it contributed positively, would require a high concentration to do so. Hence in general, wastewater streams from a specialty hospital like Al Amal may be unlikely to significantly perturb the downstream environment.

The influence of aeration rate on the sorption of emerging pharmaceuticals in activated sludge

ABSTRACT The sorption of pharmaceuticals on activated sludge during the wastewater treatment process has been widely studied and considered one of the main mechanisms for the removal of these micropollutants from domestic sewage. Understanding the removal mechanism is important to reduce the environmental risk associated with these compounds. To the best of our knowledge, no data are reporting the influence of the aeration rate and, consequently, of the physicochemical properties of the sludge flocs, on the sorption of pharmaceutical compounds. In this context, the influence of the aeration rate (2, 5, and 8 L min−1) on the physical properties of the sludge and the sorption of two emerging pharmaceuticals, 17-alpha-ethynylestradiol (EE2) and diclofenac (DCF), was evaluated. The pharmaceuticals were analyzed by Solid Phase Extraction and Liquid Chromatography, and the sludge by Laser Particle Size Analyzer and Settling Curves. As a result, higher sorption for 17-alpha-ethinylestradiol (78-96%) in comparison to diclofenac (23-43%) was observed, corroborating the greater hydrophobicity of EE2. Higher pharmaceuticals removal rates were observed for the highest aeration (10.02 µgEE2 gSST−1 and 3.99 µgDCF gSST−1) in comparison to the lowest one (7.81 µgEE2 gSST−1 and 2.58 µgDCF gSST−1), what can be attributed to structural and surface changes in flocs. Smaller and more dispersed flocs were observed when aeration was increased (104.4 µm for 8 L min−1 and 63.8 µm for 2 L min−1). The results suggest that the increase in aeration seems to be promising for the removal of pharmaceuticals by sorption in sewage sludge, especially for the hydrophobic ones.

Exploiting Flow-Based Separation Techniques for Sample Handling in Wine Analysis

Wine is a fermented product consumed in a large scale all over the world that therefore has a large impact both economic and food safety terms. The analytical control of the final product is thus of high importance; it is not a simple task given that the chemical composition of wine is very variable and complex. Consequently, there is always the need for some sample pre-treatment prior to analysis. Flow-based analyses are known for their efficiency in sample manipulation and can be easily coupled to other techniques, such as separation techniques, namely membrane-based or extraction procedures. This possibility is an important step when dealing with complex matrices, such as wine samples. This review presents the state of the art of the methodologies that were developed using flow-based systems coupled to separation devices applied to wine analysis, namely membrane-based, solid, and liquid phase extraction and low pressure chromatography separations.

Biomonitoring of glyphosate and AMPA in the urine of Spanish lactating mothers

The objectives of this study were to evaluate the urinary levels of Glyphosate (Gly) and its metabolite aminomethylphosphonic acid (AMPA) in Spanish breastfeeding mothers (n = 97), to identify the main predictors of exposure and to perform a risk assessment.Urine samples were analyzed using a method based on solid phase extraction and liquid chromatography tandem mass spectrometry (LC-MS/MS) determination. The developed method showed limits of quantification of 0.1 μg/L for both analytes. The detection frequencies (DFs) were 54% for Gly and 60% for AMPA, with geometric means (GMs) of 0.12 μg/L and 0.14 μg/L, respectively. In the statistical analysis, no relationship was found between the urinary levels of Gly and AMPA. Multiple regression analysis showed a significant relationship between the intake of eggs and fruits and Gly levels in urine. Estimated daily intakes (EDIs), hazard quotients (HQs), and a hazard index (HI) were calculated to analyze the obtained data from a health risk perspective. The GMs of the EDIs were 0.31 and 0.37 μg/kg of body weight (BW)/day for Gly and AMPA, respectively. The HQs were calculated considering 0.5 mg/kg BW/day as an acceptable daily intake (ADI), which EFSA has established as a health-based reference value for both analytes. The values obtained were lower than 1, and thus, low health risk due to Gly and AMPA exposure was expected for the population under study.

Automation in quantifying phenoxy herbicides and bentazon in surface water and groundwater using novel solid phase extraction and liquid chromatography tandem mass spectrometry

The occurrence of phenoxy herbicides is a financial and regulatory concern for drinking water treatment plants. This paper presents a new method of quantification for nine phenoxy-acids and bentazon in different water samples using liquid chromatography tandem mass spectrometry (LC-MS/MS). The method is based on an automated solid phase extraction (SPE) process that applied hydrophilic modified polystyrene and divinylbenzene cartridges at low pH (<2.0). Main advantages of the presented method include the reduced consumption of organic solvent in extraction and the fully automated sample pre-concentration. The method is thus more environmentally-friendly. In the quantification step, five stable isotopically labelled analogues were used as internal standards to account for the losses during sample preparation and to calibrate the ion source response under the mass spectrometric detection. The method was optimized in terms of sample preparation and subsequent LC-MS/MS separation to obtain reliable measurement of the analyte concentration during real sample analysis. The method quantification limit was between 1.5 and 10.0 ng/L for target compounds in surface water and groundwater samples. The method was validated at three fortification levels between 10.0 and 1000 ng/L, and the results showed fit-for-purpose recovery with appropriate precision at low concentration levels. The method was also utilized to analyse thirty-two actual water samples from different sources. Forty percent of the analysed samples contained detectable level of herbicides, ranging from 1.91 to 40.5 ng/L. The concentrations of targeted herbicides in our study were comparable to those found in water samples in other regions of world.

Assessment of Human Pharmaceuticals in Drinking Water Catchments, Tap and Drinking Fountain Waters

The occurrence of pharmaceuticals in water catchments and drinking waters raises potential risks to public health. Therefore, after addressing the major aquatic contamination pathway, the wastewater treatment plants (WWTPs), and, subsequently, surface waters, 18 human pharmaceuticals from 6 therapeutic groups (antibiotics, lipid regulators, selective serotonin reuptake inhibitors, non-steroidal anti-inflammatory drugs (NSAIDs) and hormones) were analyzed in drinking water catchments, tap and drinking fountain waters. This was performed by solid phase extraction (SPE) and liquid chromatography coupled with tandem mass detection (LC-MS/MS). The 97 samples analyzed were collected from 31 different sites in the center of Portugal. All samples presented concentrations below the method detection limits (MDLs) that ranged between 1.13 to 5.45 ng L−1. The achieved results contributed to a better knowledge on the Portuguese and European context of drinking water, since there is a knowledge gap regarding this matrix. Comparing our data with other studies, published worldwide, we can observe that median concentrations of pharmaceuticals were reported in the low ng L−1 levels, values close to our MDLs. Consequently, it is unlikely that, in light of the current knowledge, the presence of pharmaceuticals in drinking water presents a threat to human health.