Concentrations and temporal trends in pesticide biomarkers in urine of Swedish adolescents, 2000-2017.

Agricultural pesticides are extensively used for weed- and pest control, resulting in residues of these compounds in food. The general population is mainly exposed through dietary intake. Exposure to certain pesticides has been associated with adverse human health outcomes. Our aim was to assess urinary concentrations and temporal trends in the biomarkers of commonly used pesticides. Samples were collected from adolescents (n = 1060) in Scania, Sweden, from 2000 to 2017. Concentrations of 14 pesticide biomarkers were analyzed in urine using LC-MS/MS. Temporal trends in biomarker concentrations (ln-transformed) were evaluated using linear regression. Biomarkers of pyrethroids (3-PBA and DCCA), chlorpyrifos (TCPy), chlormequat (CCC), thiabendazole (OH-TBZ), and mancozeb (ETU) were detected in >90% of the population all sampling years. The biomarkers CCC and TCPy had the highest median concentrations (>0.8 µg/L), whereas the biomarkers of cyfluthrin (4F-3-PBA) and two pyrethroids (CFCA) had the lowest median concentrations (<0.02 µg/L). Increasing temporal trends were found for the biomarkers 3-PBA (3.7%/year), TCPy (1.7%/year) and biomarkers of pyrimethanil (11.9%/year) and tebuconazole (12.2%/year). Decreasing trends were found for CCC (-5.5%/year), OH-TBZ (-5.5%/year), and ETU (-3.9%/year). Our results suggest that Swedish adolescents are commonly exposed to pesticides in low concentrations (median concentrations <3.88 µg/L).

Biomarkers of Exposure to Pyrimethanil After Controlled Human Experiments.

Pyrimethanil (PYM) is a fungicide used pre- and post-harvest on many crops. It has a low acute toxicity but is of toxicological concern because of its antiandrogenic properties. The aim of the current work was to investigate some metabolism and estimate elimination kinetics of PYM in humans after experimental oral and dermal exposure. A liquid chromatography triple quadrupole mass spectrometry (LC-MS-MS) method was developed and validated for the analysis of PYM and its metabolite 4-hydroxypyrimethanil (OH-PYM) in human urine. The method was applied to analyze urine obtained from two volunteers experimentally exposed to PYM. The elimination of OH-PYM seemed to follow first-order kinetics and a two-phase excretion. After the oral exposure, the elimination half-life of OH-PYM in the rapid phase was 5 and 3 h for the female and male volunteer, respectively. In the slower phase, it was 15 h in both volunteers. After the dermal exposure, the half-life in the rapid phase was 8 h in both volunteers. In the slower phase, it was 30 and 20 h, respectively. About 80% of the oral dose was recovered as urinary OH-PYM in both volunteers. The dermal dose recovered as urinary OH-PYM was 9.4% and 19%, in the female and male volunteer, respectively. OH-PYM was mainly found as a conjugate of sulfonate and glucuronic acid. No free PYM was found. The analytical method showed good within-run, between-run and between-batch precision with a coefficient of variation between 6% and 12%. A limit of detection of 0.1 ng/mL and a limit of quantification of 0.4 ng/mL were achieved for both the analytes. The method was applied to biomonitor PYM exposure in populations in Sweden. OH-PYM was detected in nearly 50% and 96% of samples from the environmentally and occupationally exposed populations, respectively.

Determination of 4'-isobutylacetophenone and other transformation products of anti-inflammatory drugs in water and sludge from five wastewater treatment plants in Sweden by hollow fiber liquid phase microextraction and gas chromatography-mass spectrometry.

This work describes the development of a two-phase hollow fiber liquid phase microextraction method for the determination of three hydrophobic transformation products of the nonsteroidal anti-inflammatory drugs ketoprofen, ibuprofen and diclofenac: 3-acetobenzophenone, 4´-isobutylacetophenone and diclofenac amide. The optimized method involved extraction for 180 min at a stirring speed of 440 rpm. Hollow fibers (0.6mm i.d.) of 6 cm length were employed and the acceptor phase consisted of 1-octanol. 5% Sodium chloride was added to samples to prevent loss of the solvent during extraction. Extracts were analyzed by GC-MS and method detection limits were in the range of 1.6-5.6 ng L(-1). The method was applied for the determination of target analytes in influent samples from five Swedish wastewater treatment plants (WWTPs). All three analytes were found in very low or non-detectable concentrations. The most abundant compound was 3-acetobenzophenone found at four of the investigated WWTPs at an average concentration of 62 ng L(-1). Diclofenac amide and 4'-isobutylacetophenone were only detected above LOD at one WWTP each at a concentration of 55 and 197 ng L(-1), respectively. Samples of water entering and exiting the activated sludge treatment as well as digested sludge were also collected from one of the WWTPs. Only diclofenac amide was detected in these samples. A higher concentration was detected in the effluent from the activated sludge treatment than the influent, thus indicating the formation of this compound during treatment. In the sludge, diclofenac amide was detected at 183 ng g(-1)wet weight. Based on these results it can be concluded that the amounts of these compounds reaching WWTPs are very small, suggesting negligible risks to the aquatic environment. However, they also indicate the potential formation during the activated sludge process and accumulation into sludge for at least one of the compounds which is why further studies of these processes are needed.

Behaviour of nonsteroidal anti-inflammatory drugs and eight of their metabolites during wastewater treatment studied by hollow fibre liquid phase microextraction and liquid chromatography mass spectrometry.

In this work hollow fibre liquid phase microextraction combined with liquid chromatography mass spectrometry was applied for the determination of the nonsteroidal anti-inflammatory drugs (NSAIDs) ketoprofen, naproxen, diclofenac and ibuprofen as well as eight of their known human metabolites in wastewater samples. Extraction time and addition of tri-n-octylphosphine oxide (TOPO) to the liquid membrane were evaluated resulting in a method with an optimal extraction time of 5h and 5% (w/V) TOPO addition to the membrane liquid (di-n-hexyl ether). With the optimized method, enrichment factors ranged between 778 and 4830. The method was applied for analysis of samples collected from Källby wastewater treatment plant in the city of Lund, Sweden. Samples were collected from the influent, water entering as well as exiting the conventional activated sludge treatment and the effluent to study the behaviour of these compounds during the treatment process. All twelve substances were found in the influent and for all four drugs, higher concentrations were detected of the metabolites than the parent compounds. Highest concentrations were detected of o-desmethylnaproxen, 2-hydroxyibuprofen and carboxyibuprofen (average influent concentrations of 45, 35 and 63 µg/L respectively). The study showed only partial removal during the primary treatment whereas both parent compounds and metabolites were efficiently removed during the activated sludge process. In the effluent all analytes were detected in concentrations below 1 µg/L thus showing that either the investigated metabolites do not belong to the NSAID transformation products formed during the activated sludge treatment or they are also quickly further transformed within the treatment.

Study of the uptake of non-steroid anti-inflammatory drugs in wheat and soybean after application of sewage sludge as a fertilizer.

Non-steroid anti-inflammatory drugs (NSAIDs) are frequently occurring in sludge and waters from sewage treatment plants (STPs). Sludge obtained from sewage treatment is often applied as a fertilizer in agriculture and not many studies about the uptake of pharmaceuticals into crops can be found. In this paper, we present a greenhouse experiment to study the presence of four NSAIDs (naproxen, ketoprofen, diclofenac and ibuprofen) in two different crops (soybean and wheat) after application of sludge as a fertilizer. Two different amounts of sludge were added to the soil; the recommended amount (with respect to phosphorus content) and the double recommended amount. One treatment without sludge was also included as a blank. The crops were harvested after 60 as well as 110 days. Only diclofenac and ibuprofen were detected in the sludge in concentrations of 22 and 217 ng g(-1) dry weight, respectively. None of the NSAIDs were detected in the crops from any of the treatments. Compared to the amounts applied to the soil, detection limits correspond to an uptake of less than 2% for diclofenac and 0.8% for ibuprofen.

Comparison of two extraction methods for the determination of selective serotonin reuptake inhibitors in sewage sludge by hollow fiber liquid-phase microextraction.

This paper presents two procedures for the determination of four selective serotonin reuptake inhibitors (citalopram, paroxetine, fluoxetine, and sertraline) and one metabolite (norfluoxetine) in sewage sludge utilizing three-phase hollow fiber liquid-phase microextraction (HF-LPME). First, direct HF-LPME was used for extraction, clean-up, and preconcentration. The pharmaceuticals were extracted from slurry samples into an organic phase and then back-extracted into an aqueous phase in the lumen of the hollow fiber. Second, a procedure combining pressurized hot water extraction and HF-LPME for clean-up and preconcentration was developed for the same analytes and matrix. The extracts were subsequently analyzed by liquid chromatography-mass spectrometry. For direct HF-LPME, limits of detection were between 1 and 12 ng g(-1) (dry weight) and the relative standard deviation (RSD) values were 3-12%. For the second method, limits of detection were approximately 6 ng g(-1) for all the compounds and RSD values were 8-12%. The methods were validated by comparison of results for the same samples. Sewage sludge from a Swedish wastewater treatment plant was analyzed by both methods; average concentrations were similar for citalopram, paroxetine, and fluoxetine with values of approximately 530, 40, and 200 ng g(-1) , respectively.

Hollow fiber liquid phase microextraction as a preconcentration and clean-up step after pressurized hot water extraction for the determination of non-steroidal anti-inflammatory drugs in sewage sludge.

A method for the quantitative determination of non-steroidal anti-inflammatory drugs (NSAIDs) in sewage sludge was developed and validated. The target compounds were extracted using pressurized hot water extraction (PHWE) and then purified and preconcentrated by three-phase hollow fiber liquid phase microextraction (HF-LPME) followed by LC-ESI-MS analysis. The PHWE was optimized with regard to the pH of solvent as well as other operational parameters. The optimum conditions were 0.01 M NaOH as the extraction solvent, temperature of 120 °C, pressure of 100 bar, static time 5 min, 5 cycles, flush volume 90% and purge time 60s. Spike recoveries for sludge samples spiked at 200 ng g⁻¹ were in the range of 101-109% but for the native drugs in non-spiked sludge samples, recoveries were 38.9%, 59.8%, 90.3% and 47.8% for ketoprofen, naproxen, diclofenac and ibuprofen, respectively. Donor phase pH, ionic strength and extraction time were optimized for HF-LPME after PHWE. The optimum conditions were 2h extraction at pH 1.5 without salt addition. Enrichment factors in the range of 947-1213 times were achieved (extraction recoveries were 23.6-30.3%) for HF-LPME after PHWE. The matrix effect on the ionization of drugs in LC-ESI-MS was also investigated. The results show that there is a smaller matrix effect (-8.9% to +14.6%) in comparison with other published values obtained using solid phase extraction (SPE) for clean-up after pressurized liquid extraction (PLE). Method detection limits (MDLs) and method quantification limits (MQLs) for different drugs were in the range of 0.4-3.7 ng g⁻¹ and 1.5-12.2 ng g⁻¹ in dried sludge samples, respectively. The characteristics of the proposed method were compared with those of other published works. The considerably lower ion suppression/enhancement and minimum use of organic solvents (a few microliters of di-n-hexyl ether) in the sample preparation step are two highlighted advantages of the proposed method in comparison with previously published works. The method was applied to determine NSAIDs in sewage sludge from Källby wastewater treatment plant (Lund, Sweden) in April, June, August and October 2010. The highest concentration level was recorded for ibuprofen in the April sewage sludge sample (588 ng g⁻¹) and all of the selected NSAIDs were detected in all the samples analyzed.

Determination of non-steroidal anti-inflammatory drugs in sewage sludge by direct hollow fiber supported liquid membrane extraction and liquid chromatography-mass spectrometry.

In this study, a three-phase hollow fiber liquid-phase microextraction (HF-LPME) method combined with liquid chromatography-mass spectrometry was developed for direct determination of four non-steroidal anti-inflammatory drugs (ketoprofen, naproxen, diclofenac and ibuprofen) in sewage sludge. The drugs were extracted from non-spiked and spiked slurry samples with different amounts of sludge into an organic phase and then back-extracted into an aqueous phase held in the lumen of the hollow fiber. High enrichment factors ranging from 2761 to 3254 in pure water were achieved. In sludge samples, repeatability and inter-day precision were tested with relative standard deviation values between 10-18% and 7-15%, respectively. Average concentrations of 29±9, 138±2, 39±5 and 122±7 ng/g were determined in dried sludge from Källby sewage treatment plant (Sweden) for ketoprofen, naproxen, diclofenac and ibuprofen, respectively.