Reclamation of agro-wastewater polluted with thirteen pesticides by solar photocatalysis to reuse in irrigation of greenhouse lettuce grown.

In Mediterranean countries, reuse of reclaimed water is essential for crop irrigation. The occurrence of pesticides in agro-wastewater may represent a risk for human health and environment owing to their release in soil and translocation to plants. The novelty of this work relies on the reuse of reclaimed agro-wastewater polluted with thirteen pesticides for lettuce irrigation. Removing of pesticide residues in agro-wastewater was carried out using natural sunlight and TiO2/Na2S2O8 in a pilot facility located in Murcia (SE of Spain). The studied pesticides were azoxystrobin, boscalid, chlorpropham, flutolanil, flutriafol, isoxaben, methoxyfenozide, myclobutanil, napropamide, prochloraz, propamocarb, propyzamide and triadimenol, which are commonly used in southeast Spain to treat lettuces grown. Different heterogeneous and homogeneous processes were studied and compared. Previously, the optimization of the process for the selection of the best catalytic system was performed at lab-scale. TiO2+ S2O82- was selected due to the greater effectiveness, achieving almost complete disappearance after about 400 kJ m-2 of cumulative UVA exposure. No significant differences were observed in quality parameters of lettuce grown using treated and non-treated agro-wastewater.

Solar reclamation of agro-wastewater polluted with eight pesticides by heterogeneous photocatalysis using a modular facility. A case study.

In this work, we have studied the removal of eight pesticides, commonly used in fruit crops, in agro-wastewater generated in commercial farms by the cleaning of trace of phytosanitary products in containers and tanks from treatment equipment. The studied pesticides were acetamiprid, cyproconazole, cyprodinil, difenoconazole, fenhexamid, hexythiazox, myclobutanil and thiamethoxam. The trials were performed in a pilot facility located in Murcia (SE of Spain), using natural sunlight and titanium dioxide (TiO2) in tandem with Na2S2O8. Five photocatalytic treatments were carried out during autumn 2017. Results show that the mean (n = 5) final amount was about 13% of the initial pesticide mass present in agro-wastewater. Therefore, we have proved that this technology could be used for tackling the elimination of pesticide residues in agro-wastewater and has favourable prospects of being applied in the water treatment sector.

Prevalence of acute poisoning treated in 3 hospitals in Southeast Spain. / Prevalencia de las intoxicaciones agudas asistidas en 3 hospitales del sureste español.

OBJECTIVE: To assess the characteristics of acute poisoning cases treated in hospital emergency departments over 5 years. METHODS: Retrospective study of acute poisoning cases treated in 3 hospitals between 2013 and 2017 and an analysis of the demographic characteristics, types of poisoning, seasonal variations, care received and recurrence. RESULTS: Some 0.51% of all cases treated in the 3 hospitals corresponded to acute poisoning. The percentages varied by hospital location (0.91% urban, 0.37% coastal and 0.22% rural). Cases of alcohol poisoning had a seasonal character, increasing during the summer on the coast (P<.05). There were differences in the type of poisoning ( P<.05) for patients 31 years of age and older in the 3 hospitals. Alcohol represented the largest number of cases in patients 31 years of age and older, except in the rural area where most cases were due to voluntary poisoning in attempted suicide. Men had a higher prevalence of poisoning than women (55.77% vs. 44.23%) for all cases. Alcohol poisoning was in first place for men 30-75 years, and voluntary poisoning for attempted suicide was first for women, except for those 30-46 years of age for whom alcohol was also number one. The large number of cases of recurrence were due to alcohol in men (791 cases) and to benzodiazepines in women (528 cases). CONCLUSIONS: The number of cases and the type of poisoning varied according to hospital location, season, patient sex and patient age.

Description of a new anaerobic thermophilic bacterium, Thermoanaerobacterium butyriciformans sp. nov.

Strain USBA-019T, an anaerobic and thermophilic strain, was identified as a new member of the genus Thermoanaerobacterium. USBA-019T cells are gram-positive, strictly anaerobic, thermophilic, chemoorganotrophic, moderately acidophilic, non-motile, endospore-forming, slightly curved, and rod-shaped. Cells measure 0.4×3.0-7.0µm. Optimal growth occurs at 50-55°C (35-65°C). Optimum pH is 5.0-5.5 (4.0-8.5). Thiosulfate, elemental sulfur and nitrate were utilized as electron acceptors. Fermentation of glucose, lactose, cellobiose, galactose, arabinose, xylose, starch and xylan primarily produced acetate and butyrate. Xylan, starch and cellobiose produced ethanol and starch, cellobiose, galactose, arabinose and mannose produced lactic acid. Phylogenetic analyses based on 16S rRNA gene sequence comparison and genomic relatedness indices show the close relation of USBA-019T to Thermoanaerobacterium thermostercoris and Thermoanaerobacterium aotearoense (similarity value: 99%). Hybridization of USBA-019T, Th. thermostercoris DSM22141T and Th. aotearoense DMS10170T found DNA-DNA relatedness of 33.2% and 18.2%, respectively. Based on phenotypic, chemotaxonomic and phylogenetic evidence, along with low identity at whole genome level, USBA-019T is a novel species of the genus Thermoanaerobacterium which we propose to name Thermoanaerobacterium butyriciformans sp. nov. The type strain is USBA-019T (=CMPUJ U-019T=DSM 101588T).

Abatement of spinosad and indoxacarb residues in pure water by photocatalytic treatment using binary and ternary oxides of Zn and Ti.

The photodegradation of indoxacarb, a broad spectrum foliar insecticide and spinosad, a natural insecticide containing two active ingredients, spinosyn A (major component) and spinosyn D (minor component), was studied in aqueous suspensions of binary (ZnO and TiO2) and ternary (Zn2TiO4 and ZnTiO3) oxides under artificial light (300-460 nm) irradiation. As expected, the influence of the semiconductor materials on the degradation of both was very significant in all cases. Photocatalytic experiments showed that the addition of semiconductors in tandem with Na2S2O8 as electron acceptor strongly improved the removal of indoxacarb and spinosad in water compared with the photolytic tests. The reaction rates significantly increased, especially for the ZnO/Na2S2O8 and TiO2/Na2S2O8 systems. The first-order equation (monophasic model) satisfactorily explained the disappearance process, although it offered no explanation for the small concentrations remaining in the process.

Use of farming and agro-industrial wastes as versatile barriers in reducing pesticide leaching through soil columns.

Increased interest has been recently focused on assessing the influence of the addition of organic wastes related to movement of pesticides in soils of low organic matter (OM) content. This study reports the effect of two different amendments, animal manure (composted sheep manure) and agro-industrial waste (spent coffee grounds) on the mobility of 10 pesticides commonly used for pepper protection on a clay-loam soil (OM = 0.22%). The tested compounds were azoxystrobin, cyprodinil, fludioxonil, hexaconazole, kresoxim-methyl, pyrimethanil, tebuconazole, and triadimenol (fungicides), pirimicarb (insecticide), and propyzamide (herbicide). Breakthrough curves were obtained from disturbed soil columns. Cumulative curves obtained from unamended soil show a leaching of all pesticides although in different proportions (12-65% of the total mass of compound applied), showing triadimenol and pirimicarb the higher leachability. Significant correlation (r = 0.93, p<0.01) was found between the observed and bibliographical values of GUS index. The addition of the amendments used drastically reduced the movement of the studied pesticides. Only two pesticides were found in leachates from amended soils, pyrimethanil (<1%) for both, and pirimicarb (44%) in the soil amended with spent coffee grounds. A decrease in pesticide leaching was observed with the increase in dissolved organic matter (DOM) of leachates. The results obtained point to the interest in the use of organic wastes in reducing the pollution of groundwater by pesticide drainage.

Photocatalytic degradation of eight pesticides in leaching water by use of ZnO under natural sunlight.

Photodegradation of eight pesticides in leaching water at pilot plant scale using the tandem ZnO/Na(2)S(2)O(8) as photosensitizer/oxidant and compound parabolic collectors under natural sunlight is reported. The pesticides, habitually used on pepper culture and belonging to different chemical groups were azoxyxtrobin, kresoxim-methyl, hexaconazole, tebuconazole, triadimenol, and pyrimethanil (fungicides), primicarb (insecticide), and propyzamide (herbicide). As expected, the influence of the semiconductor used at 150 mg L(-1) on the degradation of pesticides was very significant in all cases. Photocatalytic experiments show that the addition of photosensitizer strongly improves the elimination of pesticides in comparison with photolytic tests; significantly increasing the reaction rates. The use of Na(2)S(2)O(8) implies a significant reduction in treatment time showing a quicker reaction time than ZnO alone. On the contrary, the addition of H(2)O(2) into illuminated ZnO suspensions does not improve the rate of photooxidation. The disappearance of the pesticides followed first-order kinetics according to Langmuir-Hinshelwood model and complete degradation occurs from 60 to 120 min. The disappearance time (DT(75)), referred to the normalized illumination time (t(30 W)) was lower than 3 min in all cases.

Decline of pesticide residues from barley to malt.

The fate of dinitroaniline herbicides (pendimethalin and trifluralin), organophosphous insecticides (fenitrothion and malathion), and pyrimidine (nuarimol) and triazole (myclobutanil and propiconazole) fungicides from barley to malt was determined. Several samples for residue analysis were taken after each stage of malting (steeping, germination and kilning). Pesticide residue analysis was carried out by GC/ITMS in selected ion monitoring mode. Pesticides decline along the process, although in different proportions. The carryover of residues after steeping was 45-85%. A good correlation (r > 0.92) was observed between percentages removed after steeping and the P(OW) values of pesticides. The amount remaining after malting ranged from 13 to 51% for fenitrothion and nuarimol, respectively. Steeping was the most important stage in the removal of pesticide residues (52%) followed by germination (25%), and kilning (drying and curing, 23%). During malt storage (3 months) the fall in pesticide residues was not significant. Applying the standard first-order kinetics equation (r > 0.95), the half-lives obtained for the pesticides during malt storage varied from 244 to 1533 days for myclobutanil and nuarimol, respectively.

Arsenic extraction and speciation in carrots using accelerated solvent extraction, liquid chromatography and plasma mass spectrometry.

Arsenic present in freeze-dried carrots was extracted using accelerated solvent extraction (ASE). Several parameters, including selection of the dispersing agent, extraction time, number of extraction cycles, particle size and extraction temperature, were evaluated to optimize the ASE method. Filtering and treatment with C-18 SPE cartridges were also evaluated as part of the sample preparation procedure before speciation analysis. The method was validated by spiking single arsenical and mixed arsenical standards on the dispersing agent and on portions of freeze-dried carrot prior to extraction. LC-ICP-MS was used to determine individual arsenic species in the carrot extracts. A weak anion-exchange column was used for the separation of As(III), As(v), monomethylarsonic acid (MMA), dimethylarsinic acid and arsenobetaine. Optimized sample preparation conditions were applied to the extraction of arsenic in nine freeze-dried carrot samples. Total arsenic concentration in the carrot samples ranged from less than 20 ng g(-1) to 18.7 microg g(-1), dry mass. Extraction efficiency, defined as the ratio of the sum of individual arsenic species concentrations to total arsenic, ranged from 80 to 102% for freeze-dried carrots with arsenic concentrations greater than the limit of quantitation. Inorganic As(III) and As(v) were the only species found in samples that contained less than 400 ng g(-1) total arsenic. MMA and an unidentified arsenic compound were present in some of the samples with higher total arsenic content.

Multiresidue method for the rapid determination of organophosphorus insecticides in grapes, must and wine.

A rapid multiresidue gas chromatographic method for determining 12 insecticides in grapes, must and wine is described. A simple on-line microextraction method for isolating frequently applied insecticides on vineyard is used. The matrix, once extracted with an acetone-dichloromethane (1:1, v/v) mixture, was filtered and concentrated. Nitrogen-phosphorus detection (NPD) and electron-capture detection (ECD) were used to identify and quantify the insecticides, the findings being confirmed using mass spectrometric detection (MSD). No clean-up was necessary for either NPD or ECD. The regression coefficients relating to linearity were at least 0.99. Recoveries from spiked grape, must and wine samples ranged from 80 to 108% and relative standard deviations were no higher than 16% in the most unfavourable case. Individual detection limits were in the range 0.02-0.1 ng. Limits of quantification varied from 0.01 to 0.05 mg kg(-1), which are below the maximum residue limits set by the legislation of the main wine-producing countries of the European Union. Only in the case of methidathion and quinalphos were the limits of quantification equivalent to the maximum residue limits (0.05 mg kg(-1)) established by Spanish and French legislation, respectively.

Multiresidue method for the rapid determination--in grape, must and wine--of fungicides frequently used on vineyards.

A rapid multiresidue gas chromatographic method for determining 17 fungicides in grapes, must and wine, widely used on vineyards, is described. A simple on-line microextraction method for isolation of fungicides was used. Nitrogen-phosphorus and electron-capture detection were used for the identification and quantitation of pesticides. For confirmation, mass spectrometic detection was used. Because of the high selectivity of both detection methods, no clean-up was necessary. The regression coefficients relating to linearity were at least 0.994. Recoveries from spiked grapes, must and wine samples ranged from 78 to 107% and relative standard deviations were not higher than 14%. Individual detection limits were in the range 0.02-0.1 ng. Limits of quantification varied from 0.01 to 0.05 mg/kg, smaller in all cases than the maximum residue limits set down by the legislations of Spain, France and Italy, the main wine-producing countries of the European Union. Only for fludioxonil and hexaconazole do the limits of quantification coincide with the maximum residue limits (0.05 mg/kg) established by the Spanish legislation.

Element selective detection for supercritical-fluid chromatography.

This manuscript describes the use of Supercritical-Fluid Chromatography (SFC) with plasma spectrometric detection for the analysis of organometallics. An introduction on the principles and characteristics of Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) is included, along with a discussion about requirements for coupling SFC to plasma detection and the different approaches for interfacing SFC to ICP. The last part of this review paper provides a comprehensive description of SFC-ICP applications for the analysis of organometallics containing iron, silicon, tin, chromium, arsenic, lead, mercury and antimony.

Multi-element detection of organometals by supercritical fluid chromatography with inductively coupled plasma mass spectrometric detection.

Organometal compounds of arsenic, antimony, and mercury are speciated using supercritical fluid chromatography with inductively coupled plasma mass spectrometric (ICP-MS) detection. The multi-element capability of ICP-MS for transient signals is examined by detecting five compounds containing all three elements in a single chromatographic injection. The results obtained are compared with those obtained from flame-ionization detection (FID). Trimethyl arsine is not distinguished from the solvent peak when FID is used because it coelutes with the solvent, whereas trimethyl arsine is detected when ICP-MS is used because of its element-selective nature. The detection limits obtained by ICP-MS are 2-3 orders of magnitude lower than those obtained by FID. Determination of isotope abundance is also demonstrated for triphenyl antimony and diphenyl mercury compounds.

Chromium speciation by anion-exchange high-performance liquid chromatography with both inductively coupled plasma atomic emission spectroscopic and inductively coupled plasma mass spectrometric detection.

Development of a new method for the determination of Cr(III) and Cr(VI) is described. Anion-exchange high-performance liquid chromatography (HPLC) was used to separate Cr(III) and Cr(VI) with on-line detection by inductively coupled plasma atomic emission spectroscopy (ICP-AES) at 2766 A in preliminary studies, and inductively coupled plasma mass spectrometry (ICP-MS) with single-ion monitoring at m/z 52 and m/z 53 for final work. A mobile phase consisting of ammonium sulfate and ammonium hydroxide was used, and a simple chelation procedure with EDTA was followed to stabilize the Cr(III) species in standard solutions. ICP-MS results indicated the feasibility of using chromium isotope m/z 53 instead of the more abundant m/z 52 isotope due to a high mobile-phase background most significantly from the SO+ polyatomic interference. The absolute detection limits based on peak-height calculations were 40 pg for Cr(III) and 100 pg for Cr(VI) in aqueous media by HPLC-ICP-MS. The linear dynamic range extended from 5 ppb (ng/ml) to 1 ppm (micrograms/ml) for both species. By HPLC-ICP-AES, detection limits were 100 ng for Cr(III) and 200 ng for Cr(VI). Cr(III) was detected in NIST-SRM 1643c (National Institute of Standards and Technology-Standard Reference Material, Trace Elements in Water) by HPLC-ICP-MS at the 20 ppb level.

Chromium determination by supercritical fluid chromatography with inductively coupled plasma mass spectrometric and flame ionization detection.

Supercritical fluid chromatography (SFC) has been investigated for the separation of a pair of beta-ketonate chromium compounds and a thermally labile organochromium dimer. A limited comparison between flame ionization detection (FID) and inductively coupled plasma mass spectrometric (ICP-MS) detection of these compounds is presented. The beta-ketonate complexes were observed with both detectors, while the thermally labile dimer was not observed with ICP-MS detection. Detection limits for these compounds with ICP-MS were in the range of 0.9 to 3 pg with FID giving values between 10 and 250 pg. Reproducibility of the method is between 1 and 4% relative standard deviation (R.S.D.). The technique provided a linear response over approximately three orders of magnitude. The effect of two mobile phases (nitrous oxide and carbon dioxide) on the detection by each of the detectors are presented in a qualitative manner. Finally, the SFC-ICP interface heating method and the manner in which the restrictor is heated in the FID system are compared and there effect on the chromatography discussed.

Supercritical fluid extraction of organotins from biological samples and speciation by liquid chromatography and inductively coupled plasma mass spectrometry.

Supercritical fluid extraction is used to extract tributyltin and triphenyltin from biological samples. The extraction conditions with carbon dioxide as supercritical fluid (methanol modifier used) are optimized for the organotins from fish tissue certified reference material. The total extraction time is found to be approximately 15 min. The recovery studies at the optimal conditions shows a recovery of 44% for tributyltin and 23% for triphenyltin. The reproducibilities for both the compounds extracted are within 2% R.S.D. The optimum conditions obtained are also used to extract tributyltin and triphenyltin from tuna fish obtained from a local grocery store.

Comparison of flame ionization and inductively coupled plasma mass spectrometry for the detection of organometallics separated by capillary supercritical fluid chromatography.

Organotin compounds are separated by capillary supercritical fluid chromatography (SFC) and a comparison of the detection by flame ionization (FID) and inductively coupled plasma mass spectrometry (ICP-MS) is presented. Resolution, detection limits, linear dynamic range and reproducibility are the parameters compared between SFC-FID and SFC-ICP-MS, for the detection of tri- and tetraorganotin compounds. The resolution obtained in the SFC-FID system is not always observed in SFC-ICP-MS. Degradation in resolution is due to fluctuations in transfer line temperature. Baseline resolution for the organotins considered is achieved in both systems by using a longer column. Detection limits (DLs) are calculated as 3 sigma/S, where sigma is the standard deviation of the blank signal and S is the slope of the calibration curve. Detection limits of 10.3, 12.5, 12.0 and 9.0 pg are obtained for tetrabutyltin, tributyltin chloride, triphenyltin chloride and tetraphenyltin, respectively, using SFC-FID. An improvement in detection limits of one order of magnitude is achieved by SFC-ICP-MS for the same organotins (0.26, 0.80, 0.57 and 0.20 pg, respectively). The relative standard deviations using SFC-FID for five 50-nl injections, containing 0.5 ng Sn, ranged from 3.2 to 6.4%. Using SFC-ICP-MS, five replicate injections of 0.05 ng Sn give R.S.D.s from 1.3 to 3.4%.

Evaluation of inductively coupled plasma mass spectrometry as an elemental detector for supercritical fluid chromatography.

Supercritical fluid chromatography coupled with inductively coupled plasma mass spectrometry shows high potential for the determination at ultratrace levels of organometallic compounds of environmental interest. In this study the determination of organotin compounds at ultratrace levels is demonstrated. In this work a supercritical fluid chromatography/inductively coupled plasma mass spectrometry (SFC/ICPMS) interface was developed. Separation of tetraalkyltin compounds shows detection levels in the subpicogram range (0.034 pg for tetrabutyltin; 0.047 pg for tetraphenyltin). The linear ranges are over 3 orders magnitude (1-1000 pg). The reproducibility of sample injections are better than 5% RSD.