Trace phthalate and adipate esters contaminated in packaged food

A method for trace analysis of two plasticizers, di-2-ethylhexyl phthalate (DEHP) and di-2-ethylhexyl adipate (DEHA), contaminated in packaged curry paste were investigated by gas chromatography with flame ionization detector (GC-FID). Curry paste samples were extracted by ultrasonic and solid phase extraction using Florisil(R) cartridge. Analysis by the GC-FID system provided limits of detection for DEHA and DEHP at 12 and 25 microg L(- 1) and a linear dynamic range between 25 microg L(- 1) to 60 mg L(- 1) with a coefficient of determination (R(2)) greater than 0.99. High recoveries were obtained, ranged from 91 to 99% and 88 to 98% for DEHP and DEHA with RSD lower than 7 and 10% respectively. The method detection limit and limits of quantitation were ranged from 27 to 30 and 90 to 100 microg L(- 1). The analysis of curry paste samples showed concentrations of DEHP and DEHA in the range of 4.0 ng g(- 1) to 0.61 microg g(- 1).     

Preliminary toxicological assessment of phthalate esters from drinking water consumed in Portugal

This paper reports, for the first time, the concentrations of selected phthalates in drinking water consumed in Portugal. The use of bottled water in Portugal has increased in recent years. The main material for bottles is polyethylene terephthalate (PET). Its plasticizer components can contaminate water by leaching, and several scientific studies have evidenced potential health risks of phthalates to humans of all ages. With water being one of the most essential elements to human health and because it is consumed by ingestion, the evaluation of drinking water quality, with respect to phthalate contents, is important. This study tested seven commercial brands of bottled water consumed in Portugal, six PET and one glass (the most consumed) bottled water. Furthermore, tap water from Lisbon and three small neighbor cities was analyzed. Phthalates (di-n-butyl phthalate ester (DnBP), bis(2-ethylhexyl) phthalate ester (DEHP), and di-i-butyl phthalate ester (DIBP)) in water samples were quantified (PET and glass) by means of direct immersion solid-phase microextraction and ionic liquid gas chromatography associated with flame ionization detection or mass spectrometry due to their high boiling points and water solubility. The method utilized in this study showed a linear range for target phthalates between 0.02 and 6.5 μg L^?1, good precision and low limits of detection that were between 0.01 and 0.06 μg L^?1, and quantitation between 0.04 and 0.19 μg L^?1. Only three phthalates were detected in Portuguese drinking waters: dibutyl (DnBP), diisobutyl (DIBP), and di(ethylhexyl) phthalate (DEHP). Concentrations ranged between 0.06 and 6.5 μg L^?1 for DnBP, between 0.02 and 0.16 μg L^?1 for DEHP, and between 0.1 and 1.89 μg L^?1 for DIBP. The concentration of DEHP was found to be up to five times higher in PET than in glass bottled water. Surprisingly, all the three phthalates were detected in glass bottled water with the amount of DnBP being higher (6.5 μg L^?1) than in PET bottled water. These concentrations do not represent direct risk to human health. Regarding potable tap water, only DIBP and DEHP were detected. Two of the cities showed concentration of all three phthalates in their water below the limits of detection of the method. All the samples showed phthalate concentrations below 6 μg L^?1, the maximum admissible concentration in water established by the US Environmental Protection Agency. The concentrations measured in Portuguese bottled waters do not represent any risk for adult's health.     

Free Fatty Acids and Sterols in Swine Manure

Free fatty acids and sterols were assessed in fresh manure and anaerobic lagoon sludge from swine production facilities in North Carolina. Eight free fatty acids and five sterols were identified and quantified in both manure and sludge samples. Compound identification was performed by gas chromatography/mass spectroscopy (GC-MS), and compound quantities were determined by gas chromatography after solid phase extraction with a 50:50 mixture of diethyl ether and hexane. The free fatty acids occurring in greatest abundance in both fresh manure and lagoon sludge were palmitic, oleic, and stearic. Free fatty acid content in fresh manure ranged from approximately 3 μ g g^?1 dry weight (dw) to over 45 μ g g^?1 dw. In lagoon sludge, free fatty acid content ranged from about 0.8 μ g g^?1 dw to nearly 4 μ g g^?1 dw. Coprostanol and epicoprostanol were the sterols in largest concentrations in fresh manure and lagoon sludge samples. Total sterol content ranged from approximately 0.5 μ g g^?1 dw to around 11 μ g g^?1 dw in fresh manure and from 3.5 μ g g^?1 dw to almost 9 μ g g^?1 dw in lagoon sludge. Fresh manure and lagoon sludge both had high levels of inorganic cations (e.g., Ca, Mg, Fe) capable of binding free fatty acids and forming insoluble complexes, thereby potentially reducing fatty acid biodegradation. In anaerobic lagoons, sterols are an organic fraction of sludge that are resistant to bacterial degradation. In the case of fresh manure, fatty acids could represent a potential source of energy via the manufacture of biodiesel fuel, if efficient means for their extraction and transesterification can be devised.     

Comparative analysis of trace contaminants in leachates before and after a pre-oxidation using a solar photo-Fenton reaction

Sanitary landfill leachates are a complex mixture of high-strength organic and inorganic persistent contaminants, which constitute a serious environmental problem. In this study, trace contaminants present in leachates were investigated by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector before and after a pre-oxidation step using a solar photo-Fenton process. More than 40 organic compounds were detected and identified as benzene (0.09?±?0.07 mg?L^-1), trichlorophenol (TCP) (0.18?±?0.12 mg?L^-1), phthalate esters (Di-n-butyl phthalate (DBP), Butyl benzyl phthalate (BBP), Di(2-ethylhexyl) phthalate (DEHP)) (DBP: 0.47?±?0.01 mg?L^-1; BBP: 0.36?±?0.02 mg?L^-1; DEHP: 0.18?±?0.01 mg?L^-1), among others. Toluene, pentachlorophenol, dimethyl phthalate, diethyl phthalate, and Di-n-octyl phthalate were never detected in any of the samples. After the photo-Fenton treatment process, TCP decreased to levels below its detection limit, benzene concentration increased approximately three times, and DBP concentration decreased about 77 % comparatively to the raw leachate sample. The solar photo-Fenton process was considered to be very efficient for the treatment of sanitary landfill leachates, leading to the complete elimination of 24 of the detected micropollutants to levels below their respective detection limits and low to significant abatement of seven other organic compounds, thus resulting in an increase of the leachate biodegradability.     

Elemental uptake by edible herbs and lettuce (Latuca sativa)

The total concentration of toxic elements (aluminum, cadmium, chromium and lead) and selected macro and micro elements (iron, manganese, copper and zinc) are reported in six leafy edible vegetation species, namely lettuce, spinach, cabbage, chards and green and red types of Amaranth herbs. Although spinach and chards had greater than 125 mv of iron, both the amaranthus herbs recorded > than 320 μ g g^{? 1} dry weight. In both the spinach and chard species, the Mn and Zn levels were appreciable recording > 225 μ g g^{? 1} and 150 μ g g^{? 1} dry weight, respectively. Aluminum concentrations were (in μ g g^{? 1} dry weight) lettuce (10), cabbage (11), spinach (167), chards (65), amaranthus green (293) and amaranthus red (233). All the micro and macro elements and the toxic elements (Ni, Cr, Cd and Pb) elements analyzed, were below the recommended maximum permitted levels (RMI) in vegetables. Further the elemental uptake and distribution of the nine elements, at three growth stages of the lettuce plant grown on soil bed under controlled conditions are detailed. In the soil, except for iron (16%), greater than 33% of the other cations were in exchangeable form. Generally in the lettuce plant, roots retained much of the iron (> 224 μ g g^{? 1}) and aluminum (> 360 μ g g^{? 1}), while leaves had less than 200 μ g g^{? 1} of iron and 165 μ g g^{? 1} of Al. Although the concentrations of elements marginally decreased with growth, the lettuce leaves had significant amounts of Mn (30 μ g g^{? 1}), Zn (50 μ g g^{? 1}) and Cu (3.6 μ g g^{? 1}). Some presence of lead in leaves (2.0 μ g g^{? 1}) was noticed, but all the toxic and other elements analyzed were well below the RMI values for the vegetables.     

Distribution,source, and environmental risk assessment of phthalate esters (PAEs) in water,suspended particulate matter,and sediment of a typical Yangtze River Delta City,China

Phthalates (PAEs) in drinking water sources such as the Yangtze River in developing countries had aroused widespread concern. Here, the water, suspended particulate matter (SPM), and sediment samples were collected from 15 sites in wet and dry seasons in Zhenjiang, for the determination of six PAEs (DMP, DEP, DIBP, DBP, DEHP, and DOP) using the solid-phase extraction (SPE) or ultrasonic extraction coupled with gas chromatography-mass spectrometry (GC-MS). The total concentrations of six PAEs (Σ₆PAEs) spanned a range of 2.65–39.31 μg L^?1 in water, 1.97–34.10 μg g^?1 in SPM, and 0.93–34.70 μg g^?1 in sediment. The partition coefficients (K_d1) of PAEs in water and SPM phase ranged from 0.004 to 3.36 L g^?1 in the wet season and from 0.12 to 2.84 L g^?1 in the dry season. K_d2 of PAEs in water and sediment phase was 0.001–9.75 L g^?1 in the wet season and 0.006–8.05 L g^?1 in the dry season. The dominant PAEs were DIBP, DBP, and DEHP in water and SPM, DIBP, DEHP, and DOP in sediment. The concentration of DBP in water exceeded the China Surface Water Standard. The discharge of domestic sewage and industrial wastewater might be the main potential sources of PAEs. The risk quotient (RQ) method used for the risk assessment revealed that DBP (0.01 < RQ < 1) posed a medium risk, while DIBP and DEHP (RQ > 1) posed a high environmental risk in water, DIBP (RQ > 1) also showed a high risk in sediment.

     

Assessment of the impact of pesticide residues on microbiological and biochemical parameters of tea garden soils in India

The main aim of this study was to assess the impact of pesticidal residues on soil microbial and biochemical parameters of the tea garden soils. The microbial biomass carbon (MBC), basal (BSR) and substrate induced respirations (SIR), β -glucosidase activity and fluorescein diacetate hydrolyzing activity (FDHA) of six tea garden soils, along with two adjacent forest soils (control) in West Bengal, India were measured. The biomass and its activities and biochemical parameters were generally lower in the tea garden soils than the control soils. The MBC of the soils ranged from 295.5 to 767.5 μ g g^{? 1}. The BSR and SIR ranged from 1.65 to 3.08 μ g CO₂-C g^{? 1} soil h^{? 1} and 3.08 to 10.76 μ g CO₂-C g^{? 1}h^{? 1} respectively. The β -glucosidase and FDHA of the soils varied from 33.3 and 76.3 μ g para-nitrophenol g^{? 1} soil h^{? 1} and 60.5 to 173.5 μ g fluorescein g^{? 1}h^{? 1}respectively. The tea garden soils contained variable residues of organophosphorus and organochlorine pesticides, which negatively affected the MBC, BSR, SIR, FDHA and β -glucosidase activity. Ethion and chlorpyriphos pesticide residues in all the tea garden soils varied from 5.00 to 527.8 ppb and 17.6 to 478.1 ppb respectively. The α endosulfan, β endosulfan and endosulfan sulfate pesticide residues in the tea garden soils ranged from 7.40 to 81.40 ppb, 8.50 to 256.1 ppb and 55 to 95.9 ppb respectively. Canonical correlation analysis shows that 93% of the total variation was associated with the negative impact of chlorpyriphos, β and α endosulfan and endosulfan sulfate on MBC, BSR and FDHA. At the same time ethion had negative impact on SIR and β -glucosidase. Data demonstrated that the pesticide residues had a strong impact on the microbial and biochemical components of soil quality.     

Phthalates and the aquatic environment: Part I The effect of di-2-ethylhexyl phthalate (DEHP) and di-isodecyl phthalate (DIDP) on the reproduction of Daphnia magna and observations on their bioconcentration

$\text{Daphnia magna}$ were exposed to di-2-ethylhexyl phthalate (DEHP) and to di-isodecyl phthalate (DIDP) at nominal concentrations up to 100 μg/1 over a 21 day period. The phthalates had no effect on reproduction, and the parent $\text{Daphnia}$ showed bioconcentration factors of 209 (DEHP) and 116 (DIDP) as determined by ¹⁴C analysis.     

A miniature stainless steel net dumbbell-shaped stir-bar for the extraction of phthalate esters in instant noodle and rice soup samples

Abstract

This work reports the development of a very-simple-to-construct stir-bar extraction device so called “a dumbbell-shaped stainless steel stir-bar.” The extraction device was assembled from a rolled up stainless steel net filled with an XAD-2 sorbent and a metal rod to allow the use of a magnetic stirrer during extraction. The dumbbell-shaped stainless steel stir-bar was used to extract diethyl phthalate (DEP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP) before analysis by a gas chromatograph equipped with an electron capture detector (GD-ECD). Under the optimal conditions, the developed method provided a good linearity from 10.0 to 1,000.0?ng mL^?1 for all three compounds. Limits of detection and limits of quantification were 9.37?±?0.29?ng mL^?1 and 31.22?±?0.95?ng mL^?1 for DEP, 5.73?±?0.31?ng mL^?1 and 19.1?±?1.0?ng mL^?1 for DBP and 3.30?±?0.06?ng mL^?1 and 11.0?±?0.19?ng mL^?1 for DEHP, respectively. Good recoveries in the range of 81.89?±?0.17 to 109.5?±?2.0% were achieved when the method was used to extract phthalate esters in five instant noodle and two rice soup samples.     

Simultaneous analysis of free and sulfo-conjugated steroid estrogens in artificial urine solution and agricultural soils by high-performance liquid chromatography

A simple and robust analytical method was developed to simultaneously detect and quantify 17β-estradiol (E2), estrone (E1), 17β-estradiol-3-sulphate (E2-3S), and estrone-3-sulphate (E1-3S) in aqueous solutions (calcium chloride and artificial urine solutions) and agricultural soils using high performance liquid chromatography and UV detection. The standards for all four compounds were linear in the range of 0.01 to 1.0 μg mL^?1 (n = 6) and 1.0 to 20 μg mL^?1 (n = 6), respectively, with correlation coefficients > 0.999. The on-column limits of detection at an injection volume of 50 μL and S/N (signal: noise) ratio of 3 were: 9.0 ng mL^?1, 10 ng mL^?1, 5.0 ng mL^?1, and 7.0 ng mL^?1 for E2-3S, E1-3S, E2 and E1, respectively. The limit of detection and quantification in artificial urine solution and CaCl₂ solution was 1.0 ng mL^?1 for all four compounds. Method detection limits for the compounds in the 3 soils ranged from 2 to 2.4 ng g^?1 (E2-3S and E1-3S), and 1.0 to 2.9 ng g^?1 (E2 and E1), respectively.     

Influence of air flow rate on emission of DEHP from vinyl flooring in the emission cell FLEC: Measurements and CFD simulation

The emission of di-(2-ethylhexyl)phthalate (DEHP) from one type of vinyl flooring with ～15% (w/w) DEHP as plasticizer was measured at 22 °C in five FLECs + one blank FLEC (Field and Laboratory Emission Cell). Initially, the flow through all FLECs was 450 ml min^?1. After 689 days the flows were changed to 1000 ml min^?1, 1600 ml min^?1, 2300 ml min^?1, and 3000 ml min^?1, respectively, in four FLECs, and kept at 450 ml min^?1 in one FLEC. Air samples were collected from the effluent air at regular intervals. After 1190 days the experiments were terminated and the interior surfaces of all six FLECs were rinsed with methanol to estimate the internal surface concentrations of DEHP. The DEHP air concentration and specific emission rate (SER) at steady state was estimated for the five different flow rates. The steady-state concentrations decreased slightly with increasing air flow with only the two highest flow rates resulting in significantly lower concentrations. In contrast, the SERs increased significantly. Despite large variation, the internal surface concentrations appeared to decrease slightly with increasing FLEC flow. Computational fluid dynamic (CFD) simulations suggest that the interior gas and surface concentrations were roughly uniform for the low flow case (450 ml min^?1), under which, the partitioning between the FLEC internal surface and chamber air was examined. Although paired t-tests showed no difference between CFD and experimental results for DEHP air concentrations and SERs at steady-state conditions, CFD indicated that the experimental DEHP surface concentrations in the FLECs were underestimated. In conclusion, the experiments showed that the emission of DEHP from vinyl flooring is subject to “external” control and that the SER is strongly and positively dependent on the air exchange rate. However, the increased SER almost compensates for the decrease in gas-phase concentration caused by the increased air exchange.     

The effect of pesticides and metals on acetylcholinesterase (AChE) in various tissues of blue mussel (Mytilus trossulus L.) in short-term in vivo exposures at different temperatures

The purpose of the study was to assess the impact of short-term exposure to selected toxicants as well as metal accumulation upon acetylcholinesterase (AChE) in the blue mussel, Mytilus trossulus L., in laboratory in vivo experiments. Mussels were exposed for up to 48 hours to a mixture of copper (Cu^{2 +}, 400 μ g L^?1) and cadmium (Cd^{2 +}, 200 μ g L^?1), to dichlorvos (DDVP, 100 μ g L^?1), and to carbaryl (100 μ g L^?1) at two temperatures: 5°C and 20°C. Samples were collected after 0, 6, 12, 24, and 48 hours of exposure, and AChE activity and metal concentration (where applicable) were analysed in gills, digestive gland, mantle+muscles, and the whole soft tissue. Very strong AChE inhibition was observed in response to the dichlorvos treatment, mainly in gills. Carbaryl and the metals caused a short-term inhibition effect. Considerable differences in AChE activity between the two temperatures were noticed. In particular, the metals were accumulated much faster at 20°C than at 5°C, especially in gills. No correlation between AChE activity and metal concentration was found. Gills turned out to be the optimal tissue for AChE activity analysis in short-term studies.     

Screening Capsicum chinense fruits for heavy metals bioaccumulation

Elevated concentrations of heavy metals in edible plants could expose consumers to excessive levels of potentially hazardous chemicals. Sixty-three accessions (genotypes) of Capsicum chinense Jacq, collected from 8 countries of origin were grown in a silty-loam soil under field conditions. At maturity, fruits were collected and analyzed for seven heavy metals (Cd, Cr, Ni, Pb, Zn, Cu, and Mo) concentrations. The main objectives of this investigation were: 1) to determine the concentrations of seven heavy metals in the soil and monitor their accumulation in mature fruits, 2) to categorize the pepper accessions as low or high heavy metal accumulators, and 3) to determine if heavy metal content of the pepper fruit was lower than the permitted limits. Concentrations and relative proportions of heavy metals in pepper fruits of C. chinense varied among accessions. Fruits of Plant Introduction (PI) 355820 accumulated significant concentrations of Cd (0.47 μ g g^?1dry fruit). PI-260522 accumulated the highest concentration of Pb (2.12 μ g g^?1 dry fruit) among the 63 accessions tested. This accession (PI-260522) contained about twice the Pb limit on a fresh weight basis. Among the 63 accessions analyzed, PI-238051 contained the highest levels of Ni (17.2 μ g g^?1). We concluded that high accumulator genotypes may be useful for phytoremediation, while, low accumulator accessions might be appropriate selections for growing on Cd-, Pb-, or Ni-contaminated soils to prevent potential human exposure to heavy metals and health hazards through the food chain.     

Development,validation, and application of a method for the GC-MS analysis of fipronil and three of its degradation products in samples of water,soil, and sediment

A method for the identification and quantification of pesticide residues in water, soil, and sediment samples has been developed, validated, and applied for the analysis of real samples. The specificity was determined by the retention time and the confirmation and quantification of analyte ions. Linearity was demonstrated over the concentration range of 20 to 120 µg L^?1, and the correlation coefficients varied between 0.979 and 0.996, depending on the analytes. The recovery rates for all analytes in the studied matrix were between 86% and 112%. The intermediate precision and repeatability were determined at three concentration levels (40, 80, and 120 µg L^?1), with the relative standard deviation for the intermediate precision between 1% and 5.3% and the repeatability varying between 2% and 13.4% for individual analytes. The limits of detection and quantification for fipronil, fipronil sulfide, fipronil-sulfone, and fipronil-desulfinyl were 6.2, 3.0, 6.6, and 4.0 ng L^?1 and 20.4, 9.0, 21.6, and 13.0 ng L^?1, respectively. The method developed was used in water, soil, and sediment samples containing 2.1 mg L^?1 and 1.2% and 5.3% of carbon, respectively. The recovery of pesticides in the environmental matrices varied from 88.26 to 109.63% for the lowest fortification level (40 and 100 µg kg^?1), from 91.17 to 110.18% for the intermediate level (80 and 200 µg kg^?1), and from 89.09 to 109.82% for the highest fortification level (120 and 300 µg kg^?1). The relative standard deviation for the recovery of pesticides was under 15%.     

Occurrence and microbial degradation of phthalate esters in Taiwan river sediments

Concentrations and microbial degradation rates were measured for eight phthalate esters (PAEs) found in 14 surface water and six sediment samples taken from rivers in Taiwan. The tested PAEs were diethyl phthalate (DEP), dipropyl phthalate (DPP), di-n-butyl phthalate (DBP), diphenyl phthalate (DPhP), benzylbutyl phthalate (BBP), dihexyl phthalate (DHP), dicyclohexyl phthalate (DCP), and di-(2-ethylhexyl) phthalate (DEHP). In all samples, concentrations of DEHP and DBP were found to be higher than the other six PAEs. DEHP concentrations in the water and sediment samples ranged from ND to 18.5 μg/l and 0.5 to 23.9 μg/g, respectively; for DBP the concentration ranges were 1.0–13.5 μg/l and 0.3–30.3 μg/g, respectively. Concentrations of DHP, BBP, DCP and DPhP were below detection limits. Under aerobic conditions, average degradation half-lives for DEP, DPP, DBP, DPhP, BBP, DHP, DCP and DEHP were measured as 2.5, 2.8, 2.9, 2.6, 3.1, 9.7, 11.1 and 14.8 days, respectively; under anaerobic conditions, respective average half-lives were measured as 33.6, 25.7, 14.4, 14.6, 19.3, 24.1, 26.4 and 34.7 days. In other words, under aerobic conditions we found that DEP, DPP, DBP, DPhP and BBP were easily degraded, but DEHP was difficult to degrade; under anaerobic conditions, DBP, DPhP and BBP were easily degraded, but DEP and DEHP were difficult to degrade. Aerobic degradation rates were up to 10 times faster than anaerobic degradation rates.     

Development and validation of LC-MS/MS method for the determination of Ochratoxin A and its metabolite Ochratoxin α in poultry tissues and eggs

The objective of this study was to develop a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the determination of Ochratoxin A (OTA) and Ochratoxin α (OTα) in poultry tissues and eggs. The two toxins were extracted by a mixture of acetonitrile/water, purified with a reversed phase C18 solid phase extraction column (SPE) and determined by LC-MS/MS. The LC-MS/MS method performances were evaluated in terms of linearity in solvent and in matrix (ranged from 0.5 to 15.10 µg L^?1 for OTA and from 0.60 to 17.85 µg L^?1 for OTα), limit of detection (LOD), limit of quantitation (LOQ), specificity, accuracy and precision in repeatability conditions. Recovery experiments were performed by spiking poultry liver, kidney, muscle and eggs around 1 µg kg^?1 and 10 µg kg^?1. LODs were 0.27 and 0.26 µg kg^?1 while LOQs were fixed at 1.0 and 1.2 µg kg^?1 for OTA and OTα, respectively. Main recoveries for OTA ranged from 82 to 109% and for OTα ranged from 55 to 89%. The values of within-laboratory relative standard deviation (RSD_r) were equal to or below 20%. Considering the results obtained and that all analytical performance criteria were fulfilled, the new extraction and purification method developed for OTA and OTα determination in animal tissues and eggs was found appropriate for control laboratories and research activities designed to ensure food safety.     

Residues levels of organochlorine pesticide in cow's milk from industrial farms in Hidalgo,Mexico

A survey was carried out from 2008 to 2010 to determine the concentrations of 16 organochlorine pesticide residues (OPRs) from Tizayuca, Hidalgo, Mexico. Organochlorine residue determinations were made from milk fat, using chromatographic cleanup and analysis by gas chromatography with an electron capture detector. The OPR concentrations found were from below the detection limit (DL) to 0.91 ng g^?1 in 2008, DL to 0.38 ng g^?1 in 2009 and DL to 0.59 ng g^?1 in 2010. In general concentrations of organochlorine pesticides were higher in the wet season (3.37 ng g^?1 and 4.79 ng g^?1) than the dry season (1.92 ng g^?1 and 2.71 ng g^?1) for 2009 and 2010, due to control of pests in the pasture and sheds. According to Codex Alimentarius regulations, individual pesticides did not exceed the permissible limits, which for example were 10 μg kg^?1 for alpha hexachlorocyclohexane (HCH) and endosulfan I, 20 μg kg^?1 for p,p’-DDT, and 6 μg kg^?1 for dieldrin, endrin and heptachlor. A reduction of organochlorine pesticide concentrations in cow's milk was noted, indicating that the Mexican government has achieved reduction or elimination of some organochlorine pesticides in response to global agreements on persistent organic pollutants.     

Presence of carbamazepine,naproxen, and ibuprofen in wastewater from northern Tunisia

We investigated the occurrence of three pharmaceutical residues in four wastewater treatment plants (WWTPs) from northern Tunisia. The selected compounds were carbamazepine, naproxen, and ibuprofen; they are among the most commonly prescribed and widely used pharmaceutical agents worldwide. Samples (200?mL) were pre-concentrated using the solid phase extraction (SPE) enrichment procedure and the analysis of the pharmaceuticals was performed with high-performance liquid chromatography (HPLC-UV). The overall procedure provided limits of detection (LOD) lower than 0.5 µg.L^?1and recoveries of 78–97%. For the carbamazepine compound, the mean concentrations were 60.58, 93.19, and 132 µg.L^?1 for the Bizerte, Jendouba, and Tunis WWTPs, respectively. This pharmaceutical was not detected in the Beja WWTPs. Naproxen and ibuprofens were not detected in the Jendouba WWTP but were found in the three other WWTPs with concentrations ranging from 2.94 to 36.17 µg.L^?1 and from 8.02 to 43.22 µg.L^?1, respectively. From the obtained data, it seems that these WWTPs are not able to eliminate this kind of micro-pollutants.     

Assessment of Organochlorine Pesticide Residues in Water,Sediment, and Fish of the Songhua River,China

This study examined residual concentrations and associated ecological risks of the organochlorine pesticides (OCPs) hexa- chlorocyclohexane (HCH) and dichloro-diphenyl-trichloroethane (DDT) in water, sediment, and fish of the Songhua River in Zhaoyuan County, China. In June 2012, 10 water, 10 sediment, and 20 fish samples were collected. Residual concentrations of ΣHCH and ΣDDT ranged from 10.0–35.59 ng L^?1 (mean 28.03 ± 11.66 ng L^?1) and 5.12–39.66 ng L^?1 (mean 32.36 ± 11.58 ng L^?1) for water. Residual concentrations of ΣHCH and ΣDDT ranged from 0.52–3.00 ng g^?1 (mean 2.04 ± 0.73 ng g^?1) and 0.34–3.41 ng g^?1 (mean 2.38 ± 0.92 ng g^?1) for sediment. The ratios of α-HCH/γ-HCH were close to 1 at the majority of sampling points, indicating considerable new pollution from the use of lindane. The ratios of p,p′-DDE + p,p′-DDD/ΣDDT were less than 0.5, indicating recent inputs from DDT impurities in dicofol. All HCH and DDT isomers except for p,p′-DDD were detected in fish tissue samples, but the associated ecological risks were estimated to be below levels of concern. The study revealed a historical usage of OCPs in the Zhaoyuan section of the Songhua River and new OCP from the use of lindane and dicofol.     

Ultrasensitive determination of carbendazim in water and orange juice using a carbon paste electrode

A carbon paste electrode was used for the electrochemical quantification of carbendazim in water and orange juice samples. Carbendazim oxidation on the electrode surface was found to be controlled by adsorption. The novel electrochemical procedure for carbendazim quantification employed differential pulse voltammetry using a carbon paste electrode under optimal conditions. Carbendazim oxidation currents were linear at concentrations of 2.84 to 45.44 µg L^?1, with a limit of detection of 0.96 µg L^?1. The proposed method was applied to carbendazim quantification in ultrapurified water, river water, and orange juice. Recovery rates in water and orange juice samples were in the 97%–101% range, indicating that the method can be employed to determine carbendazim in these matrices, with advantages including shorter analysis time and lower cost than routine methods such as chromatography or spectroscopy. The electrode showed good reproducibility, remarkable stability, and especially good surface renewability by simple mechanical polishing. The recovery rates observed were highly concordant with those obtained for high-performance liquid chromatography, having a relative standard deviation of less than 1.3%.