Modified QuEChERS extraction method followed by simultaneous quantitation of nine multi-class pesticides in human blood and urine by using GC-MS.

Organophosphate, carbamate and pyrethroid pesticides are the most common insecticides used worldwide. They may cause chronic poisoning in farmers and acute poisoning in homicidal or suicidal cases. The determination of trace levels of these pesticides in human blood and urine is very challenging. This study focuses on a simultaneous quantitation method that was developed and validated for multi-class nine pesticides belonging to organophosphate, carbamate and pyrethroid classes in human blood and urine. Target pesticides were extracted from blood and urine using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction method. Capillary column DB-35 ms (15 m × 0.25 mm, 0.25 µm) was used for chromatography with a 0.079 ml/min flow rate of carrier gas at constant pressure mode. Quantitation of sulfotep, phorate, carbofuran, chlorpyriphos, profenophos, triazophos, pyriproxyfen, lambda-cyhalothrin and permethrin was performed by mass spectrometer equipped with electron impact ionization source using selected ion monitoring (SIM) mode. The lower and upper limits of quantitation for all nine pesticides were 0.01 mg/L and 2.0 mg/dL respectively. The proposed method was proved to be simple, fast, sensitive, and robust. It has been applied to the analysis of 9 pesticides samples.

Salt-assisted acetonitrile extraction and HPLC-QTOF-MS/MS detection for residues of multiple classes of pesticides in human serum samples.

Detecting pesticide residues in human serum is a challenging process. In this study we developed and validated a method for the extraction and recovery of residues of multiple classes of pesticides from serum using one reagent. Salt-assisted acetonitrile extraction and high-performance liquid chromatography with quadrupole time of flight tandem mass spectrometry were used to quantitate 34 pesticides classified in nine groups of chemicals in human serum samples, which are frequently detected in food. The recoveries for 33 of analyzed pesticides ranged from 86 to 112% with relative standard deviations below 15%. The limits of quantitation and linearity of 31 of the pesticides were 1 µg/L and >0.990, respectively. The lower limit of quantitation has been reported in the literature particularly for multi-classes pesticide mixtures in human serum. The salt-acetonitrile reagent was allowed to achieve good recoveries and detection limits, which could be attributed to salt altering the solvent polarity, preferentially collecting the organic phase in the solution, and promoting the extraction. The developed method was applied for two organophosphate pesticide metabolites, diethylphosphate and 3,5,6-trichloro-2-pyridinol, in serum from rats that were fed a nonlethal quantity of chlorpyrifos. The concentrations of these two were 252.18 ± 15.47 and 0.63 ± 0.23 µg/L, respectively.

[Simultaneous determination of 21 organophosphrous pesticides in human serum by QuEChERS-gas chromatography-mass spectrometry].

Objective: A method for the simultaneous determination of organophosphrous pesticides inhuman serum was developed. Methods: Using C18 and PSA as absorbent, 21 organophosphrous pesticides including methamidophos, dichlorvos, acephate, Omethoate, demeton and etc. in human serum were determined by combing QuEChERS with GC-MS, organophosphrous pesticides were qualitatedsimultaneously by retention time and characteristic ions. Their contents were determined by internal standard method of quantitative ions. Results: The linear range was from0to 0.60µg/ml with a good correlation coefficients (r ≥ 0.9961) . The LODs of this methodranged from 0.0009 to 0.0111 µg/ml. The average recoveries of3 organophosphrous pesticides (methamidophos、dichlorvos and acephate) ranged from 71.8%~85.3%, The average recoveries of other 18 organophosphrous pesticidesranged from 82.9%~102.9%. The relative standard deviations were0.8%~7.0%. Conclusion: The convenient operation and versatility of this method are suitable forthe fast screening and accurate detection of 21 organophosphrous pesticides in human serum.

Health Risk Assessment of Occupationally Pesticide-Exposed Population of Cancer Prone Area of Punjab.

The alarming health issues especially the unusually high number of cancer cases in agriculture community of Bathinda district of Punjab (India) is a serious concern. There is limited knowledge about the role of gene-environment interactions in oncogenesis prevalent in this area. The aim of this study was to evaluate the association of oxidative stress with CYP1A2, CYP2B6, CYP2C9, CYP3A4, and PON1 genetic variation in the pesticide-exposed (occupationally) population of Bathinda district of Punjab (India). This study demonstrated significantly elevated relative risk (RR) of lower antioxidant defense mechanism (Glutathione, Catalase, Superoxide Dismutase, Glutathione peroxidases, and Glutathione Reductase) in occupationally pesticide-exposed group (n = 120) as compared with unexposed group (n = 84) from Bathinda district of Punjab (India). Our data shows pesticide exposure to be a major risk factor leading to increased oxidative stress inside the body. Gas chromatographic analysis revealed the residues of organophosphates (chlorpyriphos, dichlorvos, ethoprophos) and herbicides (atrazine, butachlor, alachlor, metolachlor) in the blood samples of the exposed population. In vitro results showed a dose dependent decrease in cell viability following treatment of pesticides detected in blood samples in hPBMCs and A549 cell line. Genetic variation analysis revealed missense mutations in CYP2B6 (2 mutations), CY3A4 (1 mutation), and CYP2C9 (2 mutations). The observed mutations have been predicted to cause structural and conformation change in protein structure which could result in altered stability. In first of its kind of study, our data reveal oxidative stress and pesticide residue accumulation inside the body to be the major reasons for health concerns in Bathinda district.

Background biomonitoring of residue levels of 137 pesticides in the blood plasma of the general population in Beijing.

Due to the widespread use of pesticides, human exposure to pesticides is possible and can potentially cause adverse impacts on public health. We measured 137 pesticides including organophosphorus, organochlorine, pyrethroid and carbamate pesticides together with various herbicides in 100 human blood samples collected from the general population in Beijing. The samples were analysed by triple quadrupole tandem gas chromatography-mass spectrometry. In total, 24 organochlorine pesticides, 5 pyrethroid pesticides and 6 organophosphorus pesticides were detected. The detection rates of HCB, α-HCH, ß-HCH, γ-HCH, p,p'-DDE and quintozene were 99, 96, 74, 72, 96 and 95%, respectively. No statistically significant gender difference in the blood concentrations of the pesticides was found. Consistent with the trend of the increasing ß-HCH, p,p'-DDE and quintozene concentrations with age, a strong positive correlation between the age and concentrations of ß-BHC, p,p'-DDE and quintozene was observed.

Monitoring of organochlorine pesticides in blood of women with uterine cervix cancer.

In Yucatan, Mexico, chronic exposure of Mayan population to pesticides is expected as about 30 per cent are drinking polluted water. Residues of organochlorine pesticides (OCP) were monitored in 18 municipalities of Yucatan with high mortality rates due to uterine cervix cancer. 70 blood samples collected from Mayan women living in livestock, agricultural and metropolitan area were analyzed for OCP. Solid Phase Extraction was performed on C18 cartridges and analyzed by Gas Chromatography with Electron Capture Detector. The results showed that the highest OCP levels were detected in blood of women living in the livestock area. OCP detected were endosulfan I (7.35 µg/mL), aldrin (3.69 µg/mL), 4,4' DDD (2.33 µg/mL), 1.39 and 1.46 µg/mL of δ-HCH. Women from the agricultural area had high concentrations of OCP in their blood, particularly dieldrin (1.19 µg/mL), and 1.26 µg/mL of 4,4' DDE. In the metropolitan area, 0.080 µg/mL of γ-HCH and 0.064 µg/mL of heptachlore were detected. This monitoring study was also based on epidemiological data of uterine cervical cancer. It was found that environmental factors may have facilitated the infiltration of OCP to the aquifer used for potable water supply. These factors in addition to poverty can have impacts on public health. This first exploratory study suggests that monitoring of OCP in human is important for the establishment of health promotion programs. The integrative analysis of both, environmental and social factors would be helpful to characterize the bioaccumulation of pesticides in humans.

Hematological and hepatic alterations in Brazilian population heavily exposed to organochlorine pesticides.

The aim of this study was to investigate the frequency of hematological and hepatic alterations and possible association with serum levels of beta-hexachlorocyclohexane (beta-HCH), p,p'-DDE, and hexachlorobenzene (HCB) among residents in an area heavily contaminated with organochlorine (OC) pesticides. A cross-sectional study was conducted in 415 male and 432 female residents aged >14 years. Serum samples were collected and analyzed for OC pesticides concentrations and biochemical parameters. Frequencies of hematological and hepatic alterations were calculated for each gender. Association between beta-HCH, p,p'-DDE (1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene), and HCB levels and presence of alterations was determined by logistic regression stratified by gender and controlling for confounders. Highest frequencies were observed for eosinophilia (23% men and 18% women), low hemoglobin (12% men and 15% women), and low erythrocyte count (12% men). High levels of bilirubin, glutamic-oxaloacetic transaminase (GOT), and glutamic-pyruvic transaminase (GPT) were observed, respectively, in 10, 11, and 12% of men and <10% of women. Gamma-glutamyl transferase (GGT) was elevated in 26 and 25% of males and females, respectively. Multivariate analysis revealed associations between eosinophilia and beta-HCH in men (OR = 1.06, 95%CI = 1.01-1.12) and women (OR = 1.05, 96%CI = 0.99-1.11), p,p'-DDE in men (OR = 1.03, 95%CI = 0.99-1.06) and women (OR = 1.02, 95%CI = 0.99-1.06), and HCB in women (OR = 1.54, 95%IC = 0.85-4.45). Beta-HCH was found to be associated with increased risk of elevated bilirubin in females (OR = 1.18, 95%CI = 1.07-1.29) and males (OR = 4.21, 95%CI = 1.87-9.47 for fourth vs. first quintile). Thus, OC pesticides may exert adverse effects on hematopoietic tissue and liver in populations chronically exposed to high levels of these compounds.

A review of methods for the analysis of orphan and difficult pesticides: glyphosate, glufosinate, quaternary ammonium and phenoxy acid herbicides, and dithiocarbamate and phthalimide fungicides.

This article reviews the chromatography/MS methodologies for analysis of pesticide residues of orphan and difficult chemical classes in a variety of sample matrixes including water, urine, blood, and food. The review focuses on pesticide classes that are not commonly included in multiresidue analysis methods such as highly polar or ionic herbicides including glyphosate, glufosinate, quaternary ammonium, and phenoxy acid herbicides, and some of their major degradation or metabolite products. In addition, dithiocarbamate and phthalimide fungicides, which are thermally unstable and have stability issues in some solvents or sample matrixes, are also examined due to their special needs in residue analysis.

[Exposure to persistent and non-persistent pesticides in a non-occupationally exposed population in Tenerife Island (Spain)]. / Exposición a plaguicidas persistentes y no persistentes en población no expuesta laboralmente de la isla de Tenerife.

OBJECTIVE: Chronic exposure to non-persistent pesticides (NPPs) is of concern because these substances have been associated with chronic diseases. However, few studies have addressed chronic exposure to NPPs in Spanish populations. METHODS: We determined the presence of 24 pesticide residues by gas chromatography/mass spectrometry in 363 serum samples obtained from non-occupationally exposed adults from Tenerife island in 2007. RESULTS: Most of the samples (99.45%) showed detectable residues (6 ± 2 pesticides per sample). The most frequently detected pesticides were pyrethrins (96.1%), organophosphates (93.9%) and organochlorines (92.3%). The neurotoxicants bifenthrin and malathion were detected in 81% of the samples and hexachlorobenzene DDT and buprofezin in more than 50%. Malation, an "environmental obesogen", was detected in 82%, and "endocrine disrupter" pesticides were present in 97.2% of the samples. CONCLUSIONS: Because there is clear, continuous and inadvertent exposure to NPPs that may be inducing adverse effects on human health, NPPs should be included in biomonitoring studies.

Determinación de residuos de plaguicidas en trabajadores agrícolas del municipio de Barcelona, Quindío, Colombia / Determination of pesticide levels in farmers working in the Barcelona municipality, Quindio, Colombia

Objetivos: En este trabajo se determinaron los niveles de residualidad de plaguicidas organoclorados y organofosforados en muestras de sangre periférica de trabajadores agrícolas –fumigadores– en el municipio de Barcelona, Quindío, Colombia. Método: Los trabajadores fueron escogidos al azar dentro de los principales cultivos abastecedores de frutas y verduras de la región. Para la extracción y determinación de los analitos en sangre, se usó la técnica de micro-extracción en fase sólida en modo head space y cromatografía de gases capilar dotado con un detector de micro captura de electrones. Resultados: Como resultado se encontraron residuos de 21 plaguicidas de tipo organoclorados y organofosforados; la mayoría de estos en alta concentración (>0.01 ppm) y prohibidos por la legislación nacional e internacional, sugiriendo que aún siguen siendo utilizados ilegalmente. De la residualidad encontrada, los plaguicidas más representativos fueron: beta-BHC y endosulfan, hallados en el 50 por ciento de las personas evaluadas. Asimismo, se descubrió que entre el 20 y 40 por ciento de las personas tenían residuos de endrin aldehído, forato, sulfotep, disulfoton y thionazin, en circunstancia que la mayoría de estos son de categoría toxicología I y II, comprobando el alto riesgo al que se exponen constantemente los individuos que aplican estos compuestos y la falta de atención e información por parte de las entidades responsables de autorización y fiscalización de su uso. Conclusiones: En este sentido, los resultados encontrados en este trabajo demuestran la importancia de continuar con los estudios de monitoreo y control de calidad de los principales alimentos, fuentes hídricas y trabajadores agrícolas, para así informar a la población acerca de los riesgos a los que está expuesta.

Aim: To determine the levels of organochlorine and organophosphorus pesticide residues in peripheral blood samples of farm-workers in Barcelona, Quindío, Colombia. Methods: Farm-workers were randomly chosen to cover the major suppliers of fruits and vegetables crops in the region. Solid phase micro extraction in head space mode and capillary gas chromatography with a micro electron capture detector were used for extraction and determination of analytes from blood. Results: Twenty-one pesticides residues among organochlorine and organophosphorusclasses were found. Most of these pesticides were at high concentrations (>0.01 ppm) and represented concentrations forbidden by national and international legislation. Beta-BHC and endosulfan were found in 50 percent of persons tested. Residues of endrinaldehyde, phorate, sulfotep, disulfoton and thionazinwere found amongst 20-40 percent of the persons tested. Conclusions: These results demonstrate the high risks that farm-workers are exposed to, suggesting poor attention and provision of information by entities responsible for permits and supervision. Furthermore, we highlight the need for monitoring and quality control of food, water sources and farm-workers, and the necessity to inform workers and the community of the risks to which they are exposed.

[Determination of 15 kinds of pesticides in blood by gas chromatography-mass spectrometry].

OBJECTIVE: To develop the method of gas chromatography-mass spectrometry (GC-MS) for simultaneous determination of 15 herbicides in blood. METHODS: 2ml of blood in vitro were sampled, concentrated and extracted with dichloromethane, reconstant with methanol agents of Gulonic acid lactone solution, and detected by GC-MS. RESULTS: Experimental results show that diazinon, atrazine, prometryn, methyl parathion, butachlor, bifenthrin at 4-80 microg/L, phorate, malathion, 2,4-D butyl ester, chlordane, fenpropathrin at 10-200 microg/L, alpha-endosulfan, beta-endosulfan, cyhalothrin at 20-400 microg/L, dimethoate at 40-800 microg/L, with good linear response. The correlation coefficient (r2) were between 0.998-1.000, respectively. The recovery of all analysts averaged between 56%-128% in blood samples. The detection limits of all compounds between 0.05 and 1.00 microg/L. The lower limit of quantification between 0.20 and 3.001 microg/L. CONCLUSION: The methods is apply to detect the content of analysts in blood samples.

[Method establishment for the determination of 8 organophosphorus pesticides in serum using LC/MS/MS].

OBJECTIVE: To establish the method to determine the presence and concentration of 8 organophosphors pesticides in serum by LC/MS/MS. METHOD: The serum samples were extracted by ethyl acetateether and then separated on C18 5 microm (2.1 mm x 150 mm) column with pH = 3.5 acid-ammonium acetate buffer solution, methanol--water as mobile phase to mixed gradient elution. Electro-spray ionization source (ESI) was applied and operated in positive ion mode, and multiple reaction monitoring(MRM) mode was adopted. RESULT: Within concentration ranging from 0-1000 ng/ml the correlation coefficient for each compound was greater than 0.990, recoveries were between 95%-129%, RSD < 7.9%. The RSD of intra-day and inter-day were less 12% (n = 6). CONCLUSION: The procedure of preparing serum samples is sample and the result of this method is efficient, accurate and specific.

Associations between organochlorine pesticides and vitamin D deficiency in the U.S. population.

BACKGROUND: Recently low dose organochlorine (OC) pesticides have been strongly linked to various chronic diseases including diabetes and cardiovascular diseases. Both field and animal studies have suggested a possibility that persistent lipophilic chemicals like OC pesticides can cause vitamin D deficiency, but there have been no human studies of exposure to any chemical as a possible cause of vitamin D deficiency. This study was performed to examine if serum concentrations of OC pesticides were associated with serum concentrations of 25-hydroxyvitamin D (25(OH)D) in the U.S. general population. METHODOLOGY/PRINCIPAL FINDINGS: Cross-sectional associations of serum OC pesticides with serum 25(OH)D were investigated in 1,275 subjects aged ≥20 in the National Health and Nutrition Examination Survey (NHANES), 2003-2004. We selected 7 OC pesticides detectable in ≥80% of participants. Among the 7 OC pesticides, p,p'-DDT (ß = -0.022, P<0.01), p,p'-DDE (ß = -0.018, P = 0.04), and ß-hexachlorocyclohexane (ß = -0.022, P = 0.02) showed significant inverse associations with serum 25(OH)D levels. When study subjects were stratified by age, race, and the presence of various chronic diseases, p,p'-DDT showed consistent inverse associations in all subgroups, although stronger associations tended to be observed among subjects with old age, white race, or chronic diseases. CONCLUSION/SIGNIFICANCE: The current study suggests that the background exposure to some OC pesticides leads to vitamin D deficiency in human. Considering the importance of vitamin D deficiency in the development of chronic diseases, chemical exposure as a possible cause of vitamin D deficiency should be evaluated in prospective and experimental studies.

Pesticide exposure and serum organochlorine residuals among testicular cancer patients and healthy controls.

The incidence of testicular cancer (TC) has been increasing worldwide during the last decades. The reasons of the increase remains unknown, but recent findings suggest that organochlorine pesticides (OPs) could influence the development of TC. A hospital-based case-control study of 50 cases and 48 controls was conducted to determine whether environmental exposure to OPs is associated with the risk of TC, and by measuring serum concentrations of OPs, including p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) isomer and hexachlorobenzene (HCB) in participants. A significant association was observed between TC and household insecticide use (odds ratio [OR] = 3.01, 95 % CI: 1.11-8.14; OR(adjusted) = 3.23, 95 % CI: 1.15-9.11). Crude and adjusted ORs for TC were also significantly associated with higher serum concentrations of total OPs (OR = 3.15, 95 % CI: 1.00-9.91; OR(adjusted) = 3.34, 95 % CI: 1.09-10.17) in cases compared with controls. These findings give additional support to the results of previous research that suggest that some environmental exposures to OPs may be implicated in the pathogenesis of TC.

Incidence of organochlorine pesticides and the health condition of nestling ospreys (Pandion haliaetus) at Laguna San Ignacio, a pristine area of Baja California Sur, Mexico.

We identified and quantified organochlorine (OC) pesticide residues in the plasma of 28 osprey (Pandion haliaetus) nestlings from a dense population in Laguna San Ignacio, a pristine area of Baja California Sur, Mexico, during the 2001 breeding season. Sixteen OC pesticides were identified and quantified. α-, ß-, δ- and γ-hexachlorocyclohexane, heptaclor, heptachlor epoxide, endosulfan I and II, endosulfan-sulfate, p,p'-DDE, p,p'-DDD, aldrin, dieldrin, endrin, endrin aldehyde, and endrin ketone were the OCs found in the plasma of nestlings, ranging from 0.002 to 6.856 pg/µl (parts per billion). No differences were found in the concentration of pesticides between genders (P > 0.05). In our work, the concentrations detected in the plasma were lower than those reported to be a threat for the species and that affect the survival and reproduction of birds. The presence of OC pesticides in the remote Laguna San Ignacio osprey population is an indication of the ubiquitous nature of these contaminants. OCs are apparently able to travel long distances from their source to the study area. A significant relationship between hemoglobin and mean corpuscular hemoglobin concentrations and OC concentrations were found suggesting that a potential effect on the health of chicks may exist in this osprey population caused by the OC, e.g. anemia. The total proteins were positively correlated with α-BHC, endosulfan I, and p,p'-DDD. It has been suggested that OC also affects competitive interactions and population status over the long term in vertebrate species, and our results could be used as reference information for comparison with other more exposed osprey populations.

Effects of co-existed proteins on measurement of pesticide residues in blood by gas chromatography-mass spectrometry.

Accurate measurement of pesticides in biological fluids such as blood is important for quantifying environmental exposures. Beyond sample enrichment and separation, the method presented here is focused on studies of interactions between pesticides and co-existed proteins. It was experimentally demonstrated that entrapped or adsorbed pesticide residues within the folded native structures of proteins were poorly recovered using direct solvent extraction solely. We described here an effective approach termed Enzymatic Digestion-Organic Solvent Extraction (eDOSE) that utilizes the enzymatic approach to disrupt the folded structures of proteins and release entrapped or adsorbed pesticide residues. In this approach, samples were first reduced, alkylated, tryptically digested and then diluted 10 times before the subsequent extraction using an n-hexane solution. Resultant pesticide residues were determined by capillary gas chromatography coupled with a mass spectrometer. Mean recoveries of the 5 organophosphorus pesticides pre-spiked in fish blood including diazinon, parathion-methyl, malathion, parathion-ethyl and ethion were 85%, 95%, 84%, 103%, and 43% respectively using eDOSE strategy but only 24%, 45%, 40%, 27%, and 29% respectively using direct solvent extraction approach. The eDOSE approach was effective for demonstrating the critical role of folded native structure of serum albumin in adsorption of exogenous chemicals. It provides an alterative means for denaturation of proteins when the target analytes are not stable in acidic solution or entrapped within the protein aggregates caused by organic solvents such as acetone that have been applied for protein denaturation. The eDOSE approach should be able to combine with other advanced techniques of enrichment and separation for more efficient and accurate measurement of target compounds present in the context of complex biological systems. This approach can provide wide applications to the analysis of a variety of small molecules including environmental pesticide residues and metabolites as well as other toxins present in cells, tissues and biofluids.

Dioxin-like activity in the blood of Greenlandic Inuit and Danish women: a pilot study.

OBJECTIVES: (1) To determine whether plasma dioxin-like (DL) bioactivity differs between Inuit living in different Greenlandic districts, (2) to compare the DL activity of the Inuit having high burdens of POPs with a low-burden study group (Danish volunteers), and (3) to evaluate DL activity associations to POP exposure biomarkers and/or lifestyle factors. STUDY DESIGN: The study was a cross-sectional survey, including randomized inhabitants (70) from 6 different Greenlandic districts and young Danish volunteers (22). METHODS: POPs and fatty acids profiles were analysed. Aryl hydrocarbon receptor (AhR) mediated DL-activity was determined by exposure of Hepa1.12cR AhR-CALUX reporter cell line to hexane: ethanol plasma extracts. RESULTS: The sum PCBs/POPs level of Inuit was more than 10 times higher than the levels found in Danish volunteers, and for both study groups the level was positively associated with age. The TCDD equivalent of the determined DL-activity, AhR-TEQ, differed between the Greenlandic districts. The AhR-TEQ data of the combined Inuit was significantly higher compared with the Danish women. AhR-TEQ of Inuit were positively associated with plasma POPs after adjustment for age and/or the ratio of n-3 to n-6 fatty acids, whereas no correlations were found for the Danish samples. CONCLUSIONS: AhR-TEQ differs between Inuit and Danish plasma samples. Plasma POP levels alone cannot be used as a biomarker for DL-activity. We suggest that the profile and level of plasma POPs, geographical location and diet have the greatest impact on plasma dioxin activity. Further studies are needed to elucidate the differences in geographical determinants of blood DL-activity.

Insulin-like growth factor-I (IGF-I) serum concentrations in healthy children and adolescents: relationship to level of contamination by DDT-derivative pesticides.

CONTEXT: Serum levels of Insulin-like growth factor I (IGF-I) play a critical role in children growth and in the pathogenesis of several diseases. In addition, recent studies suggest that DDT-derivative organochlorine pesticides (OC-DDTs) could influence IGF levels in human beings. OBJECTIVE AND DESIGN: Because it has been suggested that IGF-I peak levels at puberty could determine IGF-I levels in adulthood, we developed a cross-sectional study of the potential association between serum levels of OC-DDTs and IGF system in 160 serum samples from young people (81 boys and 79 girls) living in the Canary Islands (Spain). RESULTS: Multivariate tests were used adjusting for confounding variables (age, height, and weight) and stratifying by gender and age: IGF-I serum levels were significantly lower in pre-pubertal male children (6-15years) who showed detectable values of p,p'-DDE, and p,p'-DDD than in pre-pubertal male children with undetectable levels of these OC-DDTs-metabolites (p=0.023 and p=0.049, respectively). In addition, in this multivariate model, a non-linear dose-response curve was observed between Total DDT body burden (sum of the three DDT-derivatives measured: p,p'-DDT, p,p'-DDE, and p,p'-DDD) and IGF-I in pre-pubertal male children (6-15years; p=0.043). CONCLUSION: These findings suggest that OC-DDTs could modulate the IGF-system in a way that is highly influenced by gender and age. Improvements in our understanding of exogenous determinants of the IGF-system may provide new insights into the role played by environmental contaminants in IGF-related diseases.

[Residuals of organochlorine pesticides and heavy metals in soil and water of planting base and Liriope muscari].

OBJECTIVE: To analyze the residuals of organochlorine pesticides and heavy metals in soil, water and Radix Liriopes from planting bases in Quanzhou city, and evaluate the quality of the herb. METHOD: GC method was applied to determine residuals of organochlorine pesticides, the contents of Pb, Cd, Cu, Cr, and As were determined by IPC. RESULT: The contents of residuals of organochlorine pesticides and heavy metals varied among the samples of soil, water and Radix liriopes, but all of the residuals met requirement of the national standard. CONCLUSION: Residuals of organochlorine pesticides and heavy metals in soil, water and Radix liriopes from planting bases in Quanzhou city were conformed to GAP.

[Rapid identification of 22 abused drugs and organophosphorus pesticides in blood by LC-MS/MS].

OBJECTIVE: To develop a method for rapid identification of 22 abused drugs and organophosphorus pesticides in the blood. METHODS: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) in multiple-reaction monitoring mode (MRM) was employed for detecting the drugs and pesticides in the blood. The MRM database and criteria for identification were established, and ethyl acetate was used for extraction of the drugs. After 3 rounds of extractions of the blood sample (1 mL) using 2 mL ethyl acetate, the extract was vortexed for 3 min and centrifuged at 5000 r/min. Each organic phase was combined and evaporated by gentle N2 gas. The residue was re-dissolved in 100 L mobile phase, from which 5 L was taken for LC-MS/MS detection. RESULTS: The detection of the 22 target compounds could be completed within 10 min. The limit of detection of the target compound ranged from 0.03 to 6.00 ng/ml. Satisfactory results were obtained in proficiency testing program organized by China National Accreditation Service for Conformity Assessment. CONCLUSION: The method we established is rapid, selective and sensitive for detecting the 22 abused drugs and organophosphorus pesticides.