中药材黄芪中有机磷农药残留量的超高效液相色谱-串联质谱法研究

目的:建立了中药材黄芪中25种有机磷杀虫剂残留量的超高效液相色谱-串联质谱(UPLC-MS/MS)检测方法。方法:样品中的有机磷农药残留物经乙腈提取,PSA固相萃取柱(填料为N-丙基乙二胺)净化,丙酮-正己烷(20∶80)洗脱,最后采用超高效液相色谱-电喷雾串联质谱法在正离子多反应监测(MRM)扫描模式下进行测定。结果:25种有机磷农药成分在各自的线性范围内,线性关系良好,相关系数在0.993和0.999之间。在LOQ、5LOQ和10LOQ 3个添加浓度水平进行了添加回收率试验,平均回收率在74.1%和94.4%之间,RSD在2.5%和12.4%之间。各种有机磷农药成分的定量限在2～120μg·kg-1。结论:该方法操作简便,净化效果好,灵敏度、准确度和精密度均符合多残留检测技术的要求,可为中药材中有机磷农药污染状况调查提供新检测方法支持。     

GC-MS法测定银杏叶中3种氨基甲酸酯类农药的残留量

目的:建立银杏叶中3种氨基甲酸酯农药残留量的测定方法。方法:样品以丙酮超声提取,并采用弗罗里硅土柱进行净化,选用气相色谱与质谱串联技术(GC-MS)在DB-5MS毛细管柱上用程序升温技术分离,采用选择离子检测方式,以保留时间和特征离子进行目标成分的定性鉴别,外标法对样品进行测定。结果:3种氨基甲酸酯农药在100～1000μg.L-1范围内呈良好的线性关系,3种农药的方法定量限在5.0～6.0μg.kg-1,3个水平添加回收率在83.30%～89.53%之间,RSD小于10%(n=9)。结论:本方法灵敏度高,重现性好,可用于银杏叶中3种氨基甲酸酯类农药残留的检测。     

气相色谱双塔双柱法同时测定中药材中56种有机氯类及拟除虫菊酯类农药残留量

研究中药材中有机氯类及拟除虫菊酯类农药残留量的测定方法。样品经高速均质器均质提取, 依次经凝胶渗透色谱 (GPC) 和固相萃取柱 (SPE) 净化后, 用气相色谱双塔双柱进样, 双电子捕获检测器同时定性、定量测定。在3种中药材样品基质、3水平添加条件下, 56种农药的回收率大多在70.0%～110.0%, 相对标准偏差小于15%, 检测限大多低于0.01 mg·kg⁻¹, 符合农药多残留检测的要求。本法净化效果好、基质干扰小、灵敏度高、重现性好, 可用于中药材样品中有机氯类及拟除虫菊酯类农药残留量的检测。     

分散固相萃取法与酶抑制法测定8种不同部位中药材农药残留

目的建立分散固相萃取法(QuEChERS)农残净化,结合酶抑制原理,采用紫外分光光度法快速检测8种不同部位中药材中的农药残留。方法样品中加入无水硫酸镁和氯化钠各0.5g,混匀,乙腈提取,经含有C_(18)、PSA(N-丙基乙二胺)和GCB(石墨化碳黑)的固相萃取小柱净化,根据酶抑制原理,利用紫外分光光度法进行农药残留的快速检测。结果有机磷及氨基甲酸酯类农药的质量浓度在一定范围内与抑制率I呈线性关系,该方法用于中药材的样品处理,重复性范围为4.1%~11.2%。结论该方法快捷、简便,适合8种不同部位中药材中农药残留的快速初步检测。     

固相萃取-毛细管气相色谱法测定莪术中15种有机氯农药的残留量

目的用固相萃取-毛细管气相色谱分析方法测定莪术中15种有机氯农药残留量。方法样品以混合溶剂超声提取、Florisil固相萃取小柱净化处理后,采用DB-1701毛细管气相色谱柱分离样品,电子捕获检测器检测。内标法定量,计算有机氯农药的残留量。结果15种农药在5~500μg.L-1范围内具有良好的线性关系,相关系数均大于0.995。15种农药3个不同浓度的平均回收率为83.1%~110.6%,RSD%为3.4%~14.8%。最小检测量为0.08~1.5μg.L-1。被测样品中均含有不同程度的有机氯农药。结论本法简便、灵敏、准确、重现性好,可用于中药材中有机氯类农药的残留量测定。     

气相色谱-质谱联用法测定浙贝母中20种农药残留

目的:建立一种同时测定浙贝母中20种有机氯、拟除虫菊酯类农药残留量的分析方法。方法:样品用乙腈超声提取,经过Florisil固相萃取柱净化样品,用GC-MS选择离子模式进行测定,采用内标法进行定量,以3个添加水平测定样品的回收率和RSD。结果:回收率在67.7%～131.8%之间,RSD均低于15%。各农药检测限均小于0.01 mg.kg-1。结论:采用该方法测定浙贝母中20种有机氯及拟除虫菊酯类农药残留量,简单,快速,准确,灵敏,且重复性好,可用于浙贝母中多种农药残留的同时测定。     

固相萃取-毛细管气相色谱法测定黄芪中多种有机氯农药残留量

目的:建立黄芪中20种有机氯农药残留量的固相萃取——毛细管气相色谱(SPE-CGC)分析方法。方法:样品以乙酸乙酯超声波提取,弗罗里硅土固相萃取快速净化提取物。采用 DB-1701与 DB-5弹性石英毛细管柱分离样品,GC-ECD 检测黄芪药材中20种有机氯农药的残留量。以保留时间定性,标准曲线定量。结果:20种农药的峰面积与其质量浓度均有良好的线性关系,相关系数均大于0.995。最小检测量为0.020～0.299ng·mL~(-1),农药的三个水平添加回收率都在74%～110%之间,相对标准偏差在3.5%～15%之间。结论:该法简便快速、灵敏准确,可用于各类中草药有机氯农药残留量测定。     

固相萃取毛细管气相色谱法测定党参、龙胆中15种有机氯农药的残留量

目的用固相萃取毛细管气相色谱分析方法测定党参、龙胆2种中药材中15种有机氯农药残留量。方法样品以混合溶剂超声提取、Florisil固相萃取小柱净化处理后,采用DB 1701毛细管气相色谱柱分离样品,电子捕获检测器检测,内标法定量。结果15种农药在5~500μg.L-1内具有良好的线性关系,相关系数均大于0.995 0。15种农药3个不同质量浓度的平均回收率为83.1%~110.6%,RSD为3.4%~14.8%。最小检测量为0.08~1.50μg.L-1。被测样品中均含有不同程度的有机氯农药。结论本法可用于中草药党参和龙胆中有机氯类农药的残留量测定。     

GC-MS/MS法同时测定三七片和三七胶囊中24种农药残留量

目的建立同时测定三七片和三七胶囊中24种农药残留量的分析方法。方法样品经丙酮超声提取后用固相分散法(PSA和C18)净化,采用GC-MS/MS法进行测定。结果方法回收率在70%~119%之间,RSD值均低于15%,符合农药多残留测定要求。农药检测限均不高于0.01mg·kg~(-1)。结论该方法简单、快速、灵敏、重复性好,可用于三七片和三七胶囊中24种农药残留量的测定。     

GC-MS法同时测定中药材中29种农药残留量

目的建立一种可同时对29种有机氯、有机磷类农药残留量进行定量检测的方法。方法利用GC-MS技术,配合负化学源检测器,采用选择离子检测法(SIM)进行定量,以石油醚-丙酮混合溶剂为洗脱溶剂,样品通过Florisil硅土柱净化,选择环氧七氯为内标物。结果对48种中药材进行了检测;除敌敌畏、杀虫脒、磷丹及三唑磷外,其余农药的检测限都在0.2～15 g.kg-1之间;以9种中药材为例检测,大部分农药的回收率在70%～120%之间。结论该方法简单、快捷、经济,分析结果达到农残分析的要求,适合大批量样品的同时检测。     

Role of B-esterases in assessing toxicity of organophosphorus (chlorpyrifos, malathion) and carbamate (carbofuran) pesticides to Daphnia magna

In this study, the cladoceran Daphnia magna was exposed to two model organophosphorous and one carbamate pesticides including malathion, chlorpyrifos and carbofuran to assess acetylcholinesterase (AChE) and carboxylesterase (CbE) inhibition and recovery patterns and relate those responses with individual level effects. Our results revealed differences in enzyme inhibition and recovery patterns among the studied esterase enzymes and pesticides. CbE was more sensitive to organophosphorous than AChE, whereas both CbE and AChE showed equivalent sensitivities to the carbamate carbofuran. Recovery patterns of AChE and CbE activities following exposure to the studied pesticides were similar with 80-100% recoveries taking place 12 and 96 h after exposure to organophosphorous and carbamates pesticides, respectively. The physiological role of AChE and CbE inhibition patterns in Daphnia was examined by using organophosphorous and carbamate compounds alone and with specific inhibitors of CbE. Under exposure to organophosphorous pesticides, survival of Daphnia juveniles was impaired at AChE inhibition levels higher than 50% whereas under exposure to the carbamate carbofuran low levels of AChE inhibition affected mortality. Inhibition of CbE by 80-90% increased toxicity to organophosphorous and carbamate pesticides by up to two- and four-fold, respectively. Our results suggest that both AChE and CbE enzymes are involved in determining toxicity of Daphnia to the studied chemicals and that AChE inhibition levels higher than 50% can be considered of environmental concern to Daphnia species.     

Comparison of acute neurobehavioral and cholinesterase inhibitory effects of N-methylcarbamates in rat.

While the cholinesterase-inhibiting N-methyl carbamate pesticides have been widely used, there are few studies evaluating direct functional and biochemical consequences of exposure. In the present study of the acute toxicity of seven N-methyl carbamate pesticides, we evaluated the dose-response profiles of cholinesterase (ChE) inhibition in brain and erythrocytes (RBCs) as well as motor activity (both horizontally and vertically directed) and clinical signs of overt toxicity. The chemicals tested were carbaryl, carbofuran, formetanate, methiocarb, methomyl, oxamyl, and propoxur. All were administered orally, and rats were tested in 20-min activity sessions beginning 15 min after dosing; tissues were collected immediately after activity sessions. In general, motor activity was a sensitive measure of ChE inhibition for all these carbamate pesticides, and vertical activity showed the greatest magnitude of effect at the highest doses compared to either horizontal activity or ChE inhibition. Brain and RBC ChE activities were generally affected similarly. Pearson correlation coefficients of within-subject data showed good correlation between the behavioral and biochemical end points, with brain ChE inhibition and horizontal activity showing the highest correlation values. Determination of benchmark dose levels for 10% change in each end point also revealed that these two measures produced the lowest estimates. Thus, motor activity decreases are highly predictive of ChE inhibition for N-methyl carbamates, and vice versa.     

Selective effects of carbamate pesticides on rat neuronal nicotinic acetylcholine receptors and rat brain acetylcholinesterase

Effects of commonly used carbamate pesticides on rat neuronal nicotinic acetylcholine receptors expressed in Xenopus laevis oocytes have been investigated using the two-electrode voltage clamp technique. The potencies of these effects have been compared to the potencies of the carbamates to inhibit rat brain acetylcholinesterase. The potency order of six carbamates to inhibit alpha4beta4 nicotinic receptors is fenoxycarb > EPTC > carbaryl, bendiocarb > propoxur > aldicarb with IC50 values ranging from 3 microM for fenoxycarb to 165 microM for propoxur and >1 mM for aldicarb. Conversely, the potency order of these carbamates to inhibit rat brain acetylcholinesterase is bendiocarb > propoxur, aldicarb > carbaryl > EPTC, fenoxycarb with IC50 values ranging from 1 microM for bendiocarb to 17 microM for carbaryl and > mM for EPTC and fenoxycarb. The alpha4beta2, alpha3beta4, and alpha3beta2 nicotinic acetylcholine receptors are inhibited by fenoxycarb, EPTC, and carbaryl with potency orders similar to that for alpha4beta4 receptors. Comparing the potencies of inhibition of the distinct subtypes of nicotinic acetylcholine receptors shows that the alpha3beta2 receptor is less sensitive to inhibition by fenoxycarb and EPTC. The potency of inhibition depends on the carbamate as well as on a combination of alpha and beta subunit properties. It is concluded that carbamate pesticides affect different subtypes of neuronal nicotinic receptors independently of acetylcholinesterase inhibition. This implicates that neuronal nicotinic receptors are additional targets for some carbamate pesticides and that these receptors may contribute to carbamate pesticide toxicology, especially after long-term exposure.     

GC-MS法测定18种药材中的农药残留量

目的建立测定18种中药材及饮片中有机磷和氨基甲酸酯类农药残留量的GC-MS方法。方法样品经乙腈-丙酮超声提取,经无水硫酸钠-硅镁型吸附剂-无水硫酸钠色谱柱净化,用GC-MS法测定18种中药材及饮片中有机磷和氨基甲酸酯类农药的残留量。结果有机磷和氨基甲酸酯类农药残留量测定的线性范围为0.8~3.2ng,相关系数r≥0.990,平均回收率为56.2%~118.5%,重复性RSD值为0.2%~11.2%,稳定性RSD值小于3%。其中敌敌畏、仲丁威、二嗪农、抗蚜威和马拉硫磷在107批药材中的含量均小于0.15mg·kg-1。结论该方法灵敏度高,净化效果好,符合农药残留的检测要求。     

Relative inhibition of rat plasma and erythrocyte cholinesterases by pesticide combinations

A selected combination of carbamate pesticides (carbofuran, oxamyl and propoxur were examined for cholinesterase (ChE) inhibition. The enzyme source was rat plasma and erythrocytes. Enzyme activity was determined colorimetrically using the Ellman technique adapted for erythrocyte ChE activity. Enzyme inhibition was obtained for both plasma and erythrocyte ChE, but inhibition by the pesticides was greater in the plasma. All 3 pesticides interacted additively in vitro.     

The effects of anticholinergic insecticides on human mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are located primarily in the bone marrow and are characterized by their capacity to differentiate into mesenchymal lineages such as bone, fat, and cartilage in response to appropriate signals. Several signaling mechanisms act to control MSC survival, proliferation, and differentiation, and failure or disruption of these signaling pathways can lead to degenerative disease or neoplasia. Organophosphate (OP) and carbamate pesticides, which are used in large amounts in agriculture to control insects, are designed to disrupt acetylcholine signaling by inhibiting the enzyme acetylcholinesterase (AChE). Effects of OP and carbamate pesticides on the human central nervous system have been well documented. However, AChE is broadly distributed, and the effects of anticholinergic insecticides on nonnervous tissue have received little attention. In the present study we found that human MSCs express AChE, which makes these cells potential targets for AChE inhibiting agents. We therefore examined the effects of an OP pesticide, chlorpyrifos, and a carbamate, carbofuran, on MSC characteristics. It was found that micromolar concentrations of these anticholinergic insecticides had no effect on MSC survival or proliferation but limited MSC differentiation capacity by inhibiting osteogenic differentiation. These results demonstrate that exposure to micromolar concentrations of OP and carbamate pesticides may affect tissue turnover and pathophysiology by interfering with MSC regulation.     

Common causes of poisoning in dogs and cats in a Brazilian veterinary teaching hospital from 1998 to 2000

A retrospective study at the University Veterinary Teaching Hospital of S?o Paulo city, Brazil, describes the pattern of poisoning that occurred from 1998 to 2000. During this period 5,136 animals were sent to the emergency sector, and 250 of these cases were reported as poisonings: 203 dogs (81.2%) and 47 cats (18.8%). The common causes of poisoning in dogs were 28.9% therapeutic products (86.4% non-steroidal anti-inflammatory drugs, 6.8% other drugs, 3.4% antibiotics, 3.4% tranquilizing agents), 15.8% rodenticides, 13.9% pesticides for farm use (39.3% organophosphorous and 35.7% carbamate insecticides, 25.0% amitraz), 11.8% unknown agents, 8.4% plants, 6.8% industrial products, and 5.0% pesticides for domestic use. The common causes of poisoning in cats were 29.9% therapeutic products (50.0% non-steroidal anti-inflammatory drugs, 42.8% others, 7.2% antibiotics), 27.6% pesticides for farm use (46.1% carbamate insecticides, 38.5% organophosphorous insecticides, 15.4% others), 14.9% pesticides for domestic use, 12.8% unknown agents, 10.6% rodenticides, and 4.2% industrial products. These data show it is essential to create an awareness of the toxicity of these agents to reduce poisoning incidence.     

Use of esterase activities of the zebra mussel (dresissena polymorpha pallas) as a biomarker of organophosphate and carbamate pesticides contamination

The inhibition of acetylcholinesterase (AChE) and carboxylic esterase (CbE) activities was measured in the zebra mussel, Dreissena polymorpha, in view of the possible impact of organophosphate and carbamate pesticides. Three experimental designs were performed: (a) in vitro studies in which the inhibition of both AChE and CbE activities was measured after incubation of homogenate of soft tissues of mussels with a range of organophosphate and carbamate insecticides, aldicarb, carbofuran, chlorfenvinphos, dichlorvos, dimethoate, malathion, parathion, tetrachlorvinphos, and the oxon of parathion and malathion (paraoxon and malaoxon, respectively); (b) in vivo assays with native mussels exposed to a carbamate pesticide, aldicarb; and (c) in situ studies of the level of esterase activity found in mussels collected on several stations on Lake Geneva. The results showed that the zebra mussel has a measurable, but low, level of AChE activity, and a higher level of CbE activity. However, this latter activity was not very sensitive to inhibition by these toxic compounds. Inhibition in the field was not demonstrated, but significant modifications of the protein content of the mollusks were shown. It was concluded that CbE was not a promising and reliable biomarker to assess the toxic effects of organophosphate and carbamate pesticides in the field. © 1996 by John Wiley & Sons, Inc.     

Impacts of carbamate pesticides on olfactory neurophysiology and cholinesterase activity in coho salmon (Oncorhynchus kisutch)

Many freshwater aquatic environments in the Pacific Northwest of North America contain neurotoxic pesticides, an issue of concern given the use of many of these habitats by Pacific salmon (Oncorhynchus sp.). Pesticides such as carbamates are known to affect fundamental physiological systems (such as the enzyme acetylcholinesterase (AChE)), and have been shown to affect salmonid olfactory-mediated behaviors. A neurophysiological measure of olfactory function, the electro-olfactogram (EOG), was used in this study to examine the impacts of acute localized exposure to three carbamates (the insecticide carbofuran, the antisapstain IPBC, and the fungicide mancozeb) on olfactory function in the coho salmon (Oncorhynchus kisutch). We also examine the potential for these pesticides to alter AChE levels in the primary olfactory system and brain with brief exposures (30 min to only the olfactory rosette (OR)). In results, we find that the EOG in coho salmon is highly sensitive to brief localized exposures of two of these three carbamate pesticides. The effective nominal concentration required to cause a 50% reduction in EOG amplitude (EC50) for carbofuran was 10.4 microg/l and for IPBC was 1.28 microg/l. For mancozeb, the EC50 was higher at 2.05 mg/l. All three carbamates also affected AChE activity levels in the OR and brain (BR): carbofuran exposure at 200 microg/l significantly inhibited AChE activity in the OR, and both IPBC and mancozeb significantly increased AChE activity in BR at multiple concentrations with acute localized exposure. These carbamate effects highlight the sensitivity of salmon olfactory neurophysiology to pesticides acting not only potentially via AChE-inhibition, but also by other currently unknown modes of action.     

Poisoning of an urban family due to misapplication of household organophosphate and carbamate pesticides.

A case report of an urban family who experienced excessive exposure to organophosphate and carbamate pesticides is presented. All three family members developed symptoms that were compatible with cholinesterase inhibition: headache, lightheadedness, wheezing, shortness of breath, nausea, and fatigue. Serial measurement of red blood cell and serum cholinesterases soon after exposure and during subsequent months confirmed the diagnosis of pesticide poisoning. This report demonstrates that the misapplication of pesticides commonly used in residences in urban areas can cause acute pesticide poisoning and demonstrates the usefulness of repeated measurements of cholinesterase during the post-exposure period in establishing the correct diagnosis.