高效液相色谱-串联质谱法测定蔬菜中氟虫腈及其代谢物残留

目的 建立了蔬菜中氟虫腈及其代谢物氟甲腈、氟虫腈砜和氟虫腈亚砜的高效液相色谱-串联质谱法。方法 用乙腈超声提取样品中的氟虫腈及其代谢物,高速离心后,提取液经QuChERS净化管净化,过0.22μm滤膜,经Waters Acquity UPLC HSS T3色谱柱分离,以乙腈-0.1%甲酸水(含5mmol/L乙酸铵)做流动相,梯度洗脱,采用电喷雾离子源负离子检测模式(ESI-)和多重反应监测(MRM)模式测定,基质匹配标准曲线定量。结果 在蔬菜基质中,被测物在1.0 μg/L～100 μg/L内相关系数均>0.999,平均回收率范围为97.8%～109%,相对标准偏差(RSD)为1.0%～7.7%,检出限为0.02μg/kg～0.10μg/kg,定量限为0.06μg/kg～0.30μg/kg。结论 该方法操作简单、准确、快速、灵敏度高,适用于蔬菜中氟虫腈及其代谢物残留的检测。     

液相色谱-串联质谱检测鸡蛋中氟虫腈及其代谢物的残留量

目的建立一种检测鸡蛋中氟虫腈及其代谢物残留的液相色谱-串联质谱(LC-MS/MS)定量分析方法。方法优化检测条件:用乙腈进行样品提取,选择C18固相萃取小柱和无水硫酸镁对提取样品净化后进行液质联用检测。结果经过优化后液相条件:流动相由2mmol/L的甲酸铵水溶液和甲醇组成,采用梯度洗脱方式在C18反相色谱柱中进行分离,进样量为4μL。质谱条件:离子源采用ESI负离子,通过SRM模式对样品中氟虫腈及其代谢物进行定量检测。优化后,氟虫腈及其代谢物在0~20ng/mL质量浓度范围内线性关系良好,R2均>0.9993,检出限(S/N=3)和定量限(S/N=10)分别0.2~0.4μg/kg和0.66~1.32μg/kg。实际样品中添加4.0、20.0、40.0μg/kg 3个质量浓度水平下,平均回收率在76.60%~98.24%,相对标准偏差(RSD)为1.03%~3.41%,符合定量检测要求。结论该方法操作简便、灵敏度高,可满足鸡蛋中氟虫腈及其代谢物的检测要求。     

改良的QuEChERS与超高效液相色谱三重四极杆质谱法检测动物源性食品中胺苯醇类药物残留

目的建立改良的QuEChERS与超高效液相色谱三重四极杆质谱法(HPLC-MS/MS)检测动物源性食品中胺苯醇类药物的检测方法。方法样品经改进的QuEChERS方法提取净化,以氨化乙腈为提取剂,正己烷、乙二胺-N-丙基硅烷(PSA)净化粉、十八烷基硅烷键合硅胶(C₁₈)净化粉净化,Waters ACQUITY UPLC BEH C₁₈(2.1 mm×100 mm,1.7μm)柱色谱柱分离,超高效液相色谱三重四极杆质谱仪检测,外标法定量分析。结果采用本法测定,氯霉素、氟苯尼考胺、氟苯尼考和甲砜霉素得到很好的分离,在一定范围内呈现良好的线性关系。氯霉素的检出限为0.04μg/kg,氟苯尼考胺的检出限为2.0μg/kg,氟苯尼考和甲砜霉素的检出限为0.4μg/kg。样品的加标回收率为77.28%~104.5%,RSD在3.02%~6.49%。结论该方法实现了4种胺苯醇类药物残留的自动化、快速、高灵敏度和高稳定性分析,能够满足目前动物源性食品中胺苯醇类药物残留的检测限量的要求。     

固相萃取-气相色谱质谱联用法测定茶叶中溴虫腈和茚虫威

目的建立同时测定茶叶中溴虫腈和茚虫威的气相色谱-质谱联用(GCMS)检测方法。方法样品经乙腈均质,提取离心,提取液经CARB/NH2柱净化后,再经SLH小柱净化,以DB-5MS毛细柱(30 m×0.25 mm×0.25μm)分离后,在选择离子扫描模式(SIM)下进样分析,外标法定量。结果该法对于溴虫腈和茚虫威的线性范围均为0.10~10μg/m L,测定茶叶样品的检出限分别为0.01和0.008 mg/kg,定量限分别为0.03和0.025 mg/kg。加标回收率为75.6%~92.7%,相对标准偏差为3.6%~11.4%(n=6)。结论该法净化效果好,结果准确,适用于茶叶样品中溴虫腈和茚虫威的同时检测。     

鸡蛋和“小众”禽蛋中氟虫腈及其代谢物残留状况调查

目的 了解鸡蛋和“小众”禽蛋中氟虫腈及其代谢物的残留状况。方法 采用超高效液相色谱-电喷雾串联质谱法对近年于江西市场上采样的159批市售鲜禽蛋中氟虫腈及其3种代谢物进行了检测,分析了不同蛋种中氟虫腈及其代谢物的残留状况。结果 159批样本中共检出35批仅含有4种化合物中的一种,且仅检出氟甲腈和氟虫腈砜两种代谢物,氟虫腈砜主要是鸡蛋和鹌鹑蛋检出,检出率12.6%,氟甲腈主要是鸭蛋检出,检出率9.4%。结论 鲜禽蛋中氟虫腈及其代谢物的残留量远低于国内外限量,安全尚可,但整体检出的样本数依然提示出要密切关注家禽养殖圈杀虫剂的使用。     

植物性食品中氟虫腈及其代谢物残留的分散固相萃取净化-气相色谱质谱检测法

目的探索建立应用分散固相萃取净化-气相色谱质谱同时检测植物性食品中氟虫腈及其代谢物的方法。方法样品经乙腈提取,加入无水硫酸钠脱水,氯化钠离心分层后取有机相以N-丙基乙二胺(PSA)和无水硫酸镁作为分散固相萃取试剂去除杂质,浓缩后以丙酮定容,气相色谱质谱检测。对超声提取的试剂和温度以及PSA用量进行优化,获得最佳的超声萃取条件,优化质谱条件。结果氟虫腈及其代谢物在0.05～1.00μg/mL浓度范围内线性关系良好(r值为0.999 1～0.999 9),检出限为0.001 mg/kg,低、中、高3个加标水平下回收率分别为83.7%～87.8%、84.2%～89.1%、80.3%～86.9%,相对标准偏差(RSD)为2.6%～6.3%。结论该方法操作简便,试剂消耗量少,结果准确,精密度高,适合同时测定植物性食品中氟虫腈及其代谢物农药残留。     

固相萃取-气质联用法测定蔬菜中氟虫腈和溴虫腈残留

目的建立蔬菜中氟虫腈和溴虫腈残留的固相萃取-气相色谱/质谱分析方法。方法试样经乙腈提取,硫酸镁和氯化钠盐析,通过比较PSA柱、石墨化碳/NH_2柱、中性氧化铝柱、Qu Ch ERS净化管4种小柱,对蔬菜中氟虫腈和溴虫腈的吸附和净化情况,选取PSA固相萃取柱进行净化,GC-MS测定,外标法定量。结果该方法在5μg/L~100μg/L具有良好的线性关系(相关系数均0.999),氟虫腈和溴虫腈的回收率分别为93.1%~99.2%和97.4%~100.0%,相对标准偏差(RSD)分别为3.5%~8.6%、2.8%~6.1%,检出限为1.0μg/kg~2.0μg/kg,定量限为3.0μg/kg~6.0μg/kg。应用该方法对90份蔬菜样品进行分析,检出2份阳性样品。结论该方法的灵敏度、精密度和LOD均符合残留分析要求,具有简便、准确、成本低的特点,适用于蔬菜中氟虫腈和溴虫腈农药残留的检测。     

气相色谱-质谱法测定鸡蛋中氟虫腈的3种前处理方法比较

目的考察比较用AOCA 2007.01方法、SPE方法、Lipono净化管提取法3种不同的前处理方法对鸡蛋中氟虫腈残留量进行定量分析。方法分别采用AOCA 2007.01方法、SPE方法、Lipono净化管方法提取法3种不同的方法对鸡蛋进行前处理,以环氧七氯为内标物,采用气相色谱-质谱法(GC-MS)进行含量测定。结果采用AOCA 2007.01方法、SPE方法、Lipono净化管提取法,氟虫腈的LOD在0.016μg/kg~0.026μg/kg,LOQ在0.054μg/kg~0.086μg/kg,氟虫腈在0.01μg/ml~0.5μg/ml内呈良好的线性关系,加标回收率均在77.0%~123.5%。结论 3种前处理方法均适用于鸡蛋中氟虫腈的测定。     

固相萃取高效液相色谱串联质谱法同时测定蜂蜜中甲硝唑、氯霉素、甲砜霉素和氟甲砜霉素残留

目的建立蜂蜜中甲硝唑(MTZ)、氯霉素(CAP)、甲砜霉素(TAP)和氟甲砜霉素(FF)残留的固相萃取液相色谱质谱分析方法。方法以氘代氯霉素(D5-CAP)和氘代甲硝唑(D4-MTZ)为内标,试样经乙酸乙酯提取,MCS固相萃取柱净化,用乙酸乙酯洗脱氯霉素类抗生素,5%氨化甲醇洗脱甲硝唑,吹干浓缩后,分别先加入0.10 ml甲醇超声溶解残留物,再加入0.90 ml 10%甲醇/水溶液混匀,经Shim-pack XR-ODS C18色谱柱分离,以0.1%甲酸水-甲醇做流动相,梯度洗脱,氯霉素类抗生素采用ESI-监测模式、甲硝唑采用ESI+监测模式,均采用同位素内标法定量。结果该方法在0.1μg/L~10μg/L呈良好的线性,相关系数均0.999,甲硝唑、氯霉素、甲砜霉素和氟甲砜霉素的回收率为90.6%~110.3%,相对标准偏差(RSD)为1.5%~6.1%,检出限为0.005μg/kg~0.02μg/kg,定量限为0.015μg/kg~0.06μg/kg。结论该方法操作简便、准确、检出限低、重现性好,适用于蜂蜜中甲硝唑、氯霉素、甲砜霉素和氟甲砜霉素残留的检测。     

分散固相萃取-气相色谱-三重四级杆串联质谱法测定代用茶中14种农药残留北大核心CSCD

目的建立了分散固相萃取(d-SPE)-气相色谱-三重四级杆串联质谱法(GC-MS/MS)测定代用茶中14种农药残留的分析方法。方法用乙腈提取样品中待测组分,提取物经N-丙基乙二胺(PSA)分散固相萃取净化后,以DB-5MS柱(30 m×0.25 mm,0.25μm)进行色谱分离,采用GC-MS/MS在多反应监测(MRM)模式下检测,外标法定量。结果在一定的含量范围内线性关系良好,相关系数r≥0.999,方法定量限4~40μg/kg。以空白基质进行3个水平(20、40和200μg/kg)的加标回收实验,平均回收率为65.6%~116.6%,相对标准偏差(RSDs)为1.5%~15.7%(n=6)。结论该方法简单快速、灵敏度高、选择性好,可满足常用代用茶中农药多残留同时分析的要求。     

Persistence and movement of fipronil termiticide with under-slab and trenching treatments

To have an effective barrier against invading termites around building structures and to assess the potential risks to the urban environment and human beings, we need to understand the fate of termiticides applied in urban soil. The movement and degradation of a new termiticide, fipronil, were investigated in Australian soils following standard termiticide treatment methods (surface application under slab and trenching treatments along walls). Surface application studies in three field sites showed slow dissipation and little movement for fipronil in all three soils under the simulated slab during a three-year period. The greatest mass of the chemical residues remained in the quartzite sand layer (thickness, 5 cm), and only small amounts of these were found to have migrated into the soil layers (depth, 0-15 cm) underneath the quartzite sand layer. Of the three metabolites (desulfinyl, sulfide, and sulfone) found in the soils, the sulfone derivative had the highest concentration. Persistence of fipronil was affected by application rate. The time for 50% loss of the total toxic components (fipronil plus its metabolites) in the quartzite sand layer (thickness, 5 cm) ranged from 200 to 326 d for the low rate (0.15 g active ingredient/m2) and from 633 to 674 d for the high application rate (3 g active ingredient/m2). One-year trenching studies at two sites in Adelaide (Roseworthy Farm [RF] and Terretfield [TF]; South Australia, Australia) showed that vertical movement and dissipation of fipronil occurred in the soils. The average concentration of fipronil in the trenches (depth, 0-30 cm) decreased from 33.7 to 14.9 mg/kg in the loam soil at the RF site and from 39.4 to 14.6 mg/kg in the clay soil at the TF site over the year. With time under the natural weather condition, fipronil and its derivatives were found in the deeper soil sections without treatment (depth, 20-30 cm). However, laboratory studies using repacked soil columns showed low mobility in the loam soil from the RF site and a variably charged clay soil from Malanda (Queensland, Australia) under intermittent wetting and drying conditions.     

Fipronil Mobility and Transformation in Undisturbed Soil Columns

The downward movement of fipronil and its two toxic metabolites i.e. sulfone and desulfinyl were studied in undisturbed soil columns. Mobility behavior of two different formulations of fipronil viz granular and suspension concentrate were also studied. The undisturbed columns containing sandy loam soil were leached with water equivalent to 400 mm rainfall. Results revealed that although majority of the fipronil (~80%) remained in top 0–5 cm layer, substantial amount (~15%) moved to 5–10 cm depth. In case of metabolites sulfone and desulfinyl >90% of the residues remained in 0–5 cm core indicating low mobility of these metabolites in comparison to fipronil. Results of mobility behavior of fipronil in granular and SC formulations revealed low mobility in granular formulation. Sulfide was detected as the major degradation product in both the formulations and was found to be distributed throughout the column. A little amount of sulfone (0.1% of the total recovered) was also detected upto 10 cm depth.     

Persistence and Metabolism of Fipronil in Sugarcane Leaves and Juice

Fipronil gives effective control of early shoot borer and termites in sugarcane. The persistence and metabolism of fipronil in sugarcane leaves and juice were studied following application of fipronil (Regent 0.3 G) at 75 and 300 g a.i. ha^?1. Samples of sugarcane leaves were collected at various time intervals. Samples of sugarcane juice were collected at harvest. Residues of fipronil and its metabolites were quantified by gas liquid chromatograph. The limit of quantification of fipronil and its metabolites was 0.01 mg kg^?1 for sugarcane leaves and juice. Total residues of fipronil and its metabolites in sugarcane leaves after 7 days of its application at 75 and 300 g a.i. ha^?1 were 0.26 and 0.66 mg kg^?1, respectively. Residues could not be detected after 60 and 90 following fipronil application at either concentration. In sugarcane leaves, fipronil was found to be the main constituent, followed by its metabolites amide, desulfinyl, sulfone and sulfide. Samples of sugarcane juice did not reveal the presence of fipronil or its metabolites following its application at both the dosages at harvest.     

Photodegradation of Imidacloprid and Fipronil in Rice–Paddy Water

Photodegradation of insecticides, imidacloprid and fipronil, in rice–paddy water under the ambient temperature was investigated. The initial concentrations were set at 58.8 and 3.1 μg/L for imidacloprid and fipronil, respectively, according to their reported initial concentrations in the rice–paddy field. The half-lives (DT₅₀) of imidacloprid and fipronil were 24.2 and 36.7 h, respectively. Fipronil desulfinyl was detected as a major metabolite and fipronil sulfone was found to be a minor metabolite of fipronil in the photodegradation process. Detected mass of fipronil, fipronil desulfinyl, and fipronil sulfone at 79 h were 12.9%, 45.8%, and 5.2% of initial fipronil mass, respectively.     

Persistence and Metabolism of Fipronil in Rice (Oryza sativa Linnaeus) Field

Rice is one of the most important food crops worldwide. However, it is also a valuable tool in assessing toxicity of organic and inorganic compounds. Fipronil insecticide has been widely used to control rice pests. The research was conducted to evaluate the fate of fipronil in rice-field. Persistence and metabolism of fipronil in rice is studied by applications of Regent 0.3G @ 45 and 180 g a.i. ha^?1 was made 7 days after transplanting of paddy. Samples of paddy plants were collected at 7, 15, 30, 45, 60, 90 and 120 days after the application of insecticide. The samples of rice grains, bran, husk and straw were collected at the time of harvest. The samples were extracted and cleaned up by following a standardized methodology. Fipronil and its metabolites were quantified by gas liquid chromatography and confirmed by gas chromatography mass spectrometer. The total residues of fipronil and its metabolites in paddy plants after 7 days of its application at recommend and four times of recommend doses were found to be 6.60 and 19.85 mg kg^?1, respectively. Among fipronil metabolites, sulfone derivative had maximum residue concentration followed by other metabolites viz. sulfide, amide and desulfinyl. The residues were reached below the detectable limit (0.01 mg kg^?1) after 45 and 90 days at recommend and four time of recommend doses, respectively. At harvest, the samples of paddy straw, rice grains, bran and husk did not reveal the presence of fipronil and its metabolites.     

Fate of Fipronil and its Metabolites in/on Grape Leaves, Berries and Soil Under Semi Arid Tropical Climatic Conditions

Fate of fipronil and its major metabolites fipronil sulfide (MB 45950), fipronil-desulfinyl (MB 46513) and fipronil sulfone (MB 46136) were studied in/on grape leaves, berries and soil. As initial residue deposits on the leaves the major component was that of fipronil, while all the 3 metabolites were also present. Among metabolites residues of MB 46513 was highest followed by MB 46136 and MB 45950. In leaves fipronil degraded faster than its metabolites. The residues of fipronil in leaves degraded at the half-life of 9.6 and 18.3 days and that of total fipronil (sum of fipronil and its metabolites) at 13.6 and 20 days, from treatment at recommended and double the recommended dose, respectively. At the time of harvest in leaves, grape berries and soil residues of fipronil and all its metabolites were below the quantifiable limit of 0.01 mg kg^?1.     

基质分散固相萃取和超高效液相色谱-串联质谱法测定水果、蔬菜中的11种杀菌剂

目的 建立水果、蔬菜中11种杀菌剂的基质分散固相萃取-液相色谱-串联质谱分析方法。方法 样品中的杀菌剂经乙腈提取,以PSA、石墨化炭黑和C18为吸附剂的基质分散固相萃取净化,最后用C18柱分离,以乙腈和0.05%甲酸水为流动相,经电喷雾离子源(ESI+)电离,多反应监测(MRM)模式串联质谱检测。结果 腐霉利的检测线性范围为10~500ng/ml,检出限为10μg/kg,其余10种杀菌剂的检测线性范围1.0~50ng/ml,检出限为1μg/kg;11中杀菌剂的平均加标回收率在80.3%~115.6%之间,相对标准偏差在3.9%~11.2%之间。结论 该方法前处理简单、快速、有效、准确灵敏、稳定和安全,适合于水果蔬菜中11种杀菌剂的检测。