气相色谱-质谱法测定烟叶和土壤中丁硫克百威及其代谢产物的残留

建立了气相色谱-质谱法同时检测烟叶和土壤中丁硫克百威及其代谢产物(克百威和3-羟基克百威)残留量的分析方法。土壤样品用丙酮-石油醚[V(丙酮)∶V(石油醚)=1∶4]混合溶液提取,无需净化;鲜烟叶样品用丙酮-乙腈[V(丙酮)∶V(乙腈)=1∶9]混合溶液提取;烤后烟叶用乙腈提取。鲜烟叶和烤后烟叶提取液经旋转蒸发浓缩后,用弗罗里硅土柱净化。结果表明:在0.05~1 mg/kg添加水平下,丁硫克百威及其代谢产物的平均回收率在74%~99%之间,相对标准偏差(RSD,n=5)在1.5%~9.2%之间。该方法的前处理相对于萃取过程较简单,其准确度、精密度和灵敏度均符合农药残留分析与检测的技术要求,适合于丁硫克百威及其代谢产物在烟叶和土壤中的残留分析与检测。     

Sorption and leaching potential of herbicides on Brazilian soils

Sorption of the herbicides alachlor, atrazine, dicamba, hexazinone, imazethapyr, metsulfuron-methyl, nicosulfuron, simazine and sulfometuron-methyl was characterized on six Brazilian soils, using the batch equilibration method. In general, weak acid herbicides (dicamba, imazethapyr, metsulfuron-methyl, nicosulfuron and sulfometuron-methyl) were the least sorbed, whereas weak bases such as triazines and nonionic herbicides (alachlor) were the most sorbed. The Kd values found showed a significant correlation with soil organic carbon content (OC) for all herbicides except imazethapyr and nicosulfuron. Koc values showed a smaller variation among soils than Kd . To estimate the leaching potential, Koc and the ground-water ubiquity score (GUS) were used to calculate half-lives ( t_1/2 ) that would rank these herbicides as leachers or non-leachers. Comparison of calculated values to published values for t_1/2 demonstrated that sulfonylureas and hexazinone are leachers in all soils, alachlor is transitional, and atrazine, simazine and dicamba are leachers or transitional, depending on soil type. Results discussed in this paper provide background to prioritize herbicides or chemical groups that should be evaluated in field conditions with regard to their leaching potential to ground-water in tropical soils.     

超高效液相色谱-串联质谱法测定咖啡鲜果中草铵膦及其代谢产物残留

建立了咖啡鲜果中草铵膦(glufosinate-ammonium)及其代谢产物N-乙酰草铵磷(N-acetylglufosinate)和3-(甲基膦基)丙酸(3-[hydroxy(methyl)phosphinoyl])的超高效液相色谱-串联质谱(UPLC-MS/MS)检测方法。样品经0.1 mol/L的氨水匀浆、超声提取、离心后,取上清液于40℃下减压浓缩,以V(甲醇)∶V(水)=1∶1的混合溶剂定容,经ACQUITY UPLC BEH HILIC色谱柱分离,以乙腈-0.1%甲酸水溶液混合溶剂为流动相梯度洗脱,采用多离子反应监测(MRM)模式扫描,外标法定量。结果表明:在0.1~2.0 mg/L质量浓度范围内,3种化合物的进样浓度与其峰面积之间呈良好线性相关,相关系数(r)分别为0.997、0.998和0.991;在0.05~0.5 mg/kg水平下进行添加回收试验,3种化合物的回收率在92%~107%之间,相对标准偏差(RSD)在2.0%~4.9%之间,定量限(LOQ)均为0.05 mg/kg。该方法简化了样品前处理,提高了回收率,适用于草铵膦的残留检测。     

Degradation and leaching potential of pesticides in biobed systems

Biobeds provide a potential solution to pesticide contamination of surface waters arising from the farmyard. Previous work has shown that biobeds can effectively treat spills and splashes of pesticide. This study investigated the potential for biobeds to treat much larger volumes and amounts of pesticide waste not only arising from spills but also from washing processes. Two systems were assessed using a range of pesticides at the semi-field scale, ie a lined biobed system and an unlined system. Studies using the lined biobeds demonstrated that water management was crucial, with biobeds needing to be covered to exclude rain-water. Once covered, the top of the biobed became hydrophobic, restricting moisture loss and resulting in saturated conditions at depth. The drying out of the top layer coincided with a measured decrease in microbial biomass in the treated biobeds. Applied pesticides were effectively retained within the 0-5 cm layer. Whilst all pesticides tested degraded, low moisture content and microbial activity meant degradation rates were low. Studies using unlined biobeds showed that only the most mobile pesticides leached, and for these > 99% was removed by the system, with a significant proportion degraded within 9 months. Peak concentrations of the two most mobile pesticides did however exceeded the limits that are likely to be required by regulatory bodies. However, it is thought that these limits could be reached by optimisation of the system.     

呋虫胺及其代谢物在水稻生态系统中的残留检测与消解动态

为评价呋虫胺在水稻生态系统中的残留与消解行为,分别在海南、湖南和黑龙江省3地进行了规范残留试验。建立了超高效液相色谱-串联质谱 (UPLC-MS/MS) 检测呋虫胺 (DNF) 及其代谢物1-甲基-3-[(3-四氢呋喃) 甲基]脲 (UF) 与1-甲基-3-[(3-四氢呋喃) 甲基]二氢胍盐 (DN) 在水稻稻株、土壤、田水、糙米和稻壳中残留的分析方法。样品经含体积分数为1%的乙酸水溶液或乙腈溶液提取,QuEChERS方法净化,以甲醇-水混合溶液为流动相梯度洗脱,多反应监测 (MRM) 模式扫描,外标法定量。结果表明:3种分析物的进样浓度与其峰面积之间呈良好线性相关,R2>0.999。DNF、UF和DN在稻株、土壤、田水、糙米和稻壳中的平均回收率在71%~102%之间,在稻株、土壤、田水和糙米中的相对标准偏差 (RSD) 在1.2%~8.3%之间,在稻壳中的RSD在4.4%~20%之间。3种分析物在稻株、土壤、田水、糙米和稻壳中的最低检测浓度 (LOQ) 分别为0.1 mg/kg、0.02 mg/kg、0.01 mg/L、0.02 mg/kg和0.1 mg/kg。DNF、UF和DN的最小检出量分别为1、0.4和4 pg。3种分析物的消解半衰期分别为:DNF在稻株上为0.41~2.7 d,土壤中为1.6~4.2 d,田水中为0.90~2.2 d;DN在稻株上为2.9~13 d,土壤中为64~65 d,田水中为4.2 d;UF在稻株上为0.43~3.1 d。20%呋虫胺悬浮剂以有效成分120~180 g/hm2的剂量于水稻抽穗期施用2~3次,施药间隔期21 d,分别于距末次施药后14 d与21 d采收,呋虫胺在糙米中的残留最大值为0.11 mg/kg,低于中国制定的其在糙米上的最大残留限量标准1 mg/kg。     

Degradation of chlorsulfuron and triasulfuron in alkaline soils under laboratory conditions

The degradation of chlorsulfuron and triasulfuron was investigated in alkaline soils (pH 7.1–9.4) spiked at 40 μg a.i. kg^–1 under laboratory conditions at 25 °C and a moisture content corresponding to 70% field capacity (–33 kPa), using high-performance liquid chromatography. Degradation data for the two herbicides did not follow first-order kinetics, and observed DT₅₀ values in surface soils ranged from 19 to 42 days and from 3 to 24 days for chlorsulfuron and triasulfuron respectively. Disappearance of both chlorsulfuron and triasulfuron was faster in non-sterile than in sterile soil, demonstrating the importance of microbes in the breakdown process. The persistence of chlorsulfuron increased with increasing depth, which can be attributed to the decline in the microbial populations down the profile. The DT₅₀ value for chlorsulfuron at 30–40 cm depth was nearly four times higher than that in the top-soil. The results obtained show that persistence of these herbicides in alkaline surface soils at 25 °C and at a moisture content of 70% field capacity is similar to those reported in other European and North American soils. The study shows that if these herbicides are contained in surface soil layers, the risk of residue carry-over under southern Australian conditions is small. However, the rate of their degradation in alkaline subsoils is very slow, and under conditions conducive to leaching their prolonged persistence in the soil profile is possible.     

土壤中苯肽胺酸的测定及淋溶特性研究

建立了反相条件下超高效液相色谱-串联质谱(UPLC-MS/MS)检测土壤中苯肽胺酸残留量的分析方法,并结合土壤薄层层析试验研究了苯肽胺酸在3种典型土壤(黑土、水稻土和红土)中的淋溶特性。结果表明:添加水平为0.1、1和10 mg/kg时,苯肽胺酸在土壤中的添加回收率为77.3%~99.4%,相对标准偏差(RSD)为1.3%~11.4%;其在3种土壤中的检出限(LOD)均低于1.0μg/kg。苯肽胺酸在吉林黑土中的比移值(Rf)为0.83,其移动性为可移动;在江苏水稻土中的Rf值为0.61,在湖南红土中的Rf值为0.62,移动性均为中等。     

液相色谱-串联质谱同时检测水稻样品中乙基多杀菌素及其代谢物残留

采用液相色谱-串联质谱(LC-MS/MS)技术建立了同时检测水稻植株、谷壳、糙米中乙基多杀菌素及其代谢物N-demethyl-175-J和N-formyl-175-J残留的分析方法。样品采用乙腈提取,经分散固相萃取(PSA)净化,LC-MS/MS检测。结果表明:在0.02、0.2和2 mg/kg添加水平下,乙基多杀菌素及其代谢物的平均回收率在73%~105%之间,相对标准偏差(RSD)在0.9%~10%之间。乙基多杀菌素-J和-L的定量限(LOQ)分别0.016和0.004 mg/kg,代谢物的定量限(LOQ)为0.02 mg/kg。该方法操作简便、稳定和快速,可以满足水稻样品中乙基多杀菌素及其代谢物的定性与定量分析要求。     

液相色谱-串联质谱法同时测定菠菜、土壤及水体中螺虫乙酯及4种代谢物残留

采用QuEChERS及固相萃取样品前处理方法,结合液相色谱-三重四极杆串联质谱技术（LC-MS/MS）,以负离子扫描和多反应监测模式（MRM）,建立了菠菜、土壤及水体中螺虫乙酯及4种代谢物（B-enol、B-keto、B-mono和B-glu）残留的检测方法。通过对质谱检测条件的优化表明,以乙腈-0.5%甲酸水溶液作为流动相,采用梯度洗脱时,色谱分离度及灵敏度最好。通过对样品前处理条件的考察,发现选用0.1%甲酸-乙腈溶液作为提取溶剂,经50 mg的m（PSA）:m（GCB）=1:1净化处理后,在0.05、0.5和1 mg/kg添加水平下,螺虫乙酯及4种代谢物在菠菜中的回收率为81%~103%,相对标准偏差（RSD）为1.7%~7.9%;在土壤样品中的回收率为82%~98%,RSD为1.9%~7.6%。采用NH2柱作为固相萃取柱,用10 mL二氯甲烷洗脱,在0.005、0.05和0.5 mg/L添加水平下,螺虫乙酯及4种代谢物在水体中的回收率为82%~95%,RSD为1.5%~6.2%。在0.002~1 mg/L范围内,螺虫乙酯及4种代谢物的质量浓度与对应的峰面积间呈现良好的线性关系,r在0.996 7~0.999 7之间。检出限（S/N=3）分别为螺虫乙酯（0.000 2~0.000 3 mg/kg）,B-enol（0.000 1~0.000 3 mg/kg）,B-keto（0.000 4~0.000 6 mg/kg）,B-mono（0.000 4~0.000 7 mg/kg）,B-glu（0.000 2~0.000 6 mg/kg）;定量限（S/N=10）分别为螺虫乙酯（0.000 6~0.001 mg/kg）,B-enol（0.000 3~0.001 mg/kg）,B-keto（0.001 2~0.001 6 mg/kg）,B-mono（0.001 2~0.001 9 mg/kg）,B-glu（0.000 6~0.001 3 mg/kg）。方法分析结果符合农药残留检测要求,适用于菠菜、土壤及水体中螺虫乙酯及4种代谢物残留的同时检测。     

Sorption-desorption of flucarbazone and propoxycarbazone and their benzenesulfonamide and triazolinone metabolites in two soils

Sorption-desorption interactions of pesticides with soil determine the availability of pesticides in soil for transport, plant uptake and microbial degradation. These interactions are affected by the physical and chemical properties of the pesticide and soil and, for some pesticides, their residence time in the soil. While sorption-desorption of many herbicides has been characterised, very little work in this area has been done on herbicide metabolites. The objective of this study was to characterise sorption-desorption of two sulfonylaminocarbonyltriazolinone herbicides, flucarbazone and propoxycarbazone, and their benzenesulfonamide and triazolinone metabolites in two soils with different physical and chemical properties. K(f) values for all four chemicals were greater in clay loam soil, which had higher organic carbon and clay contents than loamy sand. K(f-oc) ranged from 29 to 119 for the herbicides and from 42 to 84 for the metabolites. Desorption was hysteretic in every case. Lower desorption in the more sorptive system might indicate that hysteresis can be attributed to irreversible binding of the molecules to soil surfaces. These data show the importance of characterisation of both sorption and desorption of herbicide residues in soil, particularly in the case of prediction of herbicide residue transport. In this case, potential transport of sulfonylaminocarbonyltriazolinone herbicide metabolites would be overpredicted if parent chemical soil sorption values were used to predict transport.     

茚嗪氟草胺及其代谢物在柑橘和土壤中的残留及消解动态

为明确茚嗪氟草胺及其代谢物indaziflam-diaminotriazine(IND-D),indaziflam-carboxylic acid(IND-C),indaziflam-triazine-indanone(IND-T),indaziflam-hydroxyethyl(IND-H),indaziflam-o...     

超高效液相色谱-串联质谱法测定柑橘中的草甘膦及其代谢物残留

本研究首次建立了一种超高效液相色谱-串联质谱法(UHPLC-MS/MS)同时测定柑橘中草甘膦及其代谢物N-乙酰草甘膦?氨甲基磷酸(AMPA)和N-乙酰AMPA?样品经过0.5%甲酸水提取, 以十八烷基硅烷键合硅胶柱(C18)净化, 利用水和200 mmol/L碳酸氢铵溶液(含0.1%氨水)作为流动相梯度洗脱, 在多反应监测模式下定量分析?结果表明, 草甘膦及其代谢物在0.05~1 mg/kg范围内线性关系良好, 相关系数均大于0.99; 草甘膦及其3个代谢物在柑橘全果和果肉基质中3个加标水平下回收率为 70.5%~109.5%, 相对标准偏差(RSD)为0.6%~10.1%, 定量限为0.05 mg/kg?本方法的前处理样品无需衍生, 简便?快捷?高效?准确可靠, 可用于柑橘中草甘膦及其代谢物N-乙酰草甘膦?AMPA和N-乙酰AMPA的定量检测?     

Residual activity of clomeprop and its downward movement under laboratory conditions

The relationship between the behavior of clomeprop ([ RS ]-2-[2,4-dichloro- m -tolyloxy]propionanilide) and its residual phytotoxic activity in the soil was investigated in the laboratory with special emphasis on the concentration in the soil water. The phytotoxic activity of clomeprop on radish seedlings ( Raphanus sativus L. var. radicula cv. Akamaruhatsukadaikon), as the test plant, became greater with time after application but the inhibition was different between the two soils, which had different properties. The amount of 2-(2,4-dichloro-3-methylphenoxy)propionic acid (DMPA), a hydrolyzed and active metabolite of clomeprop, in the soil water and total soil increased with time, corresponding to the decrease in the amount of clomeprop under non-water leakage conditions. The residual phytotoxic activity of clomeprop in the soil was more highly correlated with the concentration of DMPA in the soil water than with the amount of DMPA in the total soil. In addition, a leaching column test was conducted with clomeprop and DMPA. The DMPA easily moved downward and the concentration in the soil water in the upper layer decreased with time after application. It is supposed that the downward movement of DMPA was one of the factors influencing the lasting effect of clomeprop in the field.     

异噁唑草酮在土壤表面光解及在土壤中的降解和淋溶特性

为合理评估除草剂异唑草酮的环境风险,在实验室模拟条件下,研究了异唑草酮在土壤 (红壤土)表面光解以及在不同质地土壤 (潮土、水稻土和红壤土) 中的降解和淋溶特性。结果表明:异唑草酮在土壤表面的光解遵循一级反应动力学方程c_t = 4.23e–0.008t (r = 0.937),半衰期为82.5 h;其在潮土、水稻土和红壤土中的降解均符合一级动力学方程,好氧条件下,异唑草酮在3种土壤中的降解半衰期分别为10.5、43.3和139 h,厌氧条件下的降解半衰期分别为19.4、18.4和158 h;其在潮土、水稻土和红壤土中的淋溶系数 (R_f) 分别为0.417 0、0.083 3和0.083 3。研究表明:异唑草酮在土壤表面光解速率较慢,而在土壤中好氧及厌氧条件下降解速率均较快,残留期短;其在土壤中淋溶性较弱,不易对周围环境及地下水造成污染风险。     

超高效液相色谱-串联质谱法测定土壤中硝磺草酮及其代谢物残留

建立了土壤中硝磺草酮及其代谢物4-甲砜基-2-硝基苯甲酸(MNBA)和2-氨基-4-甲砜基苯甲酸(AMBA)残留的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。样品用0.1%氨水-乙腈溶液提取后,经Cleanert PAX固相萃取柱净化,以乙腈和0.3%甲酸水为流动相,Acquity HSS T3色谱柱梯度洗脱,电喷雾负离子多反应监测模式UPLC-MS/MS检测。结果表明:在0.3~50μg/kg添加水平下,硝磺草酮、MNBA和AMBA的平均添加回收率在73%~97%之间,相对标准偏差在2.4%~12.9%之间,该方法的检出限分别为0.1、0.3和0.2μg/kg,定量限分别为0.3、1.0和0.6μg/kg。应用该方法对室内模拟试验的红土样品进行了分析,结果表明,硝磺草酮在红土中的消解半衰期为4.0d,土壤中降解产物AMBA残留量高于MNBA。     

螺虫乙酯及其代谢物在梨和土壤中的残留及消解动态

为建立梨和土壤中螺虫乙酯及其代谢物螺虫乙酯-烯醇-糖苷 (S-glu)、螺虫乙酯-酮-羟基 (S-keto)、螺虫乙酯-烯醇 (S-enol) 和螺虫乙酯-单羟基 (S-mono) 的残留分析方法,以及明确螺虫乙酯在梨中的残留规律,采用体积分数为1%的乙酸乙腈为提取剂,以N-丙基乙二胺 (PSA) 和无水硫酸镁为分散净化剂的QuEChERS方法,利用超高效液相色谱-串联质谱 (UPLC-MS/MS) 在选择反应监测模式 (SRM) 下检测,外标法定量。结果显示:螺虫乙酯在0.0005~0.1 mg/L范围内,S-glu在0.005~0.5 mg/L范围内,S-keto、S-enol和S-mono在0.0005~0.5 mg/L范围内各化合物的质量浓度与质谱峰面积间均具有良好的线性关系 (R2 ≥ 0.999);在0.005~0.7 mg/kg添加水平下,螺虫乙酯及其代谢物在梨果中的平均回收率为84%~109%,相对标准偏差 (RSD) 为1.2%~3.3%;在土壤中平均回收率为86%~102%,RSD为1.1%~3.6%。最低检测浓度 (LOQ)为5 μg/kg。该方法检测速度快、灵敏度高、重现性好,适用于梨和土壤中螺虫乙酯及其代谢物残留的快速检测和确证。按推荐剂量进行田间施药,当梨果成熟采收时,螺虫乙酯及其代谢物在梨中的残留量之和在0.023~0.056 mg/kg之间,低于中国规定的最大残留限量标准 (0.7 mg/kg);在土壤中的残留量在0~0.015 mg/kg之间。螺虫乙酯及其代谢物在梨果和土壤中的消解动态均符合一级反应动力学方程,半衰期分别为为12.4 d和7.1 d。田间残留试验结果表明,螺虫乙酯用于梨树害虫防治是安全的。     

气相色谱-串联质谱法测定西瓜和黄瓜中吡唑萘菌胺及其代谢物残留

基于分散固相萃取与气相色谱-串联质谱建立了快速检测西瓜和黄瓜中吡唑萘菌胺及其代谢物残留的分析方法。样品经乙腈提取,N-丙基乙二胺 (PSA) 和C₁₈净化,气相色谱-串联质谱 (GC-MS/MS) 测定,多反应检测模式 (MRM) 分析,内标法定量。考察了提取溶剂及吸附剂种类对分析结果的影响,优化了气相色谱-质谱条件。结果表明:在1~500 μg/L范围内,吡唑萘菌胺及其代谢物的质量浓度与对应的峰面积间均呈良好的线性关系,相关系数 (r) 为0.994 3~0.999 9。在0.01、0.1和1 mg/kg 3个添加水平下,吡唑萘菌胺及其代谢物在西瓜中的平均回收率为70%~105%,相对标准偏差 (RSD,n = 5) 为3.4%~13%;在黄瓜中的添加回收率为82%~104%,相对标准偏差 (RSD,n = 5) 为1.3%~9.3%。吡唑萘菌胺及其代谢物的定量限 (LOQ,S/N = 10) 为0.3~0.6 μg/kg,检出限 (LOD,S/N = 3) 为0.1~0.2 ng。该方法简单、高效、快速,满足残留分析的要求,适用于西瓜、黄瓜中吡唑萘菌胺及其代谢物残留的快速检测。     

超高效液相色谱串联质谱法测定溴虫氟苯双酰胺及其两种代谢物在辣椒上的残留

本研究建立并优化了基于超高效液相色谱串联质谱(UHPLC-MS/MS)同时测定辣椒中溴虫氟苯双酰胺及其代谢物DM-8007和S(PFP-OH)-8007的残留分析方法。样品经过乙腈提取,无水硫酸镁、N-丙基乙二胺(PSA)及石墨化炭黑(GCB)净化。净化样品以甲醇和0.2%甲酸水为流动相,采用C18色谱柱进行分离,并通过电喷雾正离子(ESI⁺)扫描,多反应监测(MRM)模式进行定量分析。结果表明,溴虫氟苯双酰胺及其两种代谢物在0.01～1 mg/kg范围内与目标化合物的峰面积线性关系良好,相关系数均大于0.99;在空白辣椒基质中添加溴虫氟苯双酰胺及其两种代谢物,在3个加标水平下回收率为90.8%～97.4%,相对标准偏差(RSD)为1.3%～5.7%,定量限(LOQ)为0.01 mg/kg,满足残留分析的要求。采用该方法监测了5%溴虫氟苯双酰胺悬浮剂在湖南、河南、浙江3个地点的消解动态,溴虫氟苯双酰胺在辣椒样品中的消解动态规律符合一级反应动力学方程,在3个地点的半衰期分别为7.7、4.7 d和2.8 d。     

基质分散固相萃取-QuEChERS耦合HPLC法测定棉花叶片中吡虫啉及其相关代谢物

建立了QuEChERS前处理的棉花叶片中吡虫啉及其代谢物含量的高效液相色谱(HPLC)分析方法。在QuEChERS前处理方法的基础上,确定了乙腈作为提取剂,盐析材料为1.00 g氯化钠、4.00 g无水硫酸镁、0.50 g柠檬酸二钠和1.00 g柠檬酸钠,净化材料为25 mg的N-丙基乙二胺(PSA),在2%乙腈-甲醇∶水=3∶7条件下HPLC法进行定量测定。结果表明:棉花叶片中的吡虫啉及其4种代谢物吡虫啉脲、烯式吡虫啉、吡虫啉胍和6-氯烟酸的平均加标回收率为92.84%～110.90%,相对标准偏差(RSD)在0.15%～6.99%之间,检出限(LOD)分别为0.0044、0.042、0.0011、0.091 mg·kg^-1和0.0066 mg·kg^-1,定量限(LOQ)分别为0.015、0.19、0.0059、0.036 mg·kg^-1和0.028 mg·kg^-1。该分析方法前处理简便、快速、准确,可为棉花叶片中吡虫啉及其代谢物残留的测定提供参考。