动物性食品中硝基咪唑类兽药多残留酶联免疫检测方法的建立

本试验采用活化酯法,将合成的具有2-甲基-5-硝基咪唑通用结构的半抗原与载体蛋白偶联制备免疫抗原和包被抗原,以获得的抗原制备2-甲基-5-硝基咪唑通用结构抗体,并建立5种硝基咪唑类药物及代谢物的酶联免疫分析技术。结果表明:制备的抗体效价高于1∶100 000,该方法在不同动物源性食品中的加标回收率在85.65%~108.65%之间,检测限达1.9×10-4mg·L-1,对2-甲基-5-硝基咪唑、甲硝唑、替硝唑、地美硝唑和塞克哒唑5种硝基咪唑抗生素及代谢物交叉反应率达95%以上。本研究为进一步建立和完善酶联免疫法检测动物性食品中硝基咪唑类药物残留提供了技术支撑。     

UPLC-MS/MS同时测定水产品中硝基呋喃类药物代谢物、孔雀石绿类化合物和氯霉素

研究建立同时测定水产品中硝基呋喃类药物代谢物、孔雀石绿类和氯霉素等9种化合物的方法。向试样加入邻硝基苯甲醛,在酸性条件下衍生,利用乙腈提取,EMR-Lipid净化,用ACQUITY UPLC HSS T3色谱柱洗脱分离,采用超高效液相色谱-串联质谱法(UPLC-MS/MS),正和负离子MRM模式采集检测。结果显示,9种化合物在相应范围内线性良好,相关系数均0.99,定量限为0.01～0.50μg/kg。4种水产品在添加量为1、 4和10μg/kg的加标回收和精密度试验中,回收率为79.7%～127.1%,相对标准偏差(RSD)为0.9%～17.1%。结果表明,该方法简单、高效,可以同时前处理并快速准确测定水产品中9种禁用兽药残留。     

超高效液相色谱-串联质谱法测定动物尿液中5种镇静剂类药物残留

为建立动物尿液中异丙嗪亚砜、异丙嗪、氯丙嗪、安眠酮和地西泮5种镇静剂类药物残留的超高效液相色谱-串联质谱(UPLC-MS/MS)检测方法,本研究以固相萃取为净化手段,采用HPLC-MS/MS检测猪、牛和羊尿液中5种镇静剂类药物的残留量。结果表明,尿液样品经离心,调节pH值,Oasis MCX固相萃取柱净化后,能够有效去除杂质,5种镇静剂在0.6~20.0 μg·L^-1范围内呈良好的线性关系,相关系数(R²)均大于0.993;5种镇静剂类药物的检出限和定量限分别为0.1和0.6 μg·L^-1,0.6、2.5和9.0 μg·L^-1 3个添加水平的回收率介于64.6%~110.2%之间,相对标准偏差(RSD)均小于6.0%。本研究结果为不同动物尿液中镇静剂类兽药残留的精准检测提供了技术支持。     

磁性石墨烯固相萃取-液相色谱串联质谱法测定有机肥料中镇静剂类和β-受体激素类药物残留

采用磁性石墨烯固相萃取结合超高效液相色谱串联质谱技术,建立了有机肥料中8种镇静剂类和15种β-受体激素药物残留的分析检测方法。样品采用0.1%甲酸乙腈提取,通过磁性石墨烯粉固相萃取吸附目标物,除去杂质,然后再解吸目标物。经Agilent ZORBAX Eclipse Plus C18 (3.0 mm×100 mm,1.8 μm)色谱柱分离,串联质谱进行检测,标准曲线内标法定量。结果表明:23种目标物在0.5～10.0 μg/L范围内线性关系良好(R2>0.999)。在有机肥料样品基质中,目标化合物2、5、10 μg/kg 3个加标水平的平均回收率在75.1%～102.4%之间,相对标准偏差为4.3%～14.3%(n=6)。该方法净化效率高、适用范围广,可用于有机肥料中镇静剂类和β-受体激素类药物残留筛查和检测。     

QuEChERS-四极杆飞行时间高分辨质谱法快速筛查典型水产品中的喹诺酮类药物残留

以Qu ECh ERS样品预处理方法、四极杆飞行时间高分辨质谱(Q-TOF MS)为检测手段,建立了典型水产品中的15种喹诺酮类药物残留的快速筛查方法。样品采取5%甲酸乙腈提取,PSA和C_(18)净化,Q-TOF质谱正离子模式扫描定量,自建数据库定性。15种喹诺酮类残留药物检出限为0.5~1.5μg/kg,方法平均回收率在72.3%~102.1%,相对标准偏差在3.8%~13.2%。该方法快速、简便、准确,适用于典型水产品中喹诺酮类药物的快速筛查。     

串联两种免疫亲和柱同时检测粮食中赭曲霉毒素A和玉米赤霉烯酮

建立了一种通过串联两种免疫亲和柱的方式同时检测粮食中赭曲霉毒素A和玉米赤霉烯酮的方法。样品经乙腈∶水(90∶10)提取后,通过串联的两种免疫亲和柱净化,以高效液相色谱荧光检测器检测。结果表明,赭曲霉毒素A和玉米赤霉烯酮线性范围分别为1~30μg/mL和10~300μg/mL,相关系数R2分别为0.999 02和0.995 72,不同基质样品的回收率分别为75.25%~98.37%和83.41%~117.09%,精密度分别为1.28%~8.16%和1.23%~9.45%,最低检出限分别为0.4μg/kg和3.9μg/kg。本方法具有操作简便、快捷和准确性高等特点,适用于粮食中赭曲霉毒素A和玉米赤霉烯酮的同时检测。     

超高效液相色谱-串联质谱法测定牛奶和奶粉中五种苯并咪唑类药物

为建立牛奶及奶粉中5种苯并咪唑类药物(阿苯达唑、芬苯达唑、奥芬达唑、噻苯达唑、苯硫氨酯)简便、准确的分析检测方法,以固相萃取为净化手段,采用Acquity UPLC^® BEH C₁₈(100 mm×2.1 mm,1.7 μm)色谱柱进行分离,电喷雾离子源(ESI⁺),多反应监测(MRM)模式检测。结果表明,5种苯并咪唑类药物在1~500 μg·L^-1范围内呈线性相关,相关系数(r)均大于0.996,加标平均回收率介于91.7%~97.8%之间,相对标准偏差(RSD)在1.4%~6.5%之间,基质效应均小于15%。5种药物的检出限均在0.1~3 μg·kg^-1范围内,定量限均在0.5~10 μg·kg^-1范围内。该方法操作简单、快速且灵敏度高,重现性好,能够用于牛奶及奶粉5种苯并咪唑类药物的同时测定。     

高效液相色谱-串联质谱测定水溶性肥料中8种植物生长调节剂

采用高效液相色谱-串联质谱法(HPLC-MS／MS)，同时检测水溶性肥料中8种植物生长调节剂（胺鲜酯、甜菜碱、矮壮素、阿维菌素、氯吡脲、复硝酚钠、萘乙酸钠和赤霉素）。样品用高效液相色谱-串联质谱法检测，标准曲线外标法定量。采用多反应监测模式，正离子模式下扫描胺鲜酯、甜菜碱、矮壮素、阿维菌素和氯吡脲，负离子模式下扫描复硝酚钠、萘乙酸钠和赤霉素。在3个添加水平下，样品平均回收率为91.7%～102.2%，相对标准偏差为1.5％～7.5％；胺鲜酯、甜菜碱、矮壮素、阿维菌素、氯吡脲、4-硝基苯酚钠和5-硝基愈创木酚钠的检出限均为2 mg/kg，萘乙酸钠的检出限为2.5 mg/kg，2-硝基苯酚钠和赤霉素的检出限为20 mg/kg。本方法简便、快速、安全，重现性良好，可用于水溶性肥料样品中植物生长调节剂的快速检测。     

超高效液相色谱-串联质谱法测定蔬菜中15种全氟化合物

建立了蔬菜中15种全氟化合物的超高效液相色谱-串联质谱分析方法。采用离子对液液萃取法提取蔬菜样品中全氟化合物。向冷冻干燥后的样品中加入Na2CO3/Na HCO3缓冲液和四丁基硫酸氢铵TBAHs溶液,经过甲基叔丁基醚MTBE溶液两次震荡提取,再加入石墨化炭黑Carbon-GCB粉末净化,氮气浓缩,甲醇定容。甲醇-水(均加入醋酸铵)溶液作为流动相进行梯度洗脱,采用ACQUITY UPLC BEH Shield RP 18色谱柱分离,质谱(ESI-)采用多离子检测模式(MRM)检测,内标法进行定量分析。本方法在12 min内完成15种全氟化合物的分离分析。15种全氟化合物在0.5~100μg/L浓度范围内线性关系系数r0.995 5,检出限为0.001~0.029μg/kg,定量限为0.003~0.096μg/kg。在添加浓度1.0、5.0和10.0μg/kg水平下,15种全氟化合物在黄瓜、番茄、油菜中的添加回收率为71.65%~122.57%,相对标准偏差均小于19.7%。该方法样品处理简单,选择性好,且灵敏、准确,可用于蔬菜中全氟化合物的检测。     

QuEChERS分散萃取—气相色谱法测定有机肥料中23种有机磷药物残留

采用QuEChERS分散萃取结合气相色谱技术,建立了有机肥料中23种有机磷类药物残留的分析检测方法。样品采用含有0.1%冰醋酸的乙腈提取,目标物QuEChERS分散萃取粉净化,除去杂质后,经气相色谱检测,标准曲线外标法定量。结果表明:23种目标物在0.05～0.5 μg/mL范围内线性关系良好,相关系数为0.9990～0.9998。在有机肥料样品基质中,目标化合物在0.01、0.02、0.10 mg/kg 3个加标水平的平均回收率在80.9%～114.6%之间,相对标准偏差为1.4%～9.5%(n=6),基质效应因子为0.82～1.36。该方法净化效果好、操作简单、适用范围广,可用于有机肥料中多种有机磷类药物残留的定量测定。     

Rapid and selective method for quantitation of metronidazole in pharmaceuticals

A selective and highly sensitive assay for N-1-substituted nitroimidazoles has been modified and adapted for rapid estimation of metronidazole in pharmaceuticals. The color reaction is based on diazotization of sulfanilamide with the nitrite ions liberated by alkaline hydrolysis of metronidazole and subsequent coupling of the diazonium salt with N-1-(naphthyl)-ethylenediamine dihydrochloride. This method is applicable for the assay of benzoyl metronidazole in oral suspension. Officially recommended excipients and preservatives do not interfere.     

Determination of triterpene glycosides in sea cucumber (Stichopus japonicus) and its related products by high-performance liquid chromatography

A creative and sensitive method has been developed for the determination of triterpene glycosides concentrations in sea cucumber ( Stichopus japonicus) and related products by using d-quinovose (6-deoxyglucose) as the measurement standard by reverse-phase high-performance liquid chromatography (HPLC) and variable-wavelength detection. d-quinovose, which is a unique monosaccharide in holostane triterpene glycosides, was liberated by acid hydrolysis and precolumn derivatized by 1-phenyl-3-methyl-5-pyrazolone (PMP). PMP-quinovose was analyzed by HPLC with 22% acetonitrile in 0.05 M KH2PO4 aquatic solution (pH 5.2) as mobile phase. The calibration curves of d-quinovose were linear within the range of 6.56-164 mg/L (r(2) > 0.995). The contents of triterpene glycosides in various S. japonicus products were determined after appropriate pretreatment methods. The concentration of triterpene glycosides was calculated by the formula C = C(qui) x alpha (alpha = 8.5). The result showed that this method was a simple, rapid, and stable method for the determination of triterpene glycosides in S. japonicus products.     

小型活体水产运输箱电解水增氧装置设计与试验

水产长距离运输保证鲜活需要保持水产原生存环境的压力、水质、溶氧度等条件,其中溶氧度直接关系水产的存活,因此增氧装置的设计成为活体水产运输的关键技术之一。为了解决电解水增氧方式能耗大、难以小型化的问题,该研究设计了适用于小型水产运输箱的电解水增氧装置。首先根据计算流体力学软件仿真计算结果设计了装置中可在正负电极间产生恒稳均匀流场的整流结构参数;然后通过试验探索水溶氧规律和装置总能耗在电解电压与水交换流量影响下的关系。试验结果表明在容积为8×10-3 m3的箱体内,采用直流电解,当电解电压为37 V、水交换流量为6.97×10-5 m3/s时,总能耗最低为39.39 kJ。本文的装置设计和试验结果可为电解水增氧方法在水产运输和养殖中的实际应用提供了依据。     

气相色谱法测定水产品中三氯杀螨醇残留量

为拓展食品中农药残留监控范围,本文建立了水产品中三氯杀螨醇的气相色谱测定方法。试验基质为鳗鲡、罗非鱼、对虾、玻纹巴菲蛤,取其可食用组织的均匀试样1g,用正己烷超声萃取,用浓硫酸和弗罗里硅土净化,二氯甲烷／正己烷混合液淋洗层析柱。洗脱液收集和旋转蒸发浓缩后,用气相色谱法测定其中的三氯杀螨醇,外标法定量。测定仪器为HP6890N型气相色谱仪,配HP7683B型自动进样器、HP-5型毛细管气相色谱柱（30m×0．32mm×0．25μm）和。Ni微电子捕获检测器。三氯杀螨醇浓度线性范围是0．0025-0．4μg·mL-1（r=0．9998,P〈0．001）,方法定量检测下限为0．01μg·g-1。用未检出三氯杀螨醇的鳗鲡等4种试样,添加3个水平的三氯杀螨醇,分别为0．01、0．10、O．50μg·g-1,每种试样每个添加量测定6份。结果显示,加标回收率在71％-111％范围内,批内变异系数为3．2％～8．5％（n=6）,批间变异系数为2．5％～7．1％（n=4）。定量限点加标试样的回收率为73％～94％,批内变异系数为5．9％-7．7％,峰高信噪比〉10。本方法试样用量少,前处理简便,可操作性强,适合测定水产品可食部分的三氯杀螨醇残留量。     

Permanganate oxidation of methylated and non-methylated aquatic humus in Norway

The chemical composition of aquatic humus was investigated by permanganate oxidation. Both methylated and non-methylated samples were investigated and the results compared with those of different soil humic fractions investigated earlier.The total amount of oxidation products identified from the methylated sample was 2%, and from the non-methylated sample 0.9%. The composition of the oxidation products from methylated aquatic humus was 42% benzenecarboxylic acid methyl esters (8 different compounds), 43% methoxy-benzenecarboxylic acid methyl esters (12 compounds), 10% dimethoxy-benzenecarboxylic acid methyl esters (4 compounds), and 5% of 1, 2, 3-propanetricarboxylic acid trimethyl ester. The unmethylated aquatic humus yielded 84% benzenecarboxylic acid methyl ester (7 compounds), 7% methoxy-benzenecarboxylic acid methyl esters (2 compounds), and 9% of 1, 2, 3-propanetricarboxylic acid trimethyl ester. Three diazines isolated from methylated material were believed to be artefacts from diazomethane treatment. Two of the diazines have earlier been found by oxidation of methylated soil samples, the third, C₁₀H₁₂N₂O₆, is an oxidation product of methylated aquatic humus only.Oxidation of aquatic humus yielded more benzenecarboxylic acids and methoxy-benzenecarboxylic acids than soil humic fractions, and less dimethoxy-benzenecarboxylic acids. No aliphatic dicarboxylic acids were detected among the oxidation products of the aquatic humus.The compounds identified are mainly the same as those found by oxidation of different soil humic fractions, although their yields clearly demonstrated that the aquatic humus differed in composition from the soil fractions.     

Colorimetric determination of diazepam in pharmaceutical preparations.

A colorimetric method is presented for the estimation of diazepam as the pure drug and in formulations. Diazepam is hydrolyzed with 6N HCl to 2-methylamino-5-chlorobenzophenone, which is extracted with chloroform to give a yellow solution whose absorbance is measured at 410 nm against a solvent blank. The color obeys Beer's law in the concentration range of 0-30 mug/ml. In 5 determinations, recovery was 99.0 +/- 1.9%. The method is applicable to pure diazepam and its formulations for oral and parenteral use. No interferences were observed from pyridoxine hydrochloride and commonly used preservatives, vehicles, and colors.     

Degradation of [(14)C]carfentrazone-ethyl under aerobic aquatic conditions.

Carfentrazone-ethyl (CF-E) is an aryl triazolinone reduced-risk herbicide for use on corn, wheat, and soybean. As part of the assessment of its metabolic fate, the aerobic aquatic metabolism of [(14)C]CF-E at a concentration of 0.22 microg/g was investigated. Two separate aquatic sediments (silty clay loam and clay loam soils, flooded with water) were used in the study. At each of eight samplings throughout the 30-day study, the distribution of radioactivity between surface water, sediment, and volatile fractions was assessed. At zero time, the majority of the applied radioactivity was contained in the water layer (83-90%), declining to 70-80% after 30 days. This was coupled with an increase in the percent radioactivity in the soil layer from 4-6% at day 0 to 13-19% after 30 days. Nonextractable soil residues and volatile degradation products were formed in negligible amounts. Analysis of the incubation extracts from either aquatic sediment indicated a rapid conversion (<2 days) of the parent CF-E ester to carfentrazone-chloropropionic acid. Over time, increasing amounts of a cascade of acidic degradation products comprising >90% of the applied radioactivity were formed. Identification of these degradation products was initially achieved through chromatographic comparison with reference synthetic standards and subsequently confirmed using LC-MS analysis. A degradation pathway for CF-E under aerobic aquatic conditions is proposed.     

漂浮栽培水生植物对入滇河流污水中磷的去除效果研究

利用水生植物净化富营养化水体是污染水体生物治理的途径之一,为了找出适宜在水体中生长并对磷的去除效果较好的植物,选择5个品种的水稻以及空心菜、茭白和水花生为供试水生植物,通过静态水培试验,研究了各植物在富营养化水体中的生长状况,以及对水体中磷的去除效果。结果表明,在不添加任何植物营养的条件下,植物在富营养化水体中均能正常生长;有植物处理系统对水体中总磷（TP）、水溶性总磷（DTP）的去除效果显著高于无植物对照;有植物处理系统TP的去除率为53.28%～84.07%,DTP的去除率为44.99%～88.81%;无植物对照TP的去除率为32.57%,DTP的去除率为37.51%。植物组织所累积的磷占各自系统去除量的21.54%～75.32%,植物的吸收作用是磷去除的主要途径。水稻功米1号的经济产量最高,为616.28 g.m-2,组织所累积的磷占系统去除量也是最大,为75.32%。在所有供试植物中,水稻功米1号对富营养化水体既有较好的净化效果,又能获得一定的经济产量,是最优的净化植物,同时也是最适宜在水体中生长的水稻品种。     

Development of a gas-liquid chromatographic method for the analysis of fatty acid tryptamides in cocoa products

The determination of the occurrence and level of cocoa shells in cocoa products and chocolate is an important analytical issue. The recent European Union directive on cocoa and chocolate products (2000/36/EC) has not retained the former limit of a maximum amount of 5% of cocoa shells in cocoa nibs (based on fat-free dry matter), previously authorized for the elaboration of cocoa products such as cocoa mass. In the present study, we report a reliable gas-liquid chromatography procedure suitable for the determination of the occurrence of cocoa shells in cocoa products by detection of fatty acid tryptamides (FATs). The precision of the method was evaluated by analyzing nine different samples (cocoa liquors with different ranges of shells) six times (replicate repeatability). The variations of the robust coefficient of variation of the repeatability demonstrated that FAT(C22), FAT(C24), and total FATs are good markers for the detection of shells in cocoa products. The trueness of the method was evaluated by determining the FAT content in two spiked matrices (cocoa liquors and cocoa shells) at different levels (from 1 to 50 mg/100 g). A good relation was found between the results obtained and the spiking (recovery varied between 90 and 130%), and the linearity range was established between 1 and 50 mg/100 g in cocoa products. For total FAT contents of cocoa liquor containing 5% shells, the measurement uncertainty allows us to conclude that FAT is equal to 4.01 +/- 0.8 mg/100 g. This validated method is perfectly suitable to determine shell contents in cocoa products using FAT(C22), FAT(C24), and total FATs as markers. The results also confirmed that cocoa shells contain FAT(C24) and FAT(C22) in a constant ratio of nearly 2:1.     

生物传感器在水产品新鲜度检测中的应用与研究进展

新鲜度是判断水产品品质的一项重要指标。传统新鲜度检测方法大多繁琐、费时费力,建立快速便捷的检测方法具有重要的现实意义和学术价值。生物传感器操作简单、检测快速、成本低,近年来被广泛研究应用于水产品新鲜度的检测。本文在简要阐述传统和新型新鲜度检测方法的基础上,综述了生物传感器在水产品新鲜度检测上的应用,着重介绍了酶固定载体和纳米传感器方面的最新进展,并概述用于水产品新鲜度检测的生物传感器技术当前存在的问题及发展趋势,旨在为该光传感器的后续研发提供参考。