离子液体双水相萃取-HPLC分析红酒中的痕量氯酚类物质

建立亲水性离子液体[C_4MIM]BF_4与无机盐(NH_4)_2SO_4形成的离子液体双水相萃取富集红酒样品中6种痕量氯酚类物质的方法。通过考察离子液体和盐的种类、pH值、离子液体和盐质量分数对氯酚萃取率和富集倍数的影响,确定萃取氯酚的最优条件。在最佳萃取条件下,6种氯酚的线性范围为20~200μg/L,相关系数(R~2)达到0.999,6种氯酚的检出限在3.68~12.16μg/L之间。对实际红酒样品进行测定,加标回收率为87.73%~103.44%,相对标准偏差在0.33%~6.35%之间。该法操作简单、迅速、绿色且具有较高的萃取效率。     

离子液体分散液液微萃取氨基甲酸酯类农药

建立一种快速简便的超声辅助离子液体-分散液液微萃取(UA-IL-DLLEX)-高效液相色谱荧光法(HPLC-FD),分析蔬菜中速灭威、克百威、甲萘威、异丙威4种氨基甲酸酯类农药残留。考察系列影响萃取率的参数,包括萃取剂和分散剂的种类及其体积、样品p H、盐浓度、超声萃取时间。优化的萃取条件:200μL离子液体(IL,[C_6MIm][PF_6])为萃取剂,100μL四氢呋喃(THF)为分散剂,样品pH为7.0,不加盐,超声萃取5 min。在此条件下,方法的线性范围为0.02~1.0μg/m L,相关系数大于0.999,检出限(S/N=3)为0.006 3~0.018 mg/kg,3种阴性蔬菜中3个水平0.167,0.033和0.066 mg/kg的加标回收率为83.2%~110%,6次测定的相对标准偏差(RSD)为2.2%~5.1%。该方法应用于肇庆地区20种蔬菜中氨基甲酸酯类农药残留检测,所有蔬菜样品中均未检出速灭威、甲萘威和异丙威,6种蔬菜样品检出克百威浓度为0.017~0.22 mg/kg。     

分散液相微萃取荧光法速测小麦粉中过氧化苯甲酰

基于表面活性剂能提高荧光强度,分散液相微萃取能提高萃取率,建立测定小麦粉中过氧化苯甲酰的荧光分光光度法。讨论了溶剂种类,优化了测定温度、缓冲溶液、表面活性剂种类和用量对过氧化苯甲酰荧光强度的影响;讨论了萃取剂、分散剂的种类及用量。结果表明:无水乙醇溶液,冰浴,不加缓冲液,加100μL吐温-80(2 g/L),用70μL二氯甲烷做萃取剂和140μL乙腈做分散剂,超声1min对小麦粉样品进行预处理。在1cm微量比色皿中,激发波长(λex)为285nm,于发射波长(λe_m)310nm处读出荧光强度。在0.17~6.00μg/m L范围内,过氧化苯甲酰浓度与其荧光强度线性关系良好,相关系数为0.9993,检出限为0.2028 mg/kg。加标水平在1.29~2.55 mg/kg范围内,回收率为96.9%~105.6%,RSD为5.80%~6.80%(n=3)。新建方法可用于小麦粉中过氧化苯甲酰含量测定。     

悬浮固化-分散液-液微萃取-气相色谱法测定蔬菜中6种拟除虫菊酯类农药

建立了QuEChERS(Quick,Easy,Cheap,Effective,Rugged and Safe的缩写)结合悬浮固化-分散液-液微萃取(DLLME-SFO)-气相色谱测定蔬菜中6种菊酯类农药残留的方法。待测样品用含1%乙酸的乙腈溶液提取,提取液经混合固相分散萃取净化后经DLLME-SFO浓缩,最后用气相色谱(ECD)进行检测。实验考察了QuEChERS方法中提取溶剂的影响,DLLME-SFO中萃取剂种类与体积,分散剂种类和体积,盐浓度等对萃取效率的影响,优化结果为以40μL十六烷为萃取剂,1000μL乙腈为分散剂,5mL水中NaCl的加入量为1.25g。结果表明,在黄瓜和番茄基质中6种菊酯类农药在5、10、50μg/kg 3个添加水平下农药的平均回收率为84.84%~111.59%,相对标准偏差(RSD)为0.48%~9.61%,方法的检出限(LOD,S/N≥3)和定量限(LOQ,S/N≥10)分别为0.07~0.58μg/kg和0.22~1.94μg/kg。该方法快速、简便、灵敏、重复性好,可用于蔬菜中拟除虫菊酯类农药的快速筛查测定。     

GC-MS/MS法测定铁皮石斛中19种农药残留

建立固相萃取-气相色谱-三重四极杆串联质谱法测定铁皮石斛中19种农药残留的分析方法。石斛样品经乙腈提取,经ENVI-Carb/Florisil固相萃取小柱进行净化后,采用气相色谱-三重四极杆串联质谱法在多反应监测(MRM)模式下测定,外标法定量。19种农药成分在10μg/L~200μg/L范围内有良好的线性关系,相关系数在0.993 1~0.999 8范围内;19种农药成分在3个添加水平下(10、100、200μg/L),加标回收率范围为82.83%~109.29%,RSD%(n=5)为1.43%~5.74%;各农药成分的检出限均小于0.58μg/L。该方法可应用于石斛中多种农药残留的同时检测。     

SPE-GC-MS/MS法测定茶叶中49种农药残留

建立固相萃取-气相色谱-三重四极杆串联质谱法测定茶叶中49种农药残留的分析方法。样品经乙腈均质提取,经ENVI-Carb+Florisil固相萃取小柱进行净化后,采用气相色谱-三重四极杆串联质谱法在多反应监测(MRM)模式下测定,外标法定量。49种农药成分在10μg/L~100μg/L范围内有良好的线性关系,相关系数在0.995 2~0.999 9范围内;49种农药成分在3个添加水平下(10、50、100μg/L),加标回收率范围为71.43%~115.21%,RSD(n=6)为1.13%~11.05%;各农药成分的检出限均小于1.06μg/kg。该方法样品处理简单快速,灵敏度和选择性高,适用于日常检测工作。     

超声辅助离子液体分散液相微萃取石墨炉原子吸收光谱法测定食品中铅镉

建立了一种简单高效的超声辅助离子液体分散液液微萃取(UA-IL-DLLME)结合石墨炉原子吸收光谱法(GFAAS)测定食品中超痕量铅镉。以二乙基二硫代磷酸铵(DDTP)为配位剂,离子液体1-丁基-3-甲基咪唑六氟磷酸盐[C_4Mim][PF_6]为萃取剂,超声用于辅助分散离子液体和加速传质。考察优化了影响萃取效率的主要参数如离子液体的种类和体积、样品液p H、螯合剂的用量、超声时间、离心转速与时间等。在最优的萃取条件下,镉铅的校准曲线分别在0.05~20μg/L和0.5~40μg/L范围呈良好的线性,相关系数分别为0.9983 and 0.9969,检出限(S/N=3)分别为0.032和0.32μg/kg,相对标准偏差(RSD,n=11)分别为1.3%和1.8%。大米和白兰地中镉铅3个水平1.60、16.00、32.00μg/kg的平均加标回收率在95.2~102%范围。方法已成功用于检测不同食品中镉铅含量。     

分散液液微萃取-高效液相色谱法测定枸杞中α-生育酚

建立基于分散液液微萃取样品前处理法,并结合高效液相色谱紫外检测技术测定枸杞中α-生育酚的含量,考察影响分散液液微萃取的因素包括萃取剂和分散剂类型及用量、p H值、离子强度、萃取时间和萃取温度。方法的线性范围为100~50 000μg/L,r=0.999 7。在最优条件下,日内和日间重复性分别为2.9%和6.5%,检出限为3.1μg/L,定量限为10.2μg/L。并将该法成功应用于3种市售枸杞中α-生育酚含量的测定,加标回收率为85.7%~106.3%,相对标准偏差为0.68%~4.62%。方法具有有机溶剂用量少、操作简单快捷、准确度和灵敏度高、重复性好等优点。     

液相色谱-原子荧光法测定鱼肉中有机汞形态

建立微波辅助萃取-液相色谱-原子荧光(MAE-LC-AFS)测定鱼肉中甲基汞和乙基汞的分析方法。优化了液相色谱流动相、微博辅助萃取技术的提取剂浓度和萃取温度。在0~50μg/L范围内甲基汞和乙基汞的线性关系良好,线性相关系数大于0.999,甲基汞和乙基汞检出限(S/N=3)分别为0.07、0.13μg/L。3种样品在0.25、0.5、1.0 mg/kg 3个加标水平下的平均回收率为甲基汞80.3%~91.4%,乙基汞72.2%~83.3%,相对标准偏差(RSD)分别为2.4%~5.8%、2.3%~5.5%。该法适用于鱼肉中甲基汞和乙基汞的测定。     

SPE-HPLC-MS/MS测定粮食中玉米赤霉烯酮和脱氧雪腐镰刀菌烯醇

建立了以乙腈-水(84∶16,v/v)为提取溶剂、正己烷萃取和HLB固相萃取(SPE)净化、水和乙腈C18反相色谱梯度洗脱、电喷雾负离子多反应监测模式(MRM)同时测定粮食中玉米赤霉烯酮(ZEN)和脱氧雪腐镰刀菌烯醇(DON)2种物质含量的HPLC-MS/MS检测方法。结果表明,ZEN和DON检出限(以信噪比S/N=3计)依次为0.1μg/kg和2μg/kg,定量限(以信噪比S/N=10计)依次为0.3μg/kg和6μg/kg;两者线性范围分别为0.20~25μg/L(相关系数r=1.000 0)和4.0~500μg/L(相关系数r=0.999 9);不同样品2种目标物3个水平的加标回收率在88.7%~102.3%之间,相对标准偏差(RSD)在2.4%~7.3%之间。应用该方法对所检小麦样品进行分析,结果均发现严重污染样品的2种目标毒素。     

超高效液相色谱—串联质谱测定红烧老抽中六种合成色素的方法

建立了超高效液相色谱-串联质谱法(UPLC/MS/MS)同时测定红烧老抽中日落黄、柠檬黄、苋菜红、胭脂红、诱惑红、亮蓝等6种合成色素的方法。样品用水稀释后经过聚酰胺粉柱子净化,采用超高效液相色谱-串联质谱进行分析。采用0.02mol/L乙酸铵和甲醇作为流动相,梯度洗脱,流速为0.2mL/min,在7min内实现6种合成色素的良好分离。串联质谱条件是正离子模式电离,采用多反应监测模式(MRM)。6种色素在10~1000μg/L的范围内线性良好。6种色素的方法最低检出限是10μg/kg,加标回收率在80.0%～93.4%之间,相对标准偏差在2.4%～6.8%之间(n=6)。本方法分析快速、定性准确、检出限低,应用到基质复杂的老抽类液体复合调味料的检测中效果较佳。     

固相萃取-高效液相色谱检测葡萄酒中罗丹明B

建立固相萃取富集净化,高效液相色谱紫外检测葡萄酒中禁用色素罗丹明B的方法。葡萄酒样品中的罗丹明B经C18固相萃取,40%乙醇溶液清洗净化,80%的甲醇溶液洗脱后,用高效液相色谱紫外检测器进行测定。结果表明：罗丹明B在1.0～10.0μg/mL范围呈现良好的线性关系,相关系数0.9924;在1.5～3.5μg/mL添加水平时,平均回收率为72.06%,相对标准偏差为2.87%(n=5);定量测出限为0.25μg/mL。表明该方法灵敏度高,重复性良好,操作简便快速,适用于葡萄酒中罗丹明B的检测。     

Determination of Allura red in food samples after cloud point extraction using mixed micelles

A cloud point extraction process using mixed micelles of CTAB, Triton X-114 and Triton X-100 for preconcentration and spectrophotometric determination of trace amounts of Allura red in food samples was developed. The effect of different parameters such as concentration of surfactants, electrolyte concentration, temperature and pH on the cloud point extraction of Allura red was studied in detail and a set of optimum conditions were established. A linear calibration curve in the range of 20–1400 μg/L of Allura red was obtained. Detection limit based on 3S_b was 7.8 μg/L and the relative standard deviation for 75 μg/L of Allura red was 3.87 (n = 10). The method was applied to the determination of Allura red in food samples such as candy, soft drink and jellies.     

HPLC法检测蜜饯中20种合成着色剂含量

建立蜜饯中柠檬黄、新红、苋菜红、靛蓝、丽春红S、胭脂红、喹啉黄、日落黄、诱惑红、亮蓝、酸性红44、酸性红、食品红1、橙黄1、酸性红50、专利蓝V、赤藓红、酸性橙2、酸性橙8、亮蓝G共20种合成着色剂的高效液相色谱测定方法。试样用甲醇/氨水溶液提取,混合型弱阴离子反相固相萃取柱净化,甲醇/20 mmol/L乙酸铵为流动相梯度洗脱,二极管阵列检测器多波长检测,外标法定量。结果表明,该方法在0.1~20 μg/mL的线性范围内相关系数均大于0.999,加标回收率范围为84.0%~104.5%,相对标准偏差（RSD）为1.3%~5.3%。该方法操作便捷、稳定性好、回收率高,适用于蜜饯中20种合成着色剂的同时分析检测。该方法可以扩展应用于其他同结构性质的色素分析,对其他食品类别中色素的检测也具有参考意义。     

QuEChERS-高效液相色谱法检测不同畜禽产品中5种氟喹诺酮类的药物残留

目的建立QuEChERS法检测多种畜禽产品中5种氟喹诺酮类药物残留。方法采用酸化的乙腈溶液提取猪、牛、羊、鸡和鸭等畜禽的肌肉、皮脂、脂肪、肝和肾组织中氟喹诺酮类残留,用微型高速分散机在离心管内同时完成均质与提取,采用增强型脂质去除过滤柱对提取物进行2次洗脱,用高效液相色谱-可变波长荧光检测器法检测。结果达氟沙星和恩诺沙星的线性范围为5~500μg/L,沙拉沙星的线性范围为2.5~100.0μg/L,二氟沙星的线性范围为10~2000μg/L,氟甲喹的线性范围为10~3000μg/L;检出限为2~10μg/kg,定量限为5~25μg/kg。畜禽产品基质中各药物的空白样品加标回收率均为76.09%~93.20%,RSDs为2.98%~6.29%。结论该方法快速、准确、灵敏,适合测定猪、牛、羊、鸡和鸭的肌肉、脂肪(皮脂)、肾和肝中沙拉沙星、恩诺沙星、达氟沙星、二氟沙星和氟甲喹药物残留。     

Occurrence of Ochratoxin A in Chinese wines: influence of local meteorological parameters

A total of 119 wines, including 115 dry wines (77 red, 34 white, 4 rosé) and 4 ice wines, were obtained from four major regions around China (east, northeast, west, and northwest) from 1999 to 2009. Ochratoxin A (OTA) was detected by solid-phase extraction and high-performance liquid chromatography with fluorescence detection. The OTA levels ranged from <0.1 to 5.65 μg/L. The wines from the northeast area had the highest OTA level, with an average concentration of 2.18 μg/L. Analysis of the correlation between meteorological parameters and the OTA concentration in red wine revealed that the OTA concentration was positively correlated with rainfall in August, but negatively correlated with the average temperature. No significant correlation was found with the daily range of temperature and relative humidity. The results show that climate factors affect the OTA distribution in wines from the four major regions of China.     

Evaluation of Dispersive Liquid–Liquid Microextraction–HPLC–UV for Determination of Deoxynivalenol (DON) in Wheat Flour

A fast and simple method for the extraction of deoxynivalenol (DON) from wheat flour using dispersive liquid–liquid microextraction (DLLME) followed by high-performance liquid chromatography–UV detection has been developed and compared with immunoaffinity column cleanup (IAC) process. The influence of several important parameters on the extraction efficacy was studied. Under optimized conditions, a linear calibration curve was obtained in the range of 50–1,000 μg/L. Average recoveries of DON from spiked wheat samples at levels of 500 μg/kg for DLLME and IAC ranged from 72.9?±?1.6 and 85.5?±?3.1, respectively. A good correlation was found for spiked samples between DLLME and IAC methods. The limit of detection was 125 and 50 μg/kg for DLLME and IAC method, respectively. Advantages of DLLME method with respect to the IAC have been pointed out.     

中空纤维膜三相液相微萃取法测定猪尿及牛奶中的盐酸克伦特罗

本文建立了中空纤维膜三相液相微萃取(hollow fiber based liquid-liquid-liquid microextraction,HF-LLLME)富集浓缩猪尿及牛奶中的痕量盐酸克仑特罗,后续采用高效液相色谱/紫外(high performance liquid chromatography with a ultraviolet detector,HPLC/UV)对其进行定量分析。对影响HF-LLLME萃取效率的因素如有机溶剂种类、选择有机萃取时间、搅拌速率以及盐效应等进行了优化,最终溶剂为甲苯,萃取时间为30 min,搅拌速率为4000 r/min,给予相中不加盐,在最优条件下,考察了该方法分析性能,结果表明:该方法在1.5~1000 μg/L内具有良好的线性(r=0.9980),方法检出限(S/N=3)、定量限(S/N=10)分别为0.5和1.5 μg/L,HF-LLLME带来的高倍浓缩效率将HPLC/UV测定克仑特罗的灵敏度提高约2个数量级。萃取过程相对标准偏差(n=7)RSD=8.8%,对猪尿和牛奶分别进行5、50、500 μg/L三个水平的加标回收实验,回收率为:猪尿87.0%~102.4%(相对标准偏差为5.1%~9.8%),牛奶80.2%~94.4%(相对标准偏差为2.7%~6.4%)。该方法富集效率高、操作简单、环保、经济、可靠,适用于定量分析尿样及牛奶等中痕量的盐酸克伦特罗。     

液相色谱-串联质谱法测定食品中红2G、酸性红、酸性红52着色剂方法研究

建立了食品中红2G、酸性红、酸性红52的高效液相色谱-串联三重四级杆质谱测定方法。样品经聚酰胺粉吸附法净化,以乙腈和乙酸铵为流动相,梯度洗脱分离,在负离子和多反应监测(MRM)模式下进行定性定量分析。食品中红2G、酸性红、酸性红52的方法检出限分别为5μg/L、6μg/L、1μg/L;在30μg/L-1000μg/L浓度范围内线性良好,相关系数较好;方法平均回收率在80%以上,相对标准偏差均小于10%。该方法定性准确、灵敏度高,适用于食品中红2G、酸性红、酸性红52这3种合成着色剂的同时检测。     

A Novel Cationic Surfactant-Assisted Switchable Solvent-Based Dispersive Liquid–Liquid Microextraction for Determination for Orange II in Food Samples

In this research, a new and green procedure based on the cationic surfactant-assisted switchable solvent-based dispersive liquid–liquid microextraction (CS-SS-DLLME) with UV-vis spectrophotometry was used for the extraction and determination of the Orange II dye in food samples. The main feature of the switchable solvent is the simple and reversible conversion of polarity protonated triethylammonium carbonate (P-TEA-C, ionic) to triethylamine (TEA, nonionic) by adding NaOH. This extraction method is based on hydrophilicity switchable solvent and ion pair effect of cationic surfactant. Simplicity, high-performance extraction, rapidity of the process, increase of stability, and reduction of the extractive phase volatility are other advantages of the proposed method. The parameters including the extraction and preconcentration of Orange II were studied and optimized. Under optimal conditions, the calibration curve was linear within the range of 2–450 μg/L and the detection limit was 0.9 μg/L and the relative standard deviation (RSD) for 80 μg/L of Orange II was 1.68%. This developed method was used successfully for the determination of Orange II in food samples.