罗丹明B分子印迹固相萃取小柱的研制及应用

研制一种对罗丹明B具有特异性识别性能的分子印迹固相萃取小柱。用沉淀聚合法制备罗丹明B分子印迹聚合物,通过静态平衡吸附实验及固相萃取实验表征其性能,并对市售辣椒样品中的罗丹明B进行测量。罗丹明B模板聚合物的吸附能力明显优于空白聚合物;印迹固相萃取小柱对罗丹明B标准溶液(0.05 mmol/L)一次性萃取率为98.24%,实际样品测量的回收率为90.0%~95.0%,测定结果的相对标准偏差为0.9%~1.7%(n=3)。罗丹明B分子印迹固相萃取小柱选择性好、萃取率高,可应用于食品、化妆品检测等相关领域。     

白菜中有机磷农药的电纺纳米纤维固相萃取-高效液相色谱法测定

以聚苯乙烯电纺纳米纤维为固相萃取介质填装固相萃取小柱,对白菜中的5种有机磷农药(杀扑磷、马拉硫磷、辛硫磷、丙溴磷、毒死蜱)富集净化,甲醇洗脱吸附在小柱上的农药后,用高效液相色谱-紫外检测器进行检测.对萃取次数、白菜样品提取液、洗脱液、pH值进行了优化,杀扑磷、马拉硫磷、辛硫磷、丙溴磷、毒死蜱在固相萃取小柱上的最大吸附量分别为2.9、3.5、5.6、3.7、7.8 mg/g,5种有机磷农药的平均加标回收率为68% ～97%,相对标准偏差为1.6% ～4.7%.测定喷洒5种农药后的白菜样品的萃取回收率为65% ～93%,相对标准偏差为1.6% ～4.0%,5种农药的检出限为0.02 ～0.1 mg/kg.该方法操作简单、价廉,能够用于白菜中有机磷农药的测定.     

尼泊金乙酯分子印迹固相萃取小柱的研制及应用

研制了一种对尼泊金乙酯具有特异性识别性能的分子印迹固相萃取小柱。用本体聚合法制备尼泊金乙酯分子印迹聚合物,通过静态平衡吸附实验及固相萃取实验表征其固相萃取性能,并结合UV法对滴眼液中的尼泊金乙酯进行测定。结果显示,尼泊金乙酯模板聚合物的吸附能力强于空白聚合物;印迹固相萃取柱对尼泊金乙酯标准溶液(0.04mmol/L)一...     

二氧化锆包覆的二氧化硅核壳型填料的制备及在选择性吸附磷脂中的应用研究

提出了一种基于ZrO2/SiO2核壳型材料吸附磷脂的分析方法。首先利用NH3/H2O内部水解法制备了含不同比例ZrO2包覆的ZrO2/SiO2核壳型颗粒,并通过电镜和紫外吸收漫反射图谱对其进行了表征,证明在SiO2表面包覆有ZrO2材料。采用RP-HPLC-ELSD(Reversed phase-high performance liquid chromatogra-phy-evaporative light scattering detector),以甲醇-水(含醋酸铵)为流动相,优化并建立了5种磷脂的分析方法。在以上基础上将ZrO2/SiO2核壳型材料制成固相萃取(Solid phase extraction,SPE)小柱,以5种磷脂标准品为研究对象,用RPLC-ELSD方法评价了SPE小柱吸附磷脂的效率。发现包覆有3.5%和7%ZrO2的ZrO2/SiO2核壳型材料吸附磷脂的能力均强于单纯的ZrO2材料,且3.5%的ZrO2/SiO2核壳型材料吸附效果最好,并将其初步应用于血清中磷脂的选择性吸附,结果表明,通过SPE富集后,能检测到更多的磷脂类代谢产物。     

火焰原子吸收光谱法测定复方丹参片中微量元素各形态含量

采用火焰原子吸收光谱法对复方丹参片水煎液及人工胃酸提取液中具有生物活性的微量元素铁、铜、锰和锌的形态分布进行了研究。用OasisTMHLB固相提取小柱分离药物的两种提取液中所述4种元素的无机态和有机态;用D401螯合树脂分离4种元素的稳定态和不稳定态;用Amberlite XAD-7大孔吸附树脂分离得到与丹酚酸的有机结合态。结果表明:锌、铜的蛋白质结合态分布较高,多糖结合态中以铜元素为主,丹酚酸有机结合态中铁元素的含量最高。     

高效液相色谱测定经PT-系列氧化铝小柱预处理后狗血清中儿茶酚胺

氧化铝吸附法提取生物样本中的儿茶酚胺已被广泛地应用,但在操作上需反复洗涤、离心,比较麻烦,本文探讨了用国产PT-系列酸性氧化铝小柱进行预处理的条件,用内标法测定了肺动脉高压情况下的狗血清中去甲肾上腺素(NE)和肾上腺素(E)含量的变化,得到较为满意的结果。     

活性炭吸附–固相萃取–离子色谱法快速测定垃圾渗滤液中的阴离子

建立了活性炭吸附–固相萃取–离子色谱法快速测定垃圾渗滤液中F–,Cl-,NO3–,PO43–,SO42–5种阴离子的方法。100 m L样品先经10 g预先洗涤烘干的活性炭吸附,然后通过吸附特性不同的ENVI–18(C18小柱)、PSA固相萃取小柱。利用C18小柱对水中有机污染物的萃取及键合相有双齿配体的PSA小柱对金属离子的螯合,除去渗滤液中大量的有机物和重金属,再经离子色谱检测。5种离子的质量浓度在1~10 mg/L范围内与其色谱峰面积呈良好的线性关系,线性相关系数大于0.999,F–,Cl-,NO3–,PO43–,SO42–的检出限分别为0.02,0.02,0.08,0.15,0.09 mg/L。5种离子的平均加标回收率为96%~105%,测定结果的相对标准偏差小于6%(n=6)。该方法简便快捷,测定结果准确可靠,可用于垃圾渗滤液中F–,Cl-,NO3–,PO43–,SO42–5种阴离子的测定。     

吡咯烷二硫代甲酸铵纤维素的表征及其填充小柱法采集大气中的铅

将优良的重金属螯合剂－吡咯烷二硫代甲酸铵（ＡＰＤＣ）通过间接醚化法接枝到自然界分布广泛的棉纤维上，制成了性能优越、成本低廉的ＡＰＤＣ螯合纤维素（ＣＣ－ＡＰＤＣ），并对其结构及吸附性能进行了表征。首次用ＣＣ－ＡＰＤＣ填充小柱法采集测定大气中的铅。方法简便、快速，准确度、精密度均很好，是对大气中测铅的常规环境监测方法的改进。     

丹参酚酸B生产中去除胶体类杂质的工艺方法

胶体类杂质的去除是丹参酚酸B(salvianolic acid B, SB)纯化工艺的难点之一。实验中基于前沿色谱与置换色谱相结合的原则,改良常规大孔吸附树脂柱的操作方法,将树脂按一定的比例装入大小两支柱。小柱与大柱串联,上样至胶体类杂质在小柱上达到吸附饱和,用50%甲醇单独洗脱大柱上的SB部分,利用树脂吸附色谱法实现了SB与胶体类杂质的分离。结果表明,经过去胶体类杂质处理后,SB的加权平均纯度由59.6%提高到64.5%,收率由69.75%提高到80.0%,并且SB的洗脱条件降低。本工艺方法适合于规模化工业生产。     

葡萄酒中白藜芦醇的固相萃取GC／MS法测定及其生理活性？…

用反向Ｃ１８固相萃取小柱对葡萄酒进行了预处理，然后用ＢＳＴＦＡ硅烷化试剂对萃取物进行了衍生化处理，用气相色谱／质谱对葡萄酒中顺式、反式白藜芦醇进行了同时测定，建立了定量分析方法。     

粮油作物及茶叶中农药多残留检测的前处理技术进展

综述了粮油作物和茶叶中农药多残留检测的前处理技术,包括超临界流体萃取、加速溶剂萃取、搅拌棒吸附萃取、分散固相萃取、固相微萃取和在线凝胶渗透色谱等样品前处理方式,并详细介绍了各种方法的原理、优点及适用范围,可为粮油作物和茶叶中农药多残留检测技术的发展提供参考。     

Supercritical fluid extraction and quantitative determination of organophosphorus pesticide residues in wheat and maize using gas chromatography with flame photometric and mass spectrometric detection

An automated method using supercritical CO2 and clean-up by solid-phase extraction (SPE) using graphitized carbon black, has been developed for the quantitative determination of organophosphorus pesticide (OPP) residues in wheat and maize. Recoveries were as good as, or better than, those obtained using liquid extraction (LE) and gel permeation chromatography (GPC) for 10 OPP's spiked at levels equivalent to 0.05 and 0.50 microg/g. Lower limits of detection were possible using supercritical fluid extraction (SFE). Incurred residues were found in wheat and maize samples, and good agreement was obtained using SFE+SPE and LE+GPC. The SFE+SPE method required less analyst time and organic solvent, and hazardous waste was reduced.     

分散固相萃取净化茶叶中20种农药残留量的GC-μECD测定

建立了改进的分散固相萃取(DSPE)提取净化、GC-ECD检测茶叶中六六六、敌敌涕、硫丹、拟除虫菊酯、乙草胺、氟虫腈、溴虫腈等茶叶国际贸易中较为关注的20种农药残留量的方法.前处理过程:(1)以2 mL乙腈提取0.5g茶叶样品,涡旋振荡2 min,离心5 min(5000 r/min);(2)取1mL上清液与PSA(2...     

Simultaneous determination of 103 pesticide residues in tea samples by LC‐MS/MS

A simple and sensitive method was developed and validated for the simultaneous determination of 103 pesticide residues in tea by LC‐MS/MS. For the analysis of the pesticide with polarity, thermal lability or low volatility, this LC‐MS/MS method has an advantage over GC. In this work, residual pesticides were extracted from the tea sample with ACN and then purified using Carb‐NH₂ SPE cartridges. Using the multiple reaction monitoring mode, the pesticides were quantified and identified by the most abundant and characteristic fragment ions. The recoveries obtained for each pesticide ranged between 65 and 114% at three spiked concentration levels. The intra‐day precisions were lower than 19.6%. Good linear relationships were observed with the correlation coefficients r² >0.996 for all analytes. The established method was successfully applied to the determination of pesticide residues in real tea samples.     

快速滤过型净化结合气相色谱-串联质谱法同时检测茶叶中10种拟除虫菊酯农药残留

建立了快速滤过型净化(m-PFC)结合气相色谱-串联质谱(GC-MS/MS)测定茶叶中10种拟除虫菊酯类农药残留的方法。比较了采用不同提取溶剂(乙腈、丙酮和乙酸乙酯)和不同提取方式(不加水浸泡和加水浸泡)时10种农药的提取效率;比较了2种QuEChERS净化管和m-PFC柱对茶叶提取液的净化效果和农药残留的回收率。结果表明,茶叶样品不加水浸泡,用乙腈提取效果最好;m-PFC柱对茶叶提取液净化效果良好,而且能保证较高的农药回收率。10种拟除虫菊酯农药在相应的范围内有良好的线性关系,相关系数(R²)大于0.998 0; 10种农药在4个水平添加下的回收率为87.5%～111.3%, RSD为2.1%～8.9%。方法的检出限为0.001～0.015 mg/kg,定量限为0.003～0.05 mg/kg。利用该方法检测市售50例茶叶样品中10种拟除虫菊酯农药的残留,检出率为48%,但农药残留量均在国家标准限量值以下。与传统QuEChERS法和固相萃取法相比,该方法具有操作简单、准确度和精密度良好等优点,为多种拟除虫菊酯类农药在茶叶中的残留测定提供了快速检测的新方法。     

茶叶浸出液中农药残留表面拉曼光谱检测与初步定量分析

选取甲基对硫磷和水胺硫磷为研究对象,改良了传统的QuEChERS前处理工艺,以自制纳米金溶胶为增强基底,利用表面增强拉曼光谱(SERS)技术,对茶叶浸出液中的农药残留进行检测。通过比对两种有机磷农药的拉曼特征峰进行定性分析。同时,选取570,1034,1107和1202 cm^-1等拉曼位移附近的特征峰光谱数据,利用微分等数学手段,结合偏最小二乘法(PLSR)建立回归方程,预测样品中农药残留含量。所得预测数值与气相色谱-质谱联用(GC-MS)法检测值对比,验证本方法的可行性与可信度。结果表明:基于SERS技术对上述两种有机磷农药的检出限可达0.05 mg/L;通过数学模型分析建立回归方程,其线性相关系数范围为0.9077~0.9824,预测均方根误差(RMSEP)范围为0.77%~2.68%;利用回归方程得到的预测值与GC-MS检测结果基本接近,相对误差范围-5.16%~9.03%,回收率为81.4%~115.1%,说明可以用SERS技术对茶叶浸出液中的有机磷农药残留进行定性和初步定量分析。     

在线凝胶渗透色谱-气相色谱/质谱法检测茶叶中的153种农药残留

建立了在线凝胶渗透色谱-气相色谱/质谱(GPC-GC/MS)分析茶叶中153种农药残留的方法。样品用乙腈超声提取,提取液经石墨化炭黑固相萃取柱净化后,经GPC-GC/MS在线净化、分离和检测。方法的加标回收率为73.32%～117.05%,相对标准偏差为0.76%～13.18%。方法的检出限和定量限范围分别为0.0003～0.006 mg/kg和0.001～0.02 mg/kg。该方法样品前处理简单、分析时间短,灵敏度和精密度均符合农药多残留检测技术的要求,适用于茶叶中多种农药残留的检测。     

Pressurised fluid extraction (PFE) as an alternative general method for the determination of pesticide residues in rape seed

A pressurised fluid extraction (PFE) multi-method has been developed for the determination of pesticide residues in rape seed. The method was validated for 25 different pesticides and metabolites. The reliability and efficiency of PFE for extracting pesticide residues from rape seed was investigated. The traditional extraction solvent, hexane saturated with acetonitrile, was used at elevated temperature and pressure. With increased temperature, the extraction kinetics were improved but at the same time more co-extractives were obtained in the form of lipids. When 1 g of rape seed was extracted at temperatures from 60 degrees C to 150 degrees C, the lipid content extracted was found to be as high as 17-26%. An additional clean-up step was therefore required and lipid co-extractives were effectively removed by gel permeation chromatography. The interpretation of the chromatograms and the quantification of the results were satisfactorily improved by the removal of interfering lipids. The developed method was used to extract vinclozolin and iprodione from incurred samples, resulting in a concentration in accordance with the results using conventional liquid-liquid extraction (LLE) between hexane and acetonitrile and also supercritical fluid extraction (SFE) using carbon dioxide. The results of the present study suggest that PEE is a good alternative extraction technique for the determination of pesticide residues in oil seed. Despite the necessity for a lipid-removal clean-up step, the PFE technique facilitated the extraction process by faster extractions and the possibility of automated analysis.     

应用搅拌棒吸附萃取-热脱附-气相色谱-质谱测定烟叶和茶叶中拟除虫菊酯类农药残留

应用搅拌棒吸附萃取(SBSE)技术分别萃取烟叶和茶叶中的5种拟除虫菊酯,并利用热脱附系统将萃取到的物质进行热脱附,然后通过气相色谱-质谱联用仪(GC-MS)进行分析测定。实验过程中对影响SBSE的因素及影响热脱附的条件进行了优化。在优化条件下,采用外标法分别对烟叶和茶叶中的5种拟除虫菊酯类农药残留进行了定量分析。结果表明,烟叶中5种拟除虫菊酯的检出限范围为3.3~11.4 ng,加标回收率为94.8%~103.4%,6次测定的相对标准偏差（RSD）为5.3%~8.6%;茶叶中5种拟除虫菊酯的检出限范围为4.2~10.5 ng,加标回收率为98.2%~110.1%,6次测定的RSD为5.0%~9.6%。实验证明该法具有较高的准确度、灵敏度和较好的重现性,可用于烟叶和茶叶中拟除虫菊酯类农药残留的快速分析测定。     

Determination of 2,4-D and Dicamba in food crops by MEKC

Summary The determination of 2,4-D (2,4-dichlorophenoxyacetic acid) and Dicamba (2-methoxy-3,6-dichlorobenzoic acid) residues in sugar cane, rice and corn was performed by a supercritical fluid extraction (SFE) method using CO₂/acetone as extraction mix and an SFE apparatus developed in our laboratory. The extracts were cleaned up after extraction by both liquid-liquid partition and a Florisil column. Micellar electrokinetic capillary chromatography (MEKC) coupled with ultraviolet on-column detection was used for the analysis of these pesticides. The detection limits were improved by the preparation of a special detection cell with an increased pathlength that gave detection limits of ca. 0.6 pg for 2,4-D and Dicamba. Our results demonstrated that capillary electrophoresis can be a powerful new analytical tool for pesticide residue analysis.