凝胶渗透色谱-固相萃取净化测定茶叶中16种菊酯残留量

建立了以凝胶渗透色谱(GPC)和固相萃取(SPE)净化,气相色谱-质谱(GC-MS)负化学源(NCI)技术测定茶叶中七氟菊酯、 四氟菊酯、丙烯菊酯、联苯菊酯、胺菊酯、甲氰菊酯、氯氟氰菊酯、氟丙菊酯、苯醚氰菊酯、氟氯氰菊酯、氯氰菊酯、氟氰戊菊酯、氰戊菊酯、 氟胺氰菊酯、溴氰菊酯、氯菊酯等16种菊酯残留量的方法.样品经V(丙酮)∶V(乙酸乙酯)∶V(正己烷)＝1∶2∶1提取,经GPC去除大分子的色素和类脂杂质,弗罗里硅土 SPE柱进一步净化,以毒死蜱同位素D-10作内标,内标法定量.方法的回收率67.2%～108%之间.变异系数小于18%.16种菊酯方法定量限在0.0125～0.025 mg/kg之间.     

牛肉中7种拟除虫菊酯类农药残留的固相萃取-超高效液相色谱-串联质谱法测定

建立了牛肉组织中胺菊酯、氯氰菊酯、溴氰菊酯、氟胺氰菊酯、氰戊菊酯、氟氯苯氰菊酯、氯菊酯7种拟除虫菊酯类农药残留的超高效液相色谱-串联质谱测定方法,样品经乙腈提取后,吹干提取液,用正己烷溶解,氟罗里硅土固相萃取柱净化,经BEHC18色谱柱分离,以0.1%甲酸的甲醇溶液和0.1%乙酸铵溶液为流动相进行洗脱。电喷雾正离子模式(ESI+)电离,多反应监测模式(MRM)检测,外标法定量。结果表明,7种拟除虫菊酯类农药标准溶液在10～1000μg/L范围内呈良好线性,r2均大于0.998;方法检出限为5μg/kg,定量下限为10μg/kg;7种拟除虫菊酯农药在10～50μg/kg添加水平内的回收率为81%～116%,批内、批间RSD均小于15%。该方法具有简便快捷、灵敏度高、定性准确等优点,能满足食品安全检测有关法规的要求。     

SPE-RP-HPLC法测定羊肉组织中胺菊酯和三氟氯氰菊酯残留量

建立了羊肉组织中胺菊酯和三氟氯氰菊酯的固相萃取-反相高效液相色谱测定法。采用氟罗里硅土固相萃取柱(1000 mg/6 mL)进行固相萃取。以Shim-pack VP-ODS(200 mm×4.6 mm)柱为分析柱,流动相为甲醇:水=95:5(V/V),流速为0.7 mL/min。胺菊酯和三氟氯氰菊酯分别在0.01～6.40μg/mL(r=0.9999)和0.068～7.20ug/mL(r=0.9998)范围内与峰面积呈良好线性关系,检出限分别为0.001μg/mL和0.002μg/mL,胺菊酯和三氟氯氰菊酯的回收率为90.2%～101.4%,相对标准偏差为2.3%～4.0%。该方法可作为羊肉组织中胺菊酯和三氟氯氰菊酯含量监测的控制方法。     

蜂蜜中氟胺氰菊酯残留量的测定

蜂蜜样品经过碱解、溶剂提取、固相萃取净化处理后 ,用配有双柱双电子捕获检测器的气相色谱仪测定其中氟胺氰菊酯的残留量。利用气相色谱 -质谱联用仪验证了氟胺氰菊酯的两个旋光异构体的存在。通过 0 .0 1、0 .1和 0 .2mg/kg 3个水平的添加实验 ,在HP - 5 0 + 和HP - 1色谱柱上测定 ,回收率分别为 86 .3% 95 .37%、82 .83% 91.4 % ,检出限分别为 0 .0 0 7、0 .0 0 3mg/kg ,RSD <5 % (n =3)。     

气相色谱法测定苹果和土壤中的高效氯氟氰菊酯

建立了改进的QuEChERS-气相色谱检测苹果和土壤中高效氯氟氰菊酯残留的分析方法,考察和评价了苹果和土壤两种基质对高效氯氟氰菊酯的基质效应。苹果和土壤样品均用乙腈提取,经石墨化碳黑（GCB）净化后直接进样分析。结果表明：在优化后的QuEChERS条件下,高效氯氟氰菊酯在0.05~10 mg/L范围内线性关系良好,相关系数（R²）大于0.999,检出限为0.12~0.15 μg/kg,定量限为0.38~0.50 μg/kg。用基质标准曲线定量时,高效氯氟氰菊酯在土壤和苹果中的回收率分别为88.29%~97.65%和80.70%~98.69%。苹果和土壤样品对高效氯氟氰菊酯都表现出基质增强效应。该方法的回收率均能达到残留分析要求,用基质配制标准溶液能够有效、方便地校正气相色谱-电子捕获检测器测定高效氯氟氰菊酯残留时的基质效应,且能应用于苹果和土壤实际样品的检测。     

气相色谱法测定荔枝中7种拟除虫菊酯类农药残留量

采用气相色谱法测定荔枝中联苯菊酯、甲氰菊酯、氯氟氰菊酯、氟氯氰菊酯、氯氰菊酯、氰戊菊酯和溴氰菊酯等7种拟除虫菊酯类农药的残留量。荔枝样品用丙酮-正己烷(1+1)混合液提取,所得提取液用活性炭柱和中性氧化铝柱的串联柱净化,用DB-35毛细管色谱柱分离,电子捕获检测器检测。7种拟除虫菊酯类农药的质量浓度均在0.05~0.8mg·L~(-1)内与其峰面积呈线性关系,方法的检出限(3S/N)在0.005~0.01mg·kg~(-1)之间。在0.05,0.1,0.2mg·kg~(-1)等3个浓度水平进行加标回收试验和精密度试验,回收率在81.0%~104%之间,测定值的相对标准偏差(n=6)在1.7%~5.1%之间。采用此法测定了荔枝样品中联苯菊酯的含量,所得测定值与行业标准方法测定结果相符。     

2.5%高效氯氟氰菊酯乳油的高效液相色谱分析

采用高效液相色谱法,以V(乙腈):V(水)=80:20为流动相,固定相采用Zorba×SB-C18柱,紫外检测波长为230 nm,外标法定量,25℃条件下测定2.5%高效氯氟氰菊酯乳油.结果显示其有效成分高效氯氟氰菊酯能够与未知物有效分离,得到较好的检测结果:测得氯氟氰菊酯的回收率99.3%～99.8%,相对标准偏差(RSD,n=5)为0.19%,线性相关系数0.9999.     

流动相离子色谱法同时测定植物中残留的矮壮素和缩节胺

以离子对试剂作流动相,采用离子对抑制电导检测法同时测定植物中残留的矮壮素和缩节胺。简单处理后的样品经过Dionex　IonPac NG1保护柱和NS1分离柱,在流速为1.00 mL/min、淋洗液为1.00 mmol/L九氟戊酸(作为离子对试剂)-7%(体积分数,下同)乙腈时等度洗脱分离,能够快速稳定出峰,且被测物与其他干扰离子充分分离。矮壮素和缩节胺的检出限分别为0.1546和0.1714 mg/L,在1～100 mg/L范围内具有良好的线性关系和重现性。对实际样品进行测定,矮壮素和缩节胺的回收率范围分别为96.06%～104.6%和98.53%～103.7%,相对标准偏差小于3%。该方法分析结果令人满意,可以满足矮壮素和缩节胺常规的定性、定量分析需求。     

气相色谱法测定茶叶及土壤中的高效氯氟氰菊酯残留量

建立了气相色谱测定茶叶及土壤中高效氯氟氰菊酯残留量的分析方法。茶叶和土壤样品用正己烷提取,毛细管柱分离,气相色谱-电子捕获检测器(GC-ECD)检测。结果表明: 在高效氯氟氰菊酯添加量为0.02～2.00 mg/kg范围内,高效氯氟氰菊酯在鲜茶叶和土壤中的平均添加回收率分别为89.0%～94.1%和89.8%～94.7%,相对标准偏差(RSD, n=5)分别为3.0%～4.9%和2.5%～4.2%,方法的最低检出限(S/N=3)为0.002 mg/kg。采用该方法测定2.5%高效氯氟氰菊酯微乳剂在湖南长沙茶叶及土壤中的消解动态,其符合一级动力学消解模式,消解方程分别为y=3.1996e-0.3394x和y=0.1224e-0.1036x,相关系数分别为0.9956和0.9247。在茶叶中的半衰期为2.04 d,在土壤中的半衰期为6.69 d。该方法为湖南长沙地区茶叶种植科学合理地使用杀虫剂高效氯氟氰菊酯提供了依据。     

大鼠尿液与粪便中氟噻草胺的UPLC-MS/MS法测定

建立了一种测定大鼠尿液和粪便中氟噻草胺含量的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。粪便与尿液样品采用乙腈提取;液相色谱分离采用Phenomenex反向C18色谱柱(50 mm×4. 6 mm,5μm),以0. 1%甲酸水和乙腈为流动相,流速0. 6 m L/min;质谱检测采用电喷雾离子源,正离子模式和多反应监测(MRM)方式进行扫描。结果表明:氟噻草胺在尿液(0. 10～10. 0 mg/L)和粪便(0. 25～50. 0 mg/L)中线性关系良好,相关系数r 0. 99,尿液和粪便中氟噻草胺的定量下限分别为0. 10 mg/L和0. 25 mg/L;质控样品的日内与日间相对标准偏差不大于9. 9%。样品稳定性为93. 7%～108%,尿中平均提取回收率为97. 0%～98. 8%,基质效应为98. 8%～107%,均符合生物分析方法验证的要求。考察了大鼠单次灌胃给予氟噻草胺400 mg/kg后的排泄动力学,144 h内尿液与粪便的总累积排泄率为12. 62%,其中尿中的累积排泄率为1. 12%,粪便中的累积排泄率为10. 13%,表明氟噻草胺主要经粪便排泄。该法灵敏、专属、准确,可用于大鼠尿液、粪便中氟噻草胺浓度的测定。     

快速色谱

基于柱液相色谱和薄层色谱之间的关系,讨论如何为快速色谱选择流动相,并介绍此技术手工操作的步骤.     

Extraction chromatography of common anions in liquid-liquid anion exchange systems. Part. III. Monobasic aliphatic organic acids and their sodium salts as eluants

Summary The chromatographic behaviour of anions on paper strips treated with tri-n-octylamine (TOA) salts or Aliquat 336 and developed with aqueous solutions of acetic, formic, monochloroacetic or trifluoroacetic acids and their sodium salts was investigated. Liquid-liquid extraction of organic acids by 0.1 M solution of TOA in benzene as well as the anion exchange between benzene solutions of TOA salts or Aliquat 336 (in acetate form) in benzene and aqueous solutions of sodium halides was also studied. It was found that extraction increases in the following order of the acids: CH₃COOOH<HCOOH<CH₂CICOOH<CF₃COOH; the relative affinity of organic anions to the quaternary alkyl-ammonium cation also increase in a similar order. The extraction of acid in excess over the amount necessary to neutralize the amine was observed for all four acids. The R_F values of anions investigated depend markedly on the type of organic acids or their salts and their concentration in the mobile phase. Halide ions are more strongly retained on paper treated with Aliquat 336 as compared with TOA salts. The chromatographic systems investigated offer many possibilities to separate various anion mixtures.Parts and II: refs. [1, 2].     

A review of advances in two-dimensional thin-layer chromatography

Although there are many simple thin-layer chromatography (TLC) separations, many more are complex and involve more than a few components, that means having to use special high-performance TLC (HPTLC) plates or microspotting or banding devices to increase its resolving power if developing in only one direction. However, adding a second development to perform two-dimensional TLC (2D TLC) allows even better resolution of complex samples. This is because different modes of chromatography are being invoked by the use of one stationary phase with two mobile phases, bilayer plates, graft TLC, or multidimensional TLC. This paper is a review of recent applications that have benefitted from using 2D TLC in its various forms. They were chosen for their variety of sample types as well as the unique choices of plates and/or mobile phases made by the researchers to yield improved separations.     

Unified chromatography: Fundamentals,instrumentation and applications†

The concept of unified chromatography has been in existence for 50 years after the work of Giddings proposing that all modes of chromatography (gas chromatography, liquid chromatography, supercritical fluid chromatography and so on) may be treated together under a single unified theory. His idea was partially fulfilled 23 years later by Ishii, Takeuchi and colleagues, who demonstrated for the first time the possibility to analyze a complex sample containing substances with a wide range of boiling points and polarities in the same instrument and column, just by varying the mobile phase pressure and temperature to change from one chromatographic mode to another. This approach has been demonstrated through application to the separation of complex mixtures in several areas including crude oil, edible oils and polymers. Still, unified chromatography has not yet been fully developed. In the present work, we will review the fundamentals, instrumentation and several applications of the technique. Also discussed are the drawbacks that still hinder development, as well as the recent developments and trends in instrumentation and columns that suggest the most feasible ways forward to the full development of unified chromatography.     

TLC as a pilot technique for the optimization of gradient HPLC II. Use of data obtained from RP-18 plates for the prediction of gradient programs in reversed-phase liquid chromatography

Summary A method is described and experimentally verified permitting the determination of the optimal gradient programs in HPLC on the basis of isocratic TLC data. The proposed method has many advantages and can also be used in reversed-phase systems. A satisfactory agreement between the theoretical and experimental of V_R/V_O values has been confirmed. Some discrepancies for more strongly retained solutes are, probably due to the respective equilibrium and nonequilibrium state of the column in isocratic and gradient elution.Part I: Ref. [1].     

Exhibition of the first gas chromatographic work of Erika Cremer and Fritz Prior

Summary In November 1995, theDeutsches Museum, the world's largest technical museum, opened a new branch in Bonn, devoted to achievements after 1945. There, the first gas chromatographic system used by Erika Cremer and Fritz Prior, in 1945–47, in Innsbruck, is exhibited. The new display is described and the early activities of Erika Cremer and her students are summarized.     

茶多酚的色谱分析法

 对茶多酚的主要成分――儿茶素的色谱分析法进行了综述。重点介绍了应用最多的反相高 效液相色谱法,同时简述了平板色谱法、气相色谱法以及目前出现的新的色谱分析方法。     

Affinity monolith chromatography: A review of general principles and recent developments

Affinity monolith chromatography (AMC) is a liquid chromatographic technique that utilizes a monolithic support with a biological ligand or related binding agent to isolate, enrich, or detect a target analyte in a complex matrix. The target-specific interaction exhibited by the binding agents makes AMC attractive for the separation or detection of a wide range of compounds. This article will review the basic principles of AMC and recent developments in this field. The supports used in AMC will be discussed, including organic, inorganic, hybrid, carbohydrate, and cryogel monoliths. Schemes for attaching binding agents to these monoliths will be examined as well, such as covalent immobilization, biospecific adsorption, entrapment, molecular imprinting, and coordination methods. An overview will then be given of binding agents that have recently been used in AMC, along with their applications. These applications will include bioaffinity chromatography, immunoaffinity chromatography, immobilized metal-ion affinity chromatography, and dye-ligand or biomimetic affinity chromatography. The use of AMC in chiral separations and biointeraction studies will also be discussed.