Mobile-Phase Velocity — a Tool for Separation of Alkaloids by OPLC

JPC – Journal of Planar Chromatography – Modern TLC - Extracts of tertiary and quaternary alkaloids from Chelidonium majus L. have been separated by OPLC. Samples of different volumes...     

Separation and Quantitative Determination of Aldoses and Alditols by Over-Pressured Layer Chromatography (OPLC)

JPC – Journal of Planar Chromatography – Modern TLC - Anew OPLC method has been established for separation and quantitative determination of three alditols (d-xylitol, L-arabitol, and...     

Overpressured Layer Chromatographic (OPLC) Separation of Closely Related Furocoumarins

Abstract

In this paper, an OPLC method for the analytical separation of eight furocoumarins is described. Of the eight compounds investigated, four are linear furocoumarins (psoralen, bergapten, 8-methoxypsoralen, iso-pimpinellin) and four are angular furocoumarins (angelicin, sphondin, iso-bergapten, pimpinellin). In preliminary experiments, optimization of the mobile phase was made using the “PRISMA” model on TLC plates in unsaturated chambers. Evaluation of the final optimization steps for OPLC separations on HPTLC plates was done densitometrically. With the elaborated OPLC system, seven compounds could be baseline separated, and the resolution between iso-bergapten and angelicin was better than 1.3. Application of the method is demonstrated with the analysis of furocoumarin-containing root extracts from Heracleum sphondylium, H. mantegazzianum and Pastinaca sativa.     

Separation and identification of cannabis components by different planar chromatography techniques (TLC, AMD, OPLC)

The use of cannabis is illicit in numerous countries, and the increasing consumption has led to a multiplication of scientific studies. New methods of planar chromatography such as automated multiple development (AMD) and optimum performance laminar chromatography (OPLC) techniques can be used as a substitute for the traditional thin-layer chromatography for the identification and quantitation of the Indian hemp components. Each method offers its own advantage: high resolution with neither diffusion nor spot stretching for AMD and speed, efficiency, and the possibility of working in the semipreparative mode for OPLC.     

Fumonisins determination in urine by LC-MS-MS

The present work shows the optimization and validation results of an analytical methodology based on imunoaffinity clean-up (IAC) followed by liquid chromatography with tandem mass detection (LC-MS-MS) for the analysis of the mycotoxins fumonisin B₁ (FB₁) and B₂ (FB₂) in human urine samples, in order to evaluate fumonisins exposure in two Portuguese populations. As far as we know, imunoaffinity clean-up procedure was used, for the first time, in the analysis of fumonisins (FBs) in urine. Using this analytical methodology, the limit of quantification achieved was 10 ng mL⁻¹ for FB₁ and for FB₂. Recoveries were higher than 73.4% for fortification levels between 10 and 100 ng mL⁻¹ and intra-day and inter-day repeatibility were lower than 8.6%. The natural occurrence of FB₁ and FB₂ in 68 human urine samples obtained from the central zone of Portugal was studied. None of the studied samples presented detectable levels of FB₁ and FB₂.     

Optimization of the Visualization of Steroids Separated by OPLC

JPC – Journal of Planar Chromatography – Modern TLC - The acidic visualization methods most often used for steroids have been optimized and compared. Sulfuric acid at three different...     

Use of the BioArena System for Indirect Detection of Endogenous Ozone in Spots after TLC or OPLC Separation

JPC – Journal of Planar Chromatography – Modern TLC - Singlet oxygen (1O2)-catalyzed oxidation of water leads to a variety of oxidants (e.g. ozone, O3) in host–parasite...     

Biochemical Examination of the General Defense System of Plants by OPLC

JPC – Journal of Planar Chromatography – Modern TLC - Plant resistance breeding has, so far, been based on specific resistance genes which regulate hypersensitive reaction, resulting in...     

Increased Detection Sensitivity in Fully Off-Line OPLC by Bilateral Band Compression

JPC – Journal of Planar Chromatography – Modern TLC - A new process, bilateral band compression has been used to increase the sensitivity of detection of minor components of a mixture....     

Isolation of Some Antimicrobial Compounds of Red Wine by OPLC Flowing Eluent Wall Technique

The first results of the combination of BioArena and OPLC with flowing eluent wall technique (FEW) show an especially attractive solution of the detection of antimicrobial activity and compound isolation based on peak collection. Because of the different separation mechanisms applied for on-line FEW–OPLC isolation of red wine constituents and for further off-line OPLC investigation of fractions, the combined system yields high selectivity.     

Fully On-Line Hyphenation of an Experimental OPLC Separation Unit with Diode-Array Detection and Mass-Spectrometry (OPLC-DAD-MS) for Analysis of Xanthine Compounds

JPC – Journal of Planar Chromatography – Modern TLC - The newly developed experimental OPLC separation unit 100 (OSU 100) has been used for fully on-line multiple hyphenation using the...     

免疫亲和柱净化-柱前衍生-高效液相色谱法测定中药薏苡仁中的伏马毒素

建立了免疫亲和柱净化-自动化柱前衍生-高效液相色谱测定中药薏苡仁中伏马毒素(FB1、FB2、FB3)的分析方法.样品经甲醇-乙腈-水(1∶ 1∶2)振荡提取,免疫亲和柱净化,采用 自动化柱前衍生-高效液相色谱测定FB1、FB2、FB3.结果表明:FB1、FB2、FB3在5～200 ng/mL之间线性关系良好,相关系数均...     

OPLC of Carbohydrate Content for Quality Control of Commercial Romanian Wines

JPC – Journal of Planar Chromatography – Modern TLC - Arapid and simple method for simultaneous quantitative analysis of the natural carbohydrates fructose, glucose, and sucrose in...     

Chromatographic Evaluation of the Lipophilicity of N-Phenyltrichloroacetamide Derivatives using Micellar TLC and OPLC

JPC – Journal of Planar Chromatography – Modern TLC - Micellar liquid chromatography (MLC) has been used to study the lipophilicity of eight newly synthesized N-phenyltrichloroacetamide...     

Overpressured layer chromatography (OPLC)--a flexible tool of analysis and isolation

This review briefly summarizes the overpressured layer chromatography (OPLC) technique and its progress from the beginning until today. Some theoretical aspects, important technical and methodological solutions, as well as analytical separations and isolations are demonstrated covering the last 30 years. The infusion and transfusion OPLC operations, as well as their combination, and their off-line and on-line processes, and off-line and on-line hyphenations for detection and structure elucidation are presented. The combination of OPLC separation with biological detection by direct bioautography and BioArena as an important solution touches the potential of analysis and isolation based on biological activity.     

液相色谱-串联质谱法测定粮谷中的伏马毒素

建立了液相色谱-串联质谱同时测定玉米、小麦、大米和黄豆中伏马毒素FB1、FB2的分析方法。样品经甲醇-水-乙酸(74∶25∶1)提取,强阴离子交换柱(SAX)净化后,以0.1%乙酸水溶液-乙腈为流动相,ZORBAX Extend-C18反相色谱柱(150 mm×2.1 mm,1.8 μm)进行色谱分离,在电喷雾正离子化模式下,选择反应监测(SRM)方式进行测定。结果表明：FB1和FB2分别在2.5~1 000、5.0~1 000 μg/L范围内线性关系良好,相关系数分别为0.999 5和0.999 7。对4种空白基质分别进行0.02、0.50、2.00 mg/kg 3个水平的加标回收实验,FB1和FB2的加标回收率分别为67.5%~90.5%和70.5%~95.3%,相对标准偏差(RSD)分别为1.3%~11.4%和1.5%~10.6%,检出限分别为2.00 μg/kg和4.00 μg/kg。该方法稳定、可靠,适用于谷物中FB1和FB2的同时检测与确证。     

OPLC Investigation of the Effect of Cold-hardening on the Level of Polyamines in Wheat

JPC – Journal of Planar Chromatography – Modern TLC - The effect of cold-stress (2°C, 7 days cold-hardening) on the level of polyamines in different varieties of wheat and...     

OPLC and HPTLC methods in physicochemical studies of a new group of antimycotic compounds

In this study two high-performance methods [overpressured layer chromatography (OPLC) and high-performance thin-layer chromatograpy (HPTLC) under reversed-phase conditions] are used to evaluate the hydrophobicity properties of newly synthesized bioactive compounds. The retention behavior of 24 2-(2,4-dihydroxyphenyl)benzothiazoles are examined for acquisition of log k data. With water-methanol mixtures as the mobile phases, the concentration range in which the correlation between log k and methanol content is linear is established for both methods and used to determine the hydrophobicity parameters of log kw by linear extrapolation. The effect of substituents on retention constants is quantitated by using the group contribution parameters (tauw). The results suggest the use of OPLC methods for quick analysis of physicochemical properties of a large number of organic compounds.