scholarly journals Giving preparative thin layer chromatography some tender loving care

Author(s):  
John Hayward ◽  
Lavleen Mader ◽  
John Trant

Preparative thin layer chromatography (prepTLC) is a commonly used method of purification suitable for small scale reactions. However, descriptions of the preferred methodology to load, run, and recover samples from prepTLC are non-standard and varied, making it part of the “hidden curriculum” of laboratory technique. In this article we report on the simple, cost-effective methods we use to load and collect samples from a plate, which enhance the convenience, speed, and precision of this technique.

2018 ◽  
Vol 1 (1) ◽  
pp. 264-270
Author(s):  
Hady Wiraputra ◽  
Marline Nainggolan ◽  
Panal Sitorus

Tanaman buni (Antidesma bunius (L.) Spreng.) secara tradisional telah digunakan untuk hipertensi, takikardia, anemia, sifilis, antikanker, antioksidan, sumber pewarna alami dan antidiabetes. Saponin merupakan senyawa fitokimia yang mempunyai kemampuan membentuk busa dan mengandung aglikon polisiklik yang berikatan dengan satu atau lebih gula. Penelitian ini bertujuan untuk melakukan karakterisasi senyawa saponin hasil isolasi dari daun buni dengan spektrofotometer ultraviolet dan inframerah. Simplisia daun buni dilakukan karakterisasi kemudian diekstraksi dengan cara maserasi bertingkat menggunakan pelarut n-heksana dan etanol 80%. Selanjutnya ekstrak etanol dihidrolisis dengan HCl 2N kemudian difraksi dengan pelarut kloroform. Isolasi dilakukan terhadap fraksi kloroform dengan cara kromatografi lapis tipis preparatif menggunakan fase diam silika gel GF254 dan fase gerak yang sesuai. Isolat yang diperoleh diuji kemurnian dengan KLT 2 arah dan dikarakterisasi menggunakan spektrofotometer ultraviolet dan inframerah. Hasil pemeriksaan karakterisasi simplisia diperoleh kadar air 7,32%, kadar sari larut dalam etanol 52,70%, kadar sari larut dalam air 23,25%, kadar abu total 6,86% dan kadar abu tidak larut dalam asam 0,94%. Pemisahan fraksi kloroform dengan KLT menggunakan fase gerak n-heksana-etilasetat perbandingan 5:5 diperoleh noda 13 dan hasil KLT preparatif diperoleh 2 isolat murni yaitu isolat 1 (ungu merah) dengan Rf 0,92 dan isolat 2 (biru) dengan Rf 0,78. Hasil karakterisasi isolat 1 diperoleh panjang gelombang maksimum pada 208 nm dan dijumpai adanya gugus hidroksil, gugus -CH alifatis, ikatan C=C, gugus –CH2, gugus –CH3, dan gugus C-O. Hasil karakterisasi isolat 2 diperoleh panjang gelombang maksimum pada 204 nm dan adanya gugus hidroksil, gugus -CH alifatis, gugus –CH2, gugus –CH3, dan gugus C-O. Buni (Antidesmabunius (L.) Spreng.) has been traditionally used for the treatment of hypertension, tachycardia, anemia, syphilis, and used asanti-cancer, anti-oxidant, natural dye, and anti-diabetic. Saponin is a phytochemical compound which has capability in forming foam and contains polycyclic aglycone that binds with one or more glucose. This research aimed to conduct the characterization of saponin compound from buni leaves with ultraviolet spectrophotometer and infrared. Buni leaves simplicia was characterizedand extracted using sequential maceration method with n-hexane and 80% ethanol. The ethanol extract was hydrolyzed with HCl 2N and fractionized using chloroform solvent. Isolation of chloroform fraction was done using preparative thin-layer chromatography using silent phase of silica gel GF 254 and suitable mobile phase. Isolates obtained was taken into purity test with two dimensions thin-layer chromatography and characterized using ultraviolet spectrophotometer and infrared. The characterized simplicia resulted with 7.32% of water content, 52.70% of dissolved content in ethanol, 23.25% of dissolvedcontent in water, 6.86% of total ash content, and 0.94% of undissolved ash content in acid. Fractinationof chloroform fraction with thin-layer chromatography using mobile phase ofn-hexane-ethyl acetate with 5:5 ration resulted with 13 spotsand the result of the preparative thin-layer chromatography resulted 2 pure isolates which are isolate 1 (purple-red) with Rf 0.92 and isolate 2 (blue) with Rf 0.78. The characterization of isolate 1 resulted that the maximum wave lengthwas 208 nm with hydroxyl group, –CH aliphatic group, C=C bond, –CH2 group, –CH3 group, and C–O group. The characterization of isolate 2 resulted that the maximum wave lengthwas204 nm with hydroxyl group, –CH aliphatic group, –CH2 group, –CH3 group, and C–O group.


1967 ◽  
Vol 50 (4) ◽  
pp. 934-938
Author(s):  
Paul E Corneliussen

Abstract A rapid method for determining biphenyl in citrus fruits has been developed and was studied collaboratively. Biphenyl is separated from fruit tissue by steam liquidliquid extraction. The ra-heptane extract is subjected to preparative thin layer chromatography (TLC) on plates coated with silica gel containing phosphors for ready visibility of the biphenyl spots under UV light. The spots are removed from the plate and extracted with alcohol for spectrophotometric measurement at 248 mμ. The TLC cleanup adds specificity to the method; o-phenylphenol, if present, does not interfere and crop blanks are insignificant. The average of 36 recoveries (12 each at abovit 100, 50, and 10 ppm) was 96.7% with a mean deviation of 10.7%. It is recommended that the method be adopted as official, first action.


Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 938 ◽  
Author(s):  
Emily Amor Stander ◽  
Wesley Williams ◽  
Fanie Rautenbach ◽  
Marilize Le Roes-Hill ◽  
Yamkela Mgwatyu ◽  
...  

Aspalathin, the main polyphenol of rooibos (Aspalathus linearis), is associated with diverse health promoting properties of the tea. During fermentation, aspalathin is oxidized and concentrations are significantly reduced. Standardized methods for quality control of rooibos products do not investigate aspalathin, since current techniques of aspalathin detection require expensive equipment and expertise. Here, we describe a simple and fast thin-layer chromatography (TLC) method that can reproducibly visualize aspalathin in rooibos herbal tea and plant extracts at a limit of detection (LOD) equal to 178.7 ng and a limit of quantification (LOQ) equal to 541.6 ng. Aspalathin is a rare compound, so far only found in A. linearis and its (rare) sister species A. pendula. Therefore, aspalathin could serve as a marker compound for authentication and quality control of rooibos products, and the described TLC method represents a cost-effective approach for high-throughput screening of plant and herbal tea extracts.


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