All Things Chromatography

HPLC reveals difference between freshly brewed and bottled tea

Our friends at Chromatography Today published an Joe Tea resized 600interesting finding recently about how HPLC has been used to examine the chemical differences between fresh-brewed tea and bottled tea.

Here's an excerpt:

Dr Shiming Li, a natural product chemist at New Jersey biotechnology firm WellGen, led a team using HPLC to analyse polyphenol levels in fresh tea and in bottled health drinks.

In some cases, the bottled beverages had levels of the antioxidants equivalent to around five per cent of the quantity seen in a single freshly brewed cup of either green or black tea.

Click Here to read more from Chromatography Today.

Topics: HPLC, testing, test

Thin Layer Chromatography used to clear fish in India

The fishing ban put in place after an oil tanker collision off fishing in Indiathe coast of India has been lifted after Thin Layer Chromatography tests on 138 samples revealed no trace of oil.

Here's excerpts from the Hindustan Times:

On August 10, three days after the collision, the Brihanmumbai Municipal Corporation had taken 138 samples of local varieties of fish such as mandeli, red prawns and Bombay duck from 30 civic markets and tested them.

The Thin Layer Chromatography (TLC) test on these samples, conducted at the National Institute of Oceanography and a private institute, showed no traces of oil. “No trace of oil has been found on any of the samples. But fish-eaters should be cautious,” said Deepak Kamat, assistant municipal commissioner, markets department.

Click Here to read the complete article.

Topics: TLC, Thin Layer Chromatography, testing, test

Thin Layer Chromatographic Analysis of Counterfeit Drugs

Joseph Sherma is the John D. and Frances H. Larkin Professor Emeritus of Chemistry at Lafayette College, Easton, Pennsylvania. Professor Sherma has taught courses in analytical chemistry for more than 40 years, was head of the chemistry department for 12 years, and continues to supervise research students at Lafayette College. He is author and coauthor of over 600 papers and the author, coauthor, editor, and coeditor of over 60 books and manuals in the areas of analytical chemistry and chromatogEncyclopedia of Chromatographyraphy.

Professor Sherma recently authored the article, "Thin Layer Chromatographic Analysis of Counterfeit Drugs" - which is featured in the Encyclopedia of Chromatography, Second Edition.

Here's a look at the Abstract:

Economical and reliable thin layer chromatographic (TLC) methods for rapid screening of counterfeit drugs that can be carried out by analysts in the laboratory or in the field by inspectors with limited analytical expertise using portable kits, with standard reference tablets to eliminate weighing, are described. Separations are performed on silica gel layers containing fluorescent indicator; separated spots are detected under ultraviolet lamps and with iodine detection reagent. Development and iodine detection are carried out in polyethylene bags, glass jars, or closed TLC tanks. Sample spots are compared with reference standards developed on the same layer to identify the ingredients and determine if their content is within the specification range.

Click Here to find out how to obtain the paper.

Topics: Sherma, Thin Layer Chromatography, testing, test

Thin Layer Chromatography used to detect counterfeit medication in India

Excerpts from a research article published at Plosone.org:TLC Chart

Pilot Study of Essential Drug Quality in Two Major Cities in India

India is an increasingly influential player in the global pharmaceutical market. Key parts of the drug regulatory system are controlled by the states, each of which applies its own standards for enforcement, not always consistent with others. A pilot study was conducted in two major cities in India, Delhi and Chennai, to explore the question/hypothesis/extent of substandard and counterfeit drugs available in the market and to discuss how the Indian state and federal governments could improve drug regulation and more importantly regulatory enforcement to combat these drugs.

Random samples of antimalarial, antibiotic, and antimycobacterial drugs were collected from pharmacies in urban and peri-urban areas of Delhi and Chennai, India. Semi-quantitative thin-layer chromatography and disintegration testing were used to measure the concentration of active ingredients against internationally acceptable standards. 12% of all samples tested from Delhi failed either one or both tests, and were substandard. 5% of all samples tested from Chennai failed either one or both tests, and were substandard.

Read the entire research paper by clicking here.

Topics: malaria, anti-malarial, Thin Layer Chromatography, testing, test

Thin Layer Chromatography to detect nicotine

This one continues to demonstrate the broad scope of smokingapplications for Thin Layer Chromatography - and shows again that you never know where TLC will show up in the media.

GoodEveningWorld.com bills itself as an "Online Magazine covering Fashion, Beauty, Celebrity Buzz, Health Care, Pregnancy & Parenting, Love, Home and Relationships"

The site has just posted a comprehesive overview of smoking tobacco and includes this portion about detecting nicotine:

Diagnosis of Smoking (presence of nicotine)

Traces of nicotine can be found in urine for nearly 3 days after the last smoke, so a urine test can be carried out which gives qualitative results for nicotine.

Thin layer chromatography (TLC): In this test, mixtures are separated by using an absorbent material like aluminum oxide or silica on testing sheets.

 To read the whole post, click here.

 

Topics: Thin Layer Chromatography, testing, test, smoking, nicotine

Thin Layer Chromatography used to weed out counterfeit medication

We've posted on this subject before, but wanted to offer fake drugsmore on the subject from our friends at Australia's On Line Opinion, where Roger Bate has written about tools to fight fake drugs:

Poor quality medicines are pervasive across Africa. The WHO reports that more than 30 per cent of medicines on sale in many African countries are counterfeit, with some pills containing nothing more than chalk or water.

The German Pharma Health Fund's “Minilab” uses thin layer chromatography, disintegration and simple dye tests to help weed out the worst-quality products. Generally, a product will “pass” the Minilab test if it contains 80 per cent or more of the labelled active ingredient.

 Click Here to read the entire piece.

 

Topics: malaria, chromatography, Thin Layer Chromatography, testing, test

Thin Layer Chromatography used in DNA aging research

Excerpts from a paper posted on the U.S. National Library of Medicine and the National Institutes of Health web site DNA strandstitled:

TLC-based detection of methylated cytosine: application to aging epigenetics

5-Methylcytosine (m(5)C) has a plethora of functions and roles in various biological processes including human diseases and aging. A TLC-based fast and simple method for quantitative determination of total genomic levels of m(5)C in DNA is described, which can be applicable to aging research with respect to rapid and high throughput screening and comparison. Using this method, an example of the analysis of global alternations of m(5)C in serially passaged human skin fibroblasts is provided, which shows age-related global hypomethylation during cellular aging in vitro.

Click Here to access the paper.

Topics: National Institutes of Health, chromatography, Thin Layer Chromatography, testing, test, DNA, aging, NIH

CDC recommends Thin Layer Chromatography to test anti-malarial drugs

The U.S. Centers for Disease Control and Prevention advise that, "Counterfeit (fake) drugs are products deliberately made to resemble a brand name pharmaceutical. They may contain no active ingredients or contain ingredients inconsistent with the package description."
Malaria treatment
For example, the CDC says, "In Cambodia in 1999, counterfeit antimalarial drugs were responsible for the deaths of at least 30 people. A recent survey in Southeast Asia showed that among 104 tablets presented as the antimalarial drug artesunate, 38% did not contain any artesunate."

Users of pharmaceutical products (not only antimalarials) should take the following precautions:

  • Travelers should purchase in advance, in their home country, all the medicines they will need.
  • Travelers should record the drug's generic and brand names as well as the name of the manufacturer; should they run out, they can look for the correct product.
  • Make sure that the drug is in its original packaging.
  • Inspect the packaging because many times poor quality printing indicates a counterfeited product.
  • Be suspicious of tablets that have a peculiar odor, taste or color, or that are extremely brittle.

The CDC recommends testing suspicious drugs.

"drug quality can be evaluated in the field by two simple, effective, and low-cost techniques: thin-layer chromatography (TLC) and colorimetry... The TLC technique consists of placing a spot of drug sample on a thin layer of silica attached to a plate of glass, aluminum, or plastic. The plate is then inserted into a vessel containing a solvent mixture. By capillary action, the solvent mixture creeps up the silica material and dissolves the sample. The drug sample consists of a mixture of drug and inactive ingredients. These compounds will have various affinities to the silica matrix and will migrate with the solvent at various speeds. This characteristic effectively separates out a mixture of compounds. After migration of the solvent is complete, individual components can be visualized by chemical treatment or ultraviolet (UV) absorbance. The distance that the components migrate is characteristic for each compound; therefore the active ingredient can be recognized by comparison with a known drug standard. The solvent can be modified to increase resolution between various components. This method is relatively inexpensive, specific, and sensitive. It is commonly used to assess drug quality."

Click Here for more details from the CDC.

Click Here to find out more about Thin Layer Chromatography plates and accessories.

Topics: Separation, malaria, anti-malarial, Thin Layer Chromatography, testing, test

More details on swine flu and testing with chromatography

Following yesterday's post about swine flu testing with chromatography, there's been numerous articles, posts, and papers offered up about the swine flu break out.swine flu vaccine

We've compiled some of these here, and invite you to keep us informed of anything you come across that may be of interest - simply submit your material below.

First, for all of the latest from the Centers for Disease Control and Prevention on the swine flu, click here.

For information about how Thin Layer Chromatography is used to detect counterfeit pharmaceuticals, including Tamiflu, click here.

For an article from TheScientist.com about biotech's response to swine flu, click here.

For an article from the Wall Street Journal about the need for rapid tests, click here.

Topics: Swine Flu, Thin Layer Chromatography, testing, test, CDC, Tamiflu

Chromatography used for testing Swine Flu

UPDATE: Article from TheScientist.com - Can biotech tackle swine flu? - click here to read

For decades, scientists have been using Thin Layer Chromatography, HPLC, gas, and other forms of chromatography to study swine influenza.

Scientists working on swine fluHere is just one example. In October of 1985, a team from the Department of Neurology at The Medical University of South Carolina published "Lipid content of swine influenza and other vaccines" - here's a couple of excerpts:

ABSTRACT: An analysis of the lipids in swine influenza vaccines was performed, comparing six different lots of swine influenza, other influenza and noninfluenza vaccines.
Cholesterol content and phospholipid content varied greatly, but there were no major differences between the types of vaccines. Appreciable amounts of phosphatidylethanolamine were found in only one swine influenza vaccine. The major phospholipids of influenza vaccines were phosphatidylcholine, sphingomyelin and phosphatidic acid. A detectable amount of phosphatidylserine was not found in any swine influenza vaccine, but was present in two of three nonswine influenza vaccines. Only two of six swine influenza vaccines showed trace amounts of ganglioside. However, larger quantities of galactocerebroside were found in all
influenza vaccines examined, including swine influenza vaccines.

...

Neutral lipids were separated on silica gel thin layer chromatography (TLC) plates developed in light petroleum ether/diethyl ether (96:4, v/v) and visualized by exposure to iodine vapors.
Phospholipids were separated by two-dimensional TLC using high performance TLC (HPTLC) plates. After application, samples were chromatographed in C/M/concentrated ammonia (65:35:5, v/v/v) to the top of the plate plus an additional 10 min. HPTLC plates were air-dried and held in vacuo overnight over P205 to reactivate the silica gel. Chromatography in the second direction was performed in chloroform/acetone/methanol/acetic acid/water (5:2:1:1:0.5, v/v/v/v/v). After being air-dried, phospholipids were visualized by exposure to iodine vapors, matched to standards and marked. After sublimation of I2, marked areas were carefully scraped from the glass backing, charred and assayed for liberated phosphate by the method of Ames {27}. Prior to TLC, aliquots were withdrawn and assayed in the same manner for total phospholipid determination.

 Click Here to Access the complete paper.

Click Here to learn more about high quality Thin Layer Chromatography plates and accessories.

Topics: Scientist, Swine Flu, chromatography, testing, test