Category Archives: test

HPLC reveals difference between freshly brewed and bottled tea

Our friends at Chromatography Today published an Joe Tea resized 600 interesting 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.

Latest Technology for Training in the Medical Field

UPDATE: New Video just released on this program:

Our company is fortunate to be involved with the Delaware Virtual hospital BioScience Association BioScience Association and the Technology Forum of Delaware – both organizations have held events at Christiana Care where we have been able to tour a newly opened virtual training hospital.

This training area is designed to mimic everything from an Emergency Room to an Operating Room to a Delivery Room where entire medical teams are put in situations and practice techniques and procedures on the very life-like “patients” (some of them have pulses, talk, and even change skin color if they are not getting enough oxygen).

Here’s a look at the hospital from the WHYY TV Program “First”

Watch the full episode. See more First.

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 chromatog Encyclopedia of Chromatography raphy.

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.

Thin Layer Chromatography and HPLC featured in quality standards for Dietary Supplements

The U.S. Pharmacopieal (USP) Convention has just released a first-of-its kind collection of standards designed to assist dietary supplements manufacturers in providing quality products to consumers.

The USP Dietary Supplements Compendium (DSC) is a comprehensive resource containing quality specifications (identity, strength, purity, and performance characteristics) of more than 500 dietary supplements and ingredients. In addition to these standards, the DSC includes general and regulatory information, guidance documents, appendices, and macro/microscopy, thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) full-color images that greatly simplify the analysis of ingredients of botanical origin—making it a central repository of necessary information for dietary supplements manufacturers.

The DSC serves as a tool for manufactures in:

Developing, manufacturing and testing new products;
Qualifying raw materials;
Preparing for international quality control and cGMP audits;
Setting and validating standard operating procedures;
Collecting in-process and batch-release tests; and
Accurately packaging, labeling and storing products.

Click Here for more information from USP.

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.

An Apple A Day – minus the patulin – how Thin Layer Chromatography provides faster, cheaper answers

Here’s an excerpt from Scirus.com about using Thin Layer apple with patulin Chromatography for the analysis of patulin in apple juice (emphasis added) :

Researchers from Brazil developed a rapid, simple and economical method using thin-layer chromatography quantification via fluorescence images from a UV lamp, for the determination of patulin in apple juice concentrate

Why it matters

According to the authors, patulin is a mycotoxin produced by certain species of Penicillium, Aspergillus and Byssochlamys. In previous research studies, liquid chromatography has been used for patulin determination in clear and cloudy apple juices, apple puree and apple-based products intended for infants. Methods such as gas and liquid chromatography have very low detection limits, but both techniques require sophisticated and costly equipment, extensive cleanup procedures and high purity solvents. Thin-layer chromatography (TLC) is a fast, cheap and efficient method of separation and identification of many mycotoxins. By coupling a two-dimensional charge coupled device with thin-layer chromatography, the entire TLC can be imaged in a single exposure, yielding rapid quantification in shorter analysis time than slit scanning densitometers.

Click Here for the full Abstract.

Thin Layer Chromatography used to weed out counterfeit medication

We’ve posted on this subject before, but wanted to offer more 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.

Thin Layer Chromatography used in plant defense research

Anti-herbivore Structures of Paulownia tomentosa: Morphology, Distribution, Chemical Constituents and Changes During Shoot and Leaf Development:

Background and Aims: Recent studies have shown that small structures on plant surfaces serve ecological functions such as resistance against herbivores. The morphology, distribution, chemical composition and changes during shoot and leaf development of such small structures were examined on Paulownia tomentosa.

Methods: The morphology and distribution of the structures were studied under light microscopy, and their chemical composition was analysed using thin-layer chromatography and high-performance liquid chromatography. To further investigate the function of these structures, several simple field experiments and observations were also conducted.

Click Here to read more.

Doing Thin Layer Chromatography at home

Sean Michael Ragan at Makezine.com recently posted a great post about Thin Layer Chromatography in the kitchen – here’s some excerpts:

During my six-odd years as a graduate organic chemist, probably the cheapest, most powerful, and most commonly used analytical laboratory technique in my bag of tricks was thin-layer chromatography…

[another] common reason for performing separations is analytical: You want to get an idea of how many compounds are in there and whether or not one of them is compound “X.” Thin-layer chromatography lets you do this, on a bench-top, with a few cents worth of materials and a few minutes of time. It’s unbelievably powerful for such an inexpensive technique.

Click here to read the complete post.

Thin Layer Chromatography and Ophthalmology

This bit of insight comes from our friends at Medical Blog.

A variety of genetic, metabolic, developmental, and idiopathic causes can result in congenital clouding of the cornea. A common reason for congenital clouding of the cornea is congenital glaucoma. Other major causes of corneal clouding include the following: Birth trauma Peters anomaly Dermoid tumors (limbal dermoids) Sclerocornea Congenital hereditary endothelial dystrophy (CHED) Mucopolysaccharidoses Infectious/inflammatory processes The following is a mnemonic for the causes of congenital clouding of the cornea: S – Sclerocornea T – Tears in the Descemet membrane secondary to birth trauma or congenital glaucoma U – Ulcers M – Metabolic P – Peters anomaly E – Edema (CHED) D – Dermoid Other rarer causes of congenital clouding of the cornea include the following: cornea plana, corneal keloids, oculoauriculovertebral (OAV) dysplasia (Goldenhar-Gorlin syndrome), congenital corneal ectasia, congenital hereditary stromal dystrophy, posterior polymorphous dystrophy, and Fryns syndrome.

…

A 4-month-old male infant had severe corneal opacity since birth. Examination revealed buphthalmos, increased IOP, and corneal opacity with neovascularization but not a dysmorphic face or hirsutism. The liver and spleen were impalpable. Hypotonia, poor head control, and absence of Moro and grasping reflexes were noted. He had no evidence of congenital infection (toxoplasmosis, other infections, rubella, cytomegalovirus infection, and herpes simplex [TORCH] study). Urine and plasma amino acid levels were normal. However, thin-layer chromatography showed excessive urinary excretion of heparan sulfate. Corneal transplantation was performed at 6 months of age. Histopathology of the corneal button showed homogeneous thickening of the Bowman layer and pinkish intracytoplasmic substances in the corneal stroma. The Alcian blue stain was positive, consistent with MPS of the cornea.

Click Here to read the full report.

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