The chemical constituents of herbal products may vary depending on harvest seasons, plant origins, drying processes and other factors. Thus, it is necessary to determine phytochemical constituents of herbal products in order to ensure reliability and repeatability of their pharmacological and clinical effect. Several chromatographic techniques, such as high-performance liquid chromatography (HPLC), gas chromatography (GC), high-pressure thin layer chromatography (HPTLC) can be applied to quantify the major components of the herbal products. They also can be used to prepare a chemical profile, such as a chromatographic fingerprint, for an herbal product which can be compared with the profile of a standard reference.  They also can be used to detects different adulterations and any unwanted ingredients.  

Thin layer chromatography (TLC), High-pressure thin layer chromatography (HPTLC)

TLC and HPTLC are usually the common methods of choice for herbal analysis before establishing other instrumental chromatographic methods such as GC and HPLC. Several herbal pharmacopeias have provided TLC fingerprints of herbal medicines. TLC is rather simple and can be employed for multiple sample analysis. For each chromatography lane, more than 40 compounds can be separated simultaneously at one time. It is possible to obtain useful qualitative and quantitative information from the developed HPTLC plate.

Gas chromatography (GC) and volatile components in herbal medicines

It is well-known that many pharmacologically active components of herbal medicines are volatile chemical compounds. Thus, analysis of volatile compounds by gas chromatography is very important in the analysis of herbal products. GC analysis of volatile oils gives a reasonable “fingerprint” which can be used to authenticate essential oils. The composition and relative concentration of the organic compounds in the volatile oil are characteristic of the particular plant and the presence of impurities in the volatile oil can be readily detected. Secondly, the extraction of the plants' volatile oil is relatively straightforward and their components can be easily identified using GC–MS. The advantage of GC clearly is its high sensitivity of detection for almost all the volatile chemical compounds. This is especially true for the usual GC-FID detection and GC–MS.

High-performance liquid chromatography

HPLC is a popular method for the analysis of herbal products because it is easy to learn and use and is not limited by the volatility or stability of the sample compound. In general, HPLC can be used to analyze almost all the compounds in the herbs. It is necessary to notice that the optimal separation condition for the HPLC involves many factors, such as the different compositions of the mobile phases, their pH adjustment, pump pressures, etc. Thus, a good experimental design for the optimal separation is necessary. The advantages of HPLC is its versatility for the analysis of the chemical compounds in herbal medicines.

Atomic absorption is used to determine heavy metal contaminations of herbal products.

During this Short-Term Training Program, each student will have a practical project on quality control of herbal medicine/ natural product. Meanwhile, he/she will attend the necessary classes on theoretical bases of the experimental procedure as well as the instrumental techniques. The students will learn about determining Pharmacopeial values for herbal medicine as well as working with GC/MS; HPTLC; HPLC; IR and atomic absorption. The student is required to finish the project and give a report as a manuscript with final data.

This project does not include troubleshooting or repairing the instruments.

To see more information on this program please click here.