Quality control of Chinese herbal medicine with chemical marker analysis by GCxGC-MS

Worldwide traditional Chinese medicine (TCM) has become more and more popular as alternative to western medicine in the last decades, especially in Europe and the USA. Drug therapy with nearly 90 % of medicinal Chinese plants is the heart of TCM and has the most influence on health of all therapeutic TCM methods. Besides, these plants can be a good source for new pharmaceutical substances and for the treatment of chronic illnesses like cardiovascular disease or pain. Lots of written notes of the medicinal experiences during the last 2000 years can support this research and development.

However, the prevalent problems with TCM drugs are adulteration and confusion of the herbs. At the worst this can cause adverse effects for human health because of toxic or carcinogenic ingredients (e. g. aristolochic acid) in a single drug. Hence, for the safety of the patients it is very important to develop a quality control which guarantees the correct composition and the potency of herbal formulas. Because these samples present very complex compositions, it is necessary to analyse them with the use of high-performance analytical methods, e. g. GCxGC-MS, which can be combined with the detection of specific chemical markers and fingerprints of the herbs as useful tools. Chemical markers for a lot of medicinal drugs do not even exist today or have not yet been sufficiently determined for the differentiation of unequal herbs and for a successful quality control.

In our work we could demonstrate that GCxGC-MS is a very powerful method to distinguish powders of different Angelica species, to differentiate between high and low qualities of Chinese mint herb (Herba Menthae haplocalycis) and to discover potential new chemotypes of herbal species.

Work was done by Alexandra von Trotha