By Mark Jacyno, Melissa Wilcox, and Linda Xu
Traditional Chinese medicines have played an important role in clinical therapy and have been attracting more and more attention for their complementary therapeutic effects to western medicines with low toxicity and few to no complications. With the use of traditional herbal medicines gaining popularity worldwide, the questions of purity and safety of these supplements or natural products have become a concern for public health authorities. The FDA, WHO, and the Chinese Pharmacopoeia have begun generating reliable and accurate analytical techniques to standardize quality control in manufacturing of these supplements to insure the correct identity, authenticity, and lot to lot consistency.
As many of the novel active compounds in these supplements are non-chromophoric, evaporative light scattering detection (ELSD) has proven to be a powerful analytical tool for developing unique chromatographic profi les to help insure product consistency and effi cacy, and to identify potential product adulterations. The ELSD is a semi-universal detector for LC that detects anything less volatile than the mobile phase to low nanogram levels. ELSD is fully gradient compatible, offering great fl exibility in separation techniques while maintaining a stable baseline independent of the spectral properties of the mobile phase.