Direct analysis of curcumin in turmeric by DART-MS.

The new ion source technique, direct analysis in real time (DART) atmospheric pressure ionisation, allows high resolution mass measurements of gas, liquid and solid samples. As DART-MS produces [M + H](+) molecular ions of most compounds, relatively simple and clear mass spectra are obtained even of multi-component samples. In order to take advantage of the capacity of DART-MS for the real time analysis of individual compounds in natural raw materials, a pilot study was performed using the well-known antioxidant botanical drug, turmeric. To establish the analysis methods of curcumin and its derivatives from various types of samples with DART-MS and compare the efficiency of the method with traditional HPLC method. Different curcuminoids were successfully detected directly from the raw particles of Curcuma longa. When a turmeric extract was separated on a TLC plate, each band produced molecular ion peaks corresponding to curcumin, demethoxycurcumin and bisdemethoxycurcumin. Molecular ions of curcuminoids in turmeric-containing beverages and curry powder were also efficiently detected. In addition to high efficiency of qualitative analysis, the evaluation of its linearity showed that DART-MS can be applied for semi-quantitative determinations of curcumin over a large range (5-100 microg/mL). A simple chemical profiling and semi-quantitative method for natural products using DART-MS might be applied to diverse field related quality control of medicinal plants or food ingredients.