An approach was proposed to develop enhanced fingerprint by means of high-performance liquid chromatography (HPLC) with photodiode array detection. The approach was applied to establish enhanced chromatographic fingerprints of various Artemisia selengensis Turcz which is a traditional Chinese medicine (TCM). In comparison with common fingerprint at a fixed wavelength, enhanced fingerprint compiled additional spectral data and was more informative. So it could be used to conduct the quality control of this TCM comprehensively. Thereafter, the chromatographic fingerprint data set was submitted for classification to a suite of chemometrics methods viz. similarity analysis (SA), hierarchical clustering analysis (HCA) and principal component analysis (PCA). Each method highly lighted different properties of the data matrix according to the fingerprints from different types of A. selengensis Turcz. It provided comprehensive information for matching and discrimination of the fingerprints, and appeared to be suited for quality assurance purposes for these similar types of sample.

Portulaca oleracea L. is a traditional edible and medicinal plant in China. Flavonoids are one of the main active ingredients of this plant. Five extraction technologies of flavonoids from P. oleracea L. were investigated and compared, including microwave-assisted extraction, ultrasonic extraction, reflux extraction, Soxhlet extraction, and marinated extraction. The results showed that microwave-assisted extraction was most suitable for the extraction of flavonoids from P. oleracea L. because of its high effect and short extraction time. The found optimum extraction conditions were that the ethanol concentration was 70% (v/v), solid–liquid ratio was 1:50, extracting temperature was 50 °C and irradiation time was 9 min. Quantification was performed by means of UV–Vis spectrophotometry with chromogenic system of NaNO2–Al (NO3)3–NaOH. Under the optimum conditions, the calibration curve for the analyte was linear with the correlation coefficients greater than 0.9999. The average recovery was 102.6%, and its RSD was 1.13%(n = 5). Eight types of P. oleracea L. according to different habits were investigated. The total content of flavonoids was 7.16, 7.10, 9.38, 6.82, 6.78, 11.36, 5.12, and 1.76 mg g−1, respectively.

Ultrasonically assisted extraction (UAE) followed by high performance liquid chromatography (HPLC) analysis method for the fast extraction and determination of rutin in Artemisia selengensis Turcz has been developed. Artemisia selengensis Turcz has been used as food and herbal medicine for thousands of years in China. Rutin is one of the main active ingredients of this plant. The extraction of rutin from Artemisia selengensis Turcz was investigated by UAE. Special emphasis has been given to optimize the extraction conditions which were those with 90:10 (v/v) methanol–ethanol as solvent, 30:1 liquid–solid ratio, and 40 min extraction time. In order to show the superiority of UAE, other extractions were investigated, including microwave-assisted extraction, reflux extraction, and marinated extraction. The results showed that UAE was most suitable for the extraction of rutin in Artemisia selengensis Turcz because of its high extraction efficiency. Reversed phase-HPLC with ultraviolet detection was employed for the analysis of rutin in Artemisia selengensis Turcz. Under the optimum conditions, the calibration curve for the analyte was linear in the range of 0.34–20.7 μg mL−1. The mean recovery of rutin was 100.77%, and its relative standard deviation was 0.37% (n = 5). Three kinds of Artemisia selengensis Turcz from different habitats were investigated. The total content of rutin was 9.90, 6.23, 5.56 mg g−1, respectively.

A fingerprinting approach was developed by means of gas chromatography–mass spectrometry (GC–MS) and IR spectroscopy for quality control of Portulaca oleracea L., a traditional Chinese food and medicine that has been used for thousands of years in China. Eleven P. oleracea L. samples obtained from different sources were used to establish the fingerprints, and the similarity evaluation and hierarchical cluster analysis were performed to evaluate the similarity and variation of these samples. The results showed that the 11 samples all have the similarity of greater than 0.84, indicating that the samples from different sources were consistent to great extent. The cluster analysis results of GC–MS and IR spectra were similar, and 11 samples from five provinces of China were divided into two main clusters: one was from North China and another from South China. It proved that both GC–MS fingerprint and IR spectral fingerprint could be used for the identification and differentiation of P. oleracea L. from different sources.

Andrographis paniculata Nees (A. paniculata) has been used as herbal medicine for thousands of years in China. In this work, a quick extraction method with microwave-assisted treatment was studied for a complete extraction of active compounds from A. paniculata. Furthermore, the proposed fingerprint method, enhanced fingerprint by HPLC-DAD, has the advantage of efficiency and accuracy. In comparison with common fingerprint at fixed wavelength, enhanced fingerprint compiled additional spectral data and was hence more informative. It could efficiently identify, distinguish and assess A. paniculata. So it could be used to conduct the quality control of this traditional Chinese medicine comprehensively.