Tongkat Ali (Eurycoma longifolia) is one of the most popular tropical herbal plants as it is believed to enhance virility and sexual prowess. This study looked examined chromatographic fingerprint of Tongkat Ali roots and its products generated using online solid phase-extraction liquid chromatography (SPE-LC) combined with chemometric approaches. The aim was to determine its quality. Pressurised liquid extraction (PLE) technique was used prior to online SPE-LC using polystyrene divinyl benzene (PSDVB) and C18 columns. Seventeen Tongkat Ali roots and 10 products (capsules) were analysed. Chromatographic dataset was subjected to chemometric techniques, namely cluster analysis (CA), discriminant analysis (DA) and principal component analysis (PCA) using 37 selected peaks. The samples were grouped into three clusters based on their quality. The PCA resulted in 11 latent factors describing 90.8% of the whole variance. Pattern matching analysis showed no significant difference (p>0.05) between the roots and products within the same CA grouping. The findings showed the combination of chromatographic fingerprint and chemometric techniques provided comprehensive evaluation for efficient quality control of Tongkat Ali formulation.
Headspace solid phase microextraction (HS-SPME) was used to isolate volatile compounds (VOCs) from mangoes (Harumanis cv.). Among the four SPME fibres investigated, the mixed phase coating, 65 μm polydimethyl siloxane–divinylbenzene (DVB/PDMS) showed the highest efficiency in extracting VOCs as 26 compounds were detected with the total area of 9.6 x 109. The optimization of SPME factors was conducted in 2 stages using multivariate design. The first stage involved screening of the significant factors using the Plackett–Burman (P–B) design, followed by the optimization of the significant factors utilizing Central Composite Design (CCD). The experimental design for both P-B and CCD design was generated using Design-Expert version 6.0.4 (Stat Ease Software). Extraction time and temperature appeared to be the most significant factors in extracting VOCs in mangoes, with the optimum conditions prevailing at 55°C and 34 minutes respectively.