OPTIMIZATION AND VALIDATION OF AN ANALYTICAL METHOD FOR TRANEXAMIC ACID IN WHITENING CREAMS BY RP-HPLC WITH PRECOLUMN DERIVATIZATION

Objective: An efficient and selective analytical method with precolumn derivatization using reverse-phase high-performance liquid chromatography(RP-HPLC) was developed for the analysis of tranexamic acid in whitening creams.Methods: Derivatization was performed using 1% ninhydrin solution in methanol as a derivation agent to form a colored Ruhemann’s purple product.The analytical conditions included the use of a C18 column as the stationary phase and a methanol: acetate (20 mM) buffer at pH 4 (75:25) as themobile phase, with a flow rate of 0.8 mL/min and UV–visible detection at a wavelength of 570 nm.Results: The average retention time of the tranexamic acid derivative was 5.413 min. The results of the calibration curves were linear, with acorrelation coefficient (r) of 0.9993 at a concentration ranging from 8 to 48 μg/mL. The recovery was between 99.26% and 101.77%. The limits ofdetection and quantification were 1.87 μg/mL and 6.25 μg/mL, respectively.Conclusion: The analytical method developed in this study met the validation requirements and included a simple and efficient derivatization methodapplicable for the selective analysis of tranexamic acid in whitening creams.

Structural and Spectroscopic Properties of Metal Complexes with Ruhemann’s Purple Compounds Calculated Using Density Functional Theory

Structural and spectroscopic properties of Ruhemann’s purple (RP) and its transition metal coordination complexes were calculated using theoretical chemistry techniques. The obtained information described RP and its coordination complexes with the transition metal ions [Cr(II), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)]. The procedures involved calculations of what are called density functional theory (DFT) and time-dependent DFT (TD-DFT). These methods optimized what is called, in the codes of theoretical chemistry, the hybrid density B3LYP function employing the 6‐311++G(d,p) and LANL2DZ basis sets. The RP geometries, bond lengths, angles, quantum chemical parameters, and excitation spectra indicate that the RP is well able to coordinate with a transition element ion. Then the correlation of these theoretical results with experimental observations provides a detailed description of the structural and spectroscopic properties of RP compounds. The inclusion of solvent effects causes a blue shift in all theoretical excitation spectra. In summary, this work leads to an understanding of the characteristics of transition metal complexes with Ruhemann’s purple. These materials can be applied in forensic chemistry as reagents in developing latent fingerprints.

Development of Eco-Friendly Fingerprint Visualization using Herb

This study was aimed to develop an environmental-friendly fingerprint visualization using turmeric herb. The turmeric powder size was in the range of 60-200 mesh. The dusting method was done by applying turmeric powder to glass surface, aluminum foil, transparent plastic, plastic cups and compact disk (CD) surfaces that have sebum content from fingerprint samples. This study was also compared with the small particle reagent (SPR) of ninhydrin. The SPR method was done by spraying ninhydrin solution on A4 white paper and doorslag paper. The results of this study indicated that form of fingerprint obtained has the following pattern: radial loop (16.6 %), ulnar loop (63.3 %), tented arch (1.6 %), twinted loop (1.6 %) and plain whorl (16.6 %). The results showed that the turmeric powder dusting method gave a low contrast with yellow colour while ninhydrin SPR provides high contrast with Ruhemann’s purple.