Identification of anthraquinone coloring matters in natural red dyes by electrospray mass spectrometry coupled to capillary electrophoresis

Abstract

Capillary electrophoresis with UV/visible diode-array detection (DAD) and electrospray mass spectrometric (ESI-MS) detection were used for the identification of anthraquinone color components of cochineal, lac-dye and madder, natural red dyestuffs often used by ancient painters. For the purpose of such analysis, ESI-MS was found to be a much more appropriate detection technique than DAD one owing to its higher sensitivity (detection limits in the range 0.1-0.5 micro g ml(-1)) and selectivity. The method developed made it possible to identify unequivocally carminic acid and laccaic acids A, B and E as coloring matters in the examined preparations of cochineal and lac-dye, respectively. In madder, European Rubia tinctorum, alizarin and purpurin were found. The method allows the rapid, direct and straightforward identification and quantification of components of natural products used in art and could be very helpful in restoration and conservation procedures.

Determination of pharmacologically active compounds in root extracts of Cassia alata L. by use of high performance liquid chromatography

“…Several analytical methods such as thin-layer chromatography [28], micellar electrokinetic capillary chromatography [29], capillary zone electrophoresis [30], capillary electrophoresis-mass spectrometry (CE-MS) [31], gas chromatography [32], and gas chromatography-mass spectrometry (GC-MS) [33] have been used for the determination of anthraquinones in various medicinal plants and natural products. In addition, analytical methods involving the use of HPLC [32][33][34][35][36] and liquid chromatographymass spectrometry (LC-MS) [37][38][39][40] have also been used for anthraquinone analysis in several natural products.…”

Simultaneous identification of natural dyes in the collection of drawings and maps from The Royal Chancellery Archives in Granada (Spain) by CE

“…Alizarin and purpurin are coloring agents and are found in the roots of R. tinctorum. Both of them are anthraquinones [11].…”

“…Various analytical techniques have been used for the identification of active coloring agents, e.g. spectrophotometry in the UV, Vis and IR regions [1][2][3], Raman spectrometry [4], fluorescence spectrometry [5], HPLC with UV-Vis diode array detection and fluorescence detection [6][7][8][9], HPLC with MS detection [10], CE with UV-Vis diode array detection and electrospray MS detection [11], pyrolysis-GC/MS and abrasive voltammetry [12][13][14] and voltammetry [15].…”

Micellar Electrokinetic Chromatography with Laser-Induced Fluorescence Detection for Separation of Red and Yellow Historical Dyes

“…The lack of specificity and the poor sensitivity of these approaches make them less than ideal for detecting small quantities of dye. A number of separation techniques have also been explored, and these include: thin layer chromatography (TLC) [16,17], high performance liquid chromatography (HPLC) [18,19], gas chromatography (GC) [20] and capillary electrophoresis (CE) [21][22][23][24][25][26]. High performance liquid chromatography is a common technique for separation of dyes and can be equipped with many different detection schemes, including UV-Vis and fluorescence detection, photodiode array (DAD) and mass spectrometry (MS).…”

“…Puchalska [21] used CE coupled with diode-array detection (DAD) and electrospray mass spectrometric (ESI-MS) detection to isolate and identify anthraquinone dyes. The separation of anthraquinones and flavonoids using CE with MS detection has been described by Surowiec [22].…”