HPLC‐MS of anthraquinoids, flavonoids, and their degradation products in analysis of natural dyes in archeological objects

Abstract

LC with MS detection was optimized for sensitive and selective analysis of main classes of natural dyes used in ancient times for dyeing textiles -- red anthraquinoids, yellow flavonoids, and known degradation products of flavonols -- hydroxybenzoic acids. Fragmentation patterns of both negative and positive molecular ions for the above mentioned compounds were investigated. Three acquisition modes of MS analysis: scanning, SIM, and multiple reaction monitoring (MRM) in both positive and negative ion modes were optimized and compared with each other and with the UV-Vis diode-array detection. Even though in the applied chromatographic system formic acid was used in the mobile phase, SIM in the negative ion mode was the most selective and sensitive detection for all the investigated compounds when both mixtures of standards and analysis of extracts from archeological samples were concerned, with one exception -- alizarin, for which MS detection in positive ion mode was more sensitive. Detection limits obtained with MS detection for all investigated compounds except quinizarin were lower than the ones obtained with the diode-array UV-Vis detection, making MS detection the most suitable tool for the analysis of natural dyes and their degradation products in extracts from archeological samples.

Capillary electrophoretic determination of main components of natural dyes with MS detection

“…Observed fragmentation of anthraquinoids was comparable to the one observed in HPLC-MS analysis with triple quadrupole instrument [30] and preceded mainly by the loss of CO, H 2 O and CO 2 . For emodin, the only anthraquinoid that has a methyl group in C6 position, loss of CH 3 (mass 15) radical in negative ion mode was also observed as mentioned before.…”

“…Fragmentation patterns for flavonoids were comparable to those observed for negative ESI mode in the triple quadrupole instrument and involved cleavage of 1/2 and 1/3 bonds and losses of small neutral molecules [30]. Interesting fragmentation pattern containing loss of CH 3 radical in case of rhamnetin was also observed.…”

Identification of anthraquinone dye colourants in red fibres from an Ohio Hopewell mound site by direct analysis in real time mass spectrometry

“…Many different analytical methodologies have been utilised for the identification of dyes in cultural heritage materials (Degano et al 2009). High-performance liquid chromatography with diode array UV-visible spectroscopy (DAD) and/or electrospray mass spectrometry (ESI-MS) detection are the most widely applied methods (Karapanagiotis and Chryssoulakis 2005;Surowiec, Szostek and Trojanowicz 2007;Lech, Połeć-Pawlak and Jarosz 2009;Zhang and Laursen 2009;Mantzouris et al 2011;Wouters, Grzywacz and Claro 2011). To apply HPLC to textile analysis, the dyes must first be extracted from the fibres; significant work has been done to establish the most appropriate and mildest conditions for extraction (Zhang and Laursen 2005;Valianou, Karapanagiotis and Chryssoulakis 2009;Manhita et al 2011).…”

Some forensic methods of the painting colour analysis

“…Visoko efikasna tečna hromatografija (HPLC) je najčešće upotrebljavani metod u analizi prirodnih boja (Surowiec, I. et al, 2007). On omogućava razdvajanje i identifikaciju velikog broja molekula iz male zapremine uzorka.…”

“…25 Prema pisanju Plinija, paleta slikara u klasičnoj Grčkoj bila je ograničena na samo četiri boje: crnu, belu, crvenu i žutu. 26 On nabraja najslavnije slikare -Apela, Ehiona, Melantija i Nikomaha -koji su svoja besmrtna dela izveli koristeći melinum (ceruse) za belu, atičku zemlju za žutu, pontsku sinopu za crvenu i atramentum za crnu. 27 Ciceron (Cicero) je produžio listu slavnih slikara, navodeći i Polignota, Zeuksida i Timanta.…”