Comparative Study Between MALDI-TOF-MS and HPLC-DAD-TOF- MS Techniques in Identifying Dyes in A Heritage Caucasian Carpet

Variant techniques have been utilized in the identification of dyes in heritage textiles and carpets. Mass spectrometry is the most used one either in an invasive way by extraction of dyes from fibers or in a non-invasive way by direct analysis without extraction. The present work aims at presenting a pioneer comparative study between both techniques in identifying dyes in a heritage Caucasian carpet preserved in the Agricultural Museum in Egypt. The study used MALDI-TOF-MS as a non-invasive technique and HPLC-DAD-TOF-MS as an invasive one to clarify the points of strength and weakness in each method, and to recommend which one we may use, and in which object. The obtained results prioritized using MALDI-TOF-MS due to its easiness, fastness, cost-effectiveness, no chemicals or hazards, and almost no sampling. HPLC-DAD-TOF-MS proved that it is more accurate and universal and able to detect more components. MALDI-TOF-MS was able to efficiently identify madder and indigo/woad in almost all samples, so it is recommended in these cases. On the contrary, HPLC-DAD-TOF-MS is recommended in case of MALDI-TOF-MS failure, or in distinguishing between dyes, especially weld, fustic, and other dyes, which were efficiently characterized only by HPLC-DAD-TOF-MS.