.The royal copy of Łaski's Statute is part of the UNESCO Memory of the World national list. The use of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and high-performance liquid chromatography with ultraviolet–visible and electrospray ionization tandem mass spectrometry (HPLC-UV-Vis-ESI MS/MS) allowed for identification of dyes and mordants of black, white, and red silk threads.

This research project is dedicated to examinations of the chemical composition of seal cords of Łaski's Statute (1506), a significant document from the Polish-Lithuanian Commonwealth listed in the UNESCO Memory of the World national register. The cords, along with cords from four other royal documents of the same period, show considerable deterioration due to age and material components. The analysis employs laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (HPLC-UV-Vis-ESI MS/MS) to examine the inorganic mordants and organic dyes. The results reveal ellagitannin dyes in black cords, and madder and lac dye markers in one red cord. Some soluble redwoods (likely pernambuco, known also as brazilwood) are detected in the others, either on their own or as mixed with weld. The preservation state varies among cords, correlating with the mordants; iron predominates in the black and red threads of Łaski's Statute, contributing to their degradation, whereas the white cord exhibits higher sulfur content. In situ sampling using papers soaked with bathophenanthroline (Bphen) allows detection of major elements in the fibers. These findings are vital for guiding future conservation practices and mitigating risks in cleaning and restoring these delicate materials.