Nondestructive Differentiation of Polyester Single White Fibers Using Synchrotron Radiation Microbeam X-ray Fluorescence Spectrometry with Vertical Focusing*

In this study, the nondestructive differentiation of individual white polyester clothing fibers was accomplished via synchrotron radiation microbeam X-ray fluorescence (SR-mu-XRF) analysis. SR-mu-XRF with vertical focusing is a useful nondestructive method for the analysis of a single polyester clothing fiber. Kirkpatrick-Baez (KB) mirror was used to vertically focus 20 keV X-rays for the analysis of 22 individual white polyester fibers taken from clothing commonly sold in Japan. SR-mu-XRF with a vertical focused 2 mu m (V) x 300 mu m (H) beam was approximately 12.8 times more sensitive than SR-XRF with an unfocused 300 mu m (V) x 300 mu m (H) beam for the detection of elements in single fibers. The minimum detection limits (MDLs) of the SR-mu-XRF method were 8.15 ppm for Cl and 0.06 ppm for Br. In addition to Ti in TiO(2)delustering agents, Zr and Nb impurities in the delustering agents were detected in individual fibers. Sb from a polymerization catalyst and Co from a transesterification catalyst were also detected in individual fibers. Comparing the TiK beta/SbL(alpha,beta)and ZrK alpha/NbK alpha X-ray intensity ratios was a useful way to distinguish individual clothing fibers, and 98% of the fibers were differentiated when additional trace elements were used as discrimination indicators.