Identification of Contamination on Welding Wires Using Cross-Platform Techniques in SEM and Mass Spec
A batch of contaminated welding wire received from a vendor by a customer was causing problems in a manufacturing process. Visual comparison of the clean and contaminated wire did not show any obvious differences, but the contamination was readily observed on backscatter electron images obtained with the JEOL IT300 scanning electron microscope (Figure 1).
A JEOL AccuTOF™-DART® mass spectrometer equipped with a Biochromato IonRocket™ thermal desorption and pyrolysis attachment were used to determine the chemical composition of the wire contamination. The IonRocket includes an oven and disposable sample holders that permit controlled heating of samples from ambient temperature up to 600°C. The resulting thermal desorption profiles facilitate the identification of volatile compounds and outgassing. At higher temperatures, pyrolysis products permit the identification of materials such as polymers.