Analysis of glass in product tampering investigations by inductively coupled plasma atomic emission spectrometry with a hydrofluoric acid resistant torch

Abstract

Early in 1986, the US Food and Drug Administration was faced with an epidemic of suspected product tampering complaints concerning glass found in jars of baby food. A fast, relatively inexpensive method was developed for characterising both the glass of the jars and the glass fragments found in the baby food. After dissolution in HF and HNO₃, the elemental composition of milligram to sub-milligram sized glass fragments was determined by inductively coupled plasma atomic emission spectrometry. Use of an HF-resistant nebuliser and torch allowed direct introduction of the sample solution. Comparison of the trace element content often allowed the discrimination of glass fragments when measurement of the refractive index proved inconclusive. Compilation of a preliminary database for the elemental composition of baby-food containers manufactured in the USA resulted from the investigation of numerous individual complaints.