Online clean-up of volatile compounds in complex matrices for GC-MS quantification: testing with fragranced consumer products

摘要

The quantification of volatile compounds in cosmetic products or raw materials remains problematic because of the complexity of the matrices. Two approaches were investigated on the basis of a full vaporization of analytes from a sample deposited on a cylinder of polydimethylsiloxane (PDMS) foam: (1) an internal standardization using the same calibration curve for all samples, which gives rise to unexplained peak magnifications that biases the determinations, and (2) a standard addition protocol. The latter was tested for the analysis of suspected allergens and allowed the quantification of all compounds except farnesol and Lyral~R. A decision tree was proposed to ascertain peak identity and the validity of the regression curve. Using this strategy in the range of 50-100 mg/l, 91% of all individual results (except farnesol and Lyral~R) in all matrices fell within a tolerance interval of ±25%. In addition, the use of disposable PDMS cylinders allowed 400 injections without polluting the injector or the column.