Derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) followed by GC analysis provides a fast and reliable way to quantify aldehydes and ketones in ambient air. As with any analytical method, the availability of high quality analytical standards is important to ensure precision and accuracy of the analysis. However, until now the PFBHA derivatives of aldehydes and ketones have not been commercially available. To meet this need, Sigma-Aldrich now offers these derivatives as high purity standards for GC-MS.