1.1 ,This test method describes the spectrophotometric determination of total aldehyde content in the range of 0.5 to 50 mg/kg (as acetaldehyde) or 0.3 to 35 mg/kg (as formaldehyde) in mono-, di-, and triethylene glycol (MEG, DEG and TEG). Alkoxyalcohols (hemiacetals), if present, are co-determined, whereas dialkoxyalkanes (acetals), if present, are not. The results provide a measure of the purity of the sample with respect to total aldehyde content.