The DHA Quant-PAK has been designed for the convenient, precise quantification of DHA by GC- or LC-MS. It includes a 50 μg vial of DHA-d5 and a precisely weighed vial of unlabeled DHA, with the precise weight (2-4 mg) indicated on the vial. This unlabeled DHA can be used to quantify the DHA-d5 standard by constructing a standard curve of peak intensity ratios (deuterated versus unlabeled).