The pool will be divided into 15 aliquots and individually spiked each of the following 14 compounds. One aliquot form the pool will remain un-spiked. Each spiked aliquot will then be further divided into three aliquots. One aliquot will remain spiked with the compound only, one aliquot will be further spiked with 5ng/mL of Cotinine and one aliquot will be further spiked with 15ng/mL Cotinine.