Fig. 1 depicts plots of the peak areas of the organic acids versusthe derivatization time. As shown in the charts of the supplemen-tary Fig. 1 and in Table 3, reaction yield increases until 30 min anddeclines slightly thereafter for most of the derivatives. Only pimelicacid exhibited an increase in the signal after 30 min. In contrast, gly-colic, methylmalonic, and 3-hydroxy-propionic acid exhibited thestrongest decline in signal intensity. Based on these results, 30 minwas considered the optimum time for the derivatization reactionof the organic acids with BSTFA/TMCS. Results showed satisfactoryrepeatability with low RSD values ranging from 0.14% (adipic acid)to 9.22% (glycolic acid).