Purifying fragrance compounds post synthesis is challenging. Fragrance chemicals are volatile molecules that have a smell or odor, and most fragrance molecules are limited to molecular weights below 300 Daltons. Typically distillation or flash purification are used where large quantities (gram scales) of reaction products are separated by the use of a column packed with normal or reverse-phase silica. However, in contrast to pharmaceutical and agrochemical applications, automated flash systems are not common in the fragrance industry. Many fragrance compounds have no chromophore, so UV detectors are of limited use. Furthermore, the high volatility of the fragrance molecules restricts the use of other detectors such as ELSD.