title: A direct gravimetric technique for measuring sebum excretion rate.
abstract: The standard gravimetric method for measuring sebum excretion rates involves ether extraction of the collected sebum. We have evaluated a more direct method in which the collecting papers were pre- and post-weighed in glass beakers under conditions of stable temperature and humidity. Weights were adjusted allowing for control weight gain or loss, due mainly to day to day changes in weight room humidity. The direct method compared favourably with the ether extraction method in determining: (1) sebum collected from 43 subjects (r = 0.991, P less than 0.001), (2) left versus right forehead comparisons in 19 subjects (direct method: r = 0.966, P less than 0.001; ether extraction method: (r = 0.963, P less than 0.001), and (3) recovery of sebum from 32 premeasured standards (r = 0.997, P less than 0.001). The findings demonstrate the accuracy of the direct gravimetric procedure which is also simpler, safer and less expensive than methods currently in use.
mesh_terms: D005546:Forehead; D006801:Humans; D006813:Humidity; D008722:Methods; D012015:Reference Standards; D012629:Sebum / Q000032:analysis / Q000378:metabolism*; D013046:Specific Gravity