Measurement of prostaglandin F2alpha in human cerebrospinal fluid by single ion monitoring.

An imporved method is described for measuring low levels of prostaglandin F2alpha in small volumes of cerebrospinal fluid. Single ion monitoring of the ion at m/e 423, derived from the methyl ester tri-TMS ether derivatives of prostaglandin F2alpha and the internal standard, w-trinor-16-cyclohexyl prostaglandin F2alpha, is employed. Injection of 2 pg of prostaglandin F2 alpha derivative gave a standard deviation of +/- 9%. The majority of patients had cerebrospinal fluid levels of up to 2 ng ml-1 of prostaglandin F2 alpha, whereas in certain neurological conditions with progressive disease, elevated levels were encountered, some of which were higher than 10 ng ml-1.