[A new method of measuring serotonin in plasma and cerebrospinal fluid]

A new rapid method for the microdetermination of serotonin (5-hydroxytryptamine) in plasma and cerebrospinal fluid is described. A recovery coefficient of 98% was obtained in the present method, with the use of [3H]-hydroxytryptamine creatinine sulphate as an internal standard, compared with recovery coefficients of 31% and 66% for the two existing methods generally used for serotonin determination. This method involves a one-step sample deproteinization by perchloric acid, resulting in a high stability of serotonin.