A method for the quantification of sterols for a rapid screening of Smith-Lemli-Opitz Syndrome by Atmospheric Pressure Thermal Desorption Chemical Ionization -Mass Spectrometry (APTDCI -MS)

An atmospheric pressure thermal desorption chemical ionization MS/MS method to quantify cholesterol and 7- and 8-dehydrocholesterols directly in dried blood/plasma spots, is reported. Cholesterol levels from dried plasma spots of 23 unaffected subjects and 9 Smith-Lemli-Opitz patients by APTDCI-MS/MS method and by enzymatic method were correlated (y=0.9166x + 0.3811; r= 0.8831) as well as dehydrocholesterol levels obtained by APTDCI-MS/MS method and by GC-FID method (y=0.8214x + 0.7388; r= 0.8288).