m/z-value m/z-value Ion type Retentiontime [min] Structure assignment
(exp.) (theo.)    
1. Peak 2. Peak
   
       
           
          PI(34:2)
833.56 833.52 [M-H] 31.26
835.54 835.53 31.81 PI(34:1)
[M-H]
         
857.54 857.52 31.07 PI(36:4)
[M-H]
         
859.55 859.55 31.09 PI(36:3)
[M-H]
         
861.56 861.55 31.15 PI(36:2)
[M-H]
         
883.55 883.53 30.99 PI(38:5)
[M-H]
         
885.59 885.55 30.97 PI(38:4)
[M-H]
         
899.57 899.52 31.05 PI(h38:5)
[M-H]
         
901.56 901.54 30.97 PI(h38:4)
[M-H]
         
909.59 909.55 30.99 PI(40:6)
[M-H]
         
917.56 917.61 30.95 PI(40:2)
[M-H]
         
571.31 571.29 34.66 LysoPI(16:0)
[M-H]
         
595.31 595.29 34.64 LysoPI(18:2)
[M-H]
         
597.33 597.30 34.50 LysoPI(18:1)
[M-H]
         
599.35 599.32 34.50 LysoPI(18:0)
[M-H]
         
619.33 619.29 34.39 LysoPI(20:4)
1095.65 1095.64 35.72 GM3(d18:1/12:0)
[M-H]
         
1123.72 1123.67 35.61 GM3(d18:1/14:0)
[M-H]
         
1137.70 1137.65 35.48 GM3(t18:1/14:1)
[M-H]
         
1149.73 1149.69 35.54 GM3(d18:1/16:1)
[M-H]
         
1151.74 1151.71 35.50 GM3(d18:1/16:0)
[M-H]
         
1165.74 1165.69 35.54 GM3(t18:1/16:1)
[M-H]
         
1167.75 1167.70 36.38 GM3(t18:1/16:0)
[M-H]
         
1177.75 1177.72 35.40 GM3(d18:1/18:1)
[M-H]
         
1179.78 1179.74 35.40 GM3(d18:1/18:0)
[M-H]
         
1193.78 1193.72 35.40 GM3(t18:1/18:1)
[M-H]
         
1205.77 1205.75 35.29 GM3(d18:1/20:1)
[M-H]
         
1207.79 1207.77 35.29 GM3(d18:1/20:0)
[M-H]
         
1219.77 1219.73 35.42 GM3(t18:1/20:2)
[M-H]
         
1221.79 1221.75 35.15 GM3(t18:1/20:1)
[M-H]
         
1233.84 1233.78 35.20 GM3(d18:1/22:1)
[M-H]
         
1235.83 1235.80 35.20 GM3(d18:1/22:0)
[M-H]
         
1247.82 1247.76 35.12 GM3(t18:1/22:2)
[M-H]
         
1249.83 1249.78 35.16 GM3(t18:1/22:1)
[M-H]
         
1257.82 1257.79 35.25 GM3(d18:1/24:3)
[M-H]
         
1259.83 1259.80 35.18 GM3(d18:1/24:2)
1261.85 1261.82 35.12 GM3(d18:1/24:1)
[M-H]
         
1263.86 1263.83 35.11 GM3(d18:1/24:0)
[M-H]
         
1275.82 1275.80 35.20 GM3(t18:1/24:2)
[M-H]
         
1277.85 1277.81 36.02 GM3(t18:1/24:1)
[M-H]
         
1279.88 1279.83 35.98 GM3(t18:1/24:0)
[M-H]
         
1291.83 1291.79 35.25 GM3(t18:1/h24:2)
[M-H]
         
1293.82 1293.81 35.08 GM3(t18:1/h24:1)
[M-H]
         
1295.86 1295.82 36.54 GM3(t18:1/h24:0)
[M-H]
         
1354.84 1354.79 38.17 GM2(d18:1/16:0)
[M-H]
         
1368.84 1368.76 38.06 GM2(t18:1/16:1)
[M-H]
         
1380.84 1380.80 38.09 GM2(d18:1/18:1)
[M-H]
         
1382.86 1382.82 38.11 GM2(d18:1/18:0)
[M-H]
         
1396.83 1396.81 [M-H] 38.06 GM2(t18:1/18:1)
Table 2: Acidic lipid species detected by (-) nano-HPLC/MS analysis of purified ganglioside fractions corresponding to 1.5 μl human serum of a control volunteer patient. Analyte species printed in bold were monitored within the complete set of investigated samples. Asterisks indicate a subset of ions that was not employed for data normalization since low signal intensity hampered their reproducible detection even within the control group.