An improved method for the simultaneous analysis of norepinephrine, epinephrine and dopamine at the picogram level by mass fragmentography
1977 Volume 53 Issue 6 Pages 785-796
Details
1977 Volume 53 Issue 6 Pages 785-796
Gas chromatography-mass spectrometry makes possible the simultaneous measurement of norepinephrine (NE), epinephrine (E) and dopamine (DA) at the picogram level. The equipment used was the Shimadzu LKB 9000 GC-MS (MID-PM). The TFA derivatives of the compounds were analysed by the GC-MS system equipped with a 3ft × 3mm column packed with 1.5% OV-1 and the temperature was programed from 135° to 260° at 10°C/min increments. The mass spectrum showed molecular ions at m/e 552,566 and 440 which corresponds to the TFA derivatives of NE, E and DA respectively. The base peaks of NE, E and DA were m/e 109,140 and 328 respectively. The peaks at m/e 126 (NE and DA) and 140 (E) were applied to avail themselves of simultaneous multiple-ion analyses by mass fragmentography.
As little as 4pg of the compounds injected into the column could be measured with good reproducibility, and the linearity of the response was maintained up to 120pg. The sensitivity was of the order of ng or pg which enables quantitation with 1ml of human serum and urine sample. The procedures were simpler and less time consuming than previously reported methods.
Recovery rates of NE, E and DA from serum were 2 5.7%, 13.7% and 76.1%, whereas those from urine were 100%, 89.6% and 100% respectively.
The specificity of this method surpasses and cannot be compared to any other existing quantitative methods.
