TY - JOUR
T1 - Increased speed of analysis in directly coupled gas chromatography-mass spectrometry systems
T2 - capillary columns at sub-atmospheric outlet pressures
AU - Cramers, C.A.M.G.
AU - Scherpenzeel, G.J.
AU - Leclercq, P.A.
PY - 1981
Y1 - 1981
N2 - A theoretical treatment of the optimum gas chromatographic conditions for open-tubular columns, operated at vacuum outlet pressures, is presented. Equations are given for the minimum plate height, the optimum linear gas velocity and the optimum inlet pressure. The maximum column efficiency was calculated to decrease by 12.5% at most, compared with atmospheric outlet conditions. The gain in speed of analysis obtained with vacuum outlet columns is dependent upon the nature of the carrier gas and increases strongly with lower (sub-atmospheric) optimum inlet pressures. The use of short and/or wide-bore columns can therefore be recommended.
Experimental results indicate the validity of the theory, although no loss in efficiency has been observed. The ultimate gas chromatography-mass spectrometry coupling device thus appears to be no device at all: the end of the column need only be inserted into the ion source of a mass spectrometer. In addition to the gain in speed of analysis, the many problems caused by wall effects and dead volumes in interface lines are avoided by this method. Moreover, the gas chromatographic peaks are narrower and thus higher, lowering detection limits
AB - A theoretical treatment of the optimum gas chromatographic conditions for open-tubular columns, operated at vacuum outlet pressures, is presented. Equations are given for the minimum plate height, the optimum linear gas velocity and the optimum inlet pressure. The maximum column efficiency was calculated to decrease by 12.5% at most, compared with atmospheric outlet conditions. The gain in speed of analysis obtained with vacuum outlet columns is dependent upon the nature of the carrier gas and increases strongly with lower (sub-atmospheric) optimum inlet pressures. The use of short and/or wide-bore columns can therefore be recommended.
Experimental results indicate the validity of the theory, although no loss in efficiency has been observed. The ultimate gas chromatography-mass spectrometry coupling device thus appears to be no device at all: the end of the column need only be inserted into the ion source of a mass spectrometer. In addition to the gain in speed of analysis, the many problems caused by wall effects and dead volumes in interface lines are avoided by this method. Moreover, the gas chromatographic peaks are narrower and thus higher, lowering detection limits
U2 - 10.1016/S0021-9673(00)80294-0
DO - 10.1016/S0021-9673(00)80294-0
M3 - Article
SN - 0021-9673
VL - 203
SP - 207
EP - 216
JO - Journal of Chromatography
JF - Journal of Chromatography
ER -