Retention time locking

Cook, J., M. Engel, P. Wylie, et al. 1999. Multiresidue screening of pesticides in foods using retention time locking, GC-AED, database search, and GC/MS identification. J. AOAC Int. 82 313-326. 

Kende, A., Z. Csizmazia, T. Rikker, et al. 2006. Combination of stir bar sorptive extraction—retention time locked gas chromatography-mass spectrometry and automated mass spectral deconvolution for pesticide identification in fruits and vegetables. Microchem. J. 84 63-69. 

Shifts in retention times are minimized by proper instrument maintenance, paecise control of instrumental conditions or by using approaches such as retention time locking in GC to account for variations in instrument performance (Etxebarria et al., 2009 Mortimers et al., 2011) and relative retention times in CE. Even with these apiproaches, some retention time shifting will occur and require more advanced alignment techniques for correction prior to chemometric analysis. 

Retention time locking procedure for comprehensive two-dimensional gas chromatography. Journal of Chromatography A, Vol.1218, No.21 (May, 2011), pp. 3159-3165 ISSN 0021-9673... 

Rasanen, I. Kontinen, I. Nokua, J. Ojanpera, I. Vuori, E. Precise gas chromatography with retention time locking in comprehensive toxicological screening for drugs in blood. J. Chromatogr. B, 20 3, 788, 243-250. 

Retention-time locking (RTL) is a unique feature available in some GC equipment which has revolutionized gas chromatography by reproducing retention times within hundredths of a minute from one instrument to another. This capability is possible thanks to highly reliable electronic pneumatic control (EPC), (pressure and flow control), good temperature control and high reproducibility of capillary columns. The result is ultimately retention time stability between any GC systems with EPC. 

Retention-time locking provides the immediate benefits of increased sample throughput, greater confidence in results, easier analysis for compliance, and lower costs of sample analysis. All you need is a GC equipped with the RTL software, EPC, and a GC ChemStation. With RTL, all peaks match and elution order is constant. Retention-time locking eliminates the need to update calibration tables, timed events tables, and integration events tables when a method is transferred, a new column is installed, or routine maintenance is performed. 

Recently the concept of retention time locking was introduced and this opens new perspectives in capillary GC for solute elucidation (see Section 11.10.2). 

Recent developments in capillary GC, i.e., electronic pneumatic control (EPC) of the carrier gas, improved oven temperature stability, and excellent reproducibility in column making have led to the concept of retention time locking (RTL) [77], [78]. With retention time locked data bases, absolute retention times instead of retention indices can be used to elucidate the structures of eluting solutes. Moreover, retention time locking can be u.sed in combination with different injectors and detectors. Exact scaling of capillary GC-FID, capillary GC-MS, and capillary GC-AED chromatograms is feasible. 

Figure 65. Capillary GC - AED chromatogram at the 837 nm emission line of a white wine extract recorded under RTL conditions Table 7. Results of retention time locked pesticide data base search...

Free downloads of software retention time locking, method translation Technical libraries of chromatograms searchable by solute or class of solutes Column cross-reference charts Application Notes... 

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