Accelerated retention window

An accelerated retention window (ARW) starting from a certain proportion of organic (0A% acetonitrile) as the start of the gradient mobile phase composition was used to calculate preparative retention time on the basis of analytical retention time. The same procedure was used to adjust the retention times of all compounds to facilitate collection at the same predetermined retention time. This allowed set-up of a device for collecting any HPLC peaks that surpassed a certain threshold defined by UV or ELSD. 

Yan, B. et al. High-throughput purification of combinatorial libraries I A high-throughput purification system using an accelerated retention window approach. J. Comb. Chem. 2004, 6, 255-261. 

Table 16.11 shows the most recent classification scheme adapted by the American Society of Testing and Materials (ASTM) in 2001 (161). This classification is based on the elution of specific compounds within a retention time window defined by n-alkane carbon number. For example, for an accelerant to be classified in the light product range, the chromatogram must have the majority of the pattern occurring in the range from n-C4 to n-C9 with no major peak above... 

At the start of each MID retention time window, the magnet is automatically set to one mass (Da) below the lowest mass found in the MID descriptor. The magnet is parked, or locked and remains with this setting throughout the entire MID window. All analyser jumps to the calibration and target compound masses are done by fast electrical jumps of the acceleration voltage. 

A recent study published in the Chinese Journal of Instrumental Analysis, Fenxi Ceshi Xuebao, showed a detection limit of 500 ng of Sulfur Mustard (HD) by using accelerated solvent extraction-gas chromatography (ASE-GC) coupled with a flame photometric detector (EPD) in the sulfur mode, in soil. In this case, the study showed evidence that ASE results in better recoveries and sensitivity than liquid solid extraction (LSE) [50]. In 1996, a paper was published on a method for the analysis of Lewisite through derivatization of the compound before introduction into a gas chromatograph. In order to simplify the derivatization process, a tube packed with absorbent was used for collection of airborne vapors. If a positive response occurs when screening analytes using a GC coupled with an FPD, then the same sample can be analysed using a GC equipped with an AED for confirmation based on the elemental response to arsenic (in the case of Lewisite) and sulfur (in the case of Sulfur Mustard) within the appropriate GC retention time window [54]. 

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