Kendrick mass scale

The intention of the Kendrick mass scale is to provide data reduction in a way that homologs can be recognzed by their identical Kendrick mass defect (KMD). Due to the steadily increasing resolution and mass accuracy of modem instrumentation this issue is again gaining importance for complex mixture analysis by MS. The Kendrick mass scale is based on the definition = 14.0000 u [54]. The conversion factor from the lUPAC mass scale, mnjpAc, to the Kendrick mass scale, Kendrick. IS therefore 14.000000/14.015650 = 0.9988834  

we define the Kendrick mass defect, ffJdefectKendrick, as 

Example The lUPAC mass of [C3oH4903] is 457.3687 u. The Kendrick mass of this ion is calculated as 457.3687 u x 0.9988834 = 456.8580 u. From this it follows that WnomKendrick = 457 u. The KencMck mass defect of this ion is thus obtained as mdefectKendrick = 457 u - 456.8580 u = 0.1419 u. 

Example Crude oil / diesel fuel - In a Kendrick plot the conposition of complex systems can be conveniently displayed. Several thousand elemental compositions in the ultra-high resolution spectrum of petroleum crude oil [55] or diesel fuel [56] may be resolved. Such samples consist of numerous conpound classes and/or alkylation series with some 30 homologs each that can be visually identified (Fig. 3.27). The formula employed for the preceding example is marked in the plot by an arrow. 

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Kendrick, E. A mass scale based on CH = 14.0000 for high resolution mass spectrometry of organic compounds. Anal. Chem. 1963,35,2146-2154. 

Kendrick, E. Mass Scale Based on CH2 = 14.0000 for High-Resolution Mass Spectrometry of Organic Compounds. Anal. Chem. 1963, 35. 2146-2154. 

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