Next Generation Peak Fitting for Separations

Separation scientists frequently encounter critical pairs that are difficult to separate in a complex mixture. To save time and expensive solvents, an effective alternative to conventional screening protocols or mathematical peak width reduction is called iterative curve fitting. This method does not sharpen the peaks to enhance the chromatographic resolution, but extracts the original shape from overlapping peaks in a complex separation, as if an isolated compound were injected. The generalized family of Haarhoff-van der Linde of peak functions accounts for most chromatographic peak shapes under analytical, isocratic or gradient elution, and mass-overloaded conditions. Four illustrative examples are discussed: i) subsecond separation of five compounds; ii) area extraction from 30 partially resolved peaks separated in under a minute; (iii) iterative curve fitting and baseline correction for a nicotine containing E-liquid; and (iv) advantages of fitting an overloaded peak shape for preparative separations. The large F-statistic, and R2 near to 1.0 in all cases, shows excellent modeling of the data’s variance.