Two- and three-dimensional PCA scores plots showing clear distinctions between four sets of n=2 replicate samples of four separate urine samples (coded RK2, RK28, RK37 and RK41) analysed using ¹H NMR spectroscopy at an operating frequency of 400 MHz. The colour codes provided on the right-hand side abscissa axes also provide information on the dates that the samples were analysed, for example the RK2-1 and RK2-2 samples correspond to the same sample analysed in duplicate on two separate occasions. Duplicate samples were prepared for analysis on each occasion.