Our initial development of nh-PHIP for biofluids centered on urine as a simpler matrix (Figure ), largely free from interfering lipids and proteins. While useful for certain diagnostic purposes, it is the biological waste material and represents the end-products of the whole metabolome. Blood, instead reflects the human health status much better, since it represents mostly endogenous metabolites and is widely used for diagnostic and metabolomics purposes. It contains a wide variety of analytes that coordinate with the nh-PHIP catalyst (Scheme 1) and is free of ammonia, the dominant catalyst poison in urine.