In the pursuit of a system with a prenucleation cluster which would likely exhibit less CSA than molecular ATP, we set out to arrest calcium phosphate prenucleation clusters. 32 mM and 0.6487 mM phosphate and calcium respectively (other salts found in Supporting Information Materials). These spectra were chemical shift corrected to a phosphoric acid coaxial insert sample. An aliquot was taken at 3 hours after addition of calcium for DNP juice preparation and subsequently vitrified, found in part B. When left to react over a time period of 24 hours, the peak continues to shift left and sharpen, likely forming HAp. In B), the 1 H to 31 P CP 1D spectra of vitrified mSBF (referenced to phosphoric acid) in 60 % volume glycerol with a 1:9 total solution volume dilution factor, resulting in final concentrations of 0.147 mM phosphate and 0.072 mM calcium (complete preparation in Supporting Information Materials). The 31 P T 1 relaxation exceeded 100 s. The three blue regions are analyzed in part C. (C) Spin counting of vitrified mSBF sample with multi-cosine function curve fitting methodology (conventional SC analysis found in Figure ) using a mixture of frequencies 0 through 6 for both even and odd MQ-SC data sets (Supporting Information Section VI). For each even or odd experiment, the corresponding extracted MQCOs not filled in represent the opposite integer noise. Even and odd SC experiments were taken with a relaxation of 5 s and optimal excitation time of 4.8 ms at 10 kHz MAS. The right chemical shift environment suffered from low signal for even and odd SC, even at 256 and 512 scans respectively.