Influence of inhibition of citric acid and lemon juice to the growth of calcium hydrogen phosphate dihydrate urinary crystals

Calcium hydrogen phosphate dihydrate (CHPD) crystal is a well-known urinary crystal. Calcium phosphate is present in urinary calculi (stones) as either apatite or brushite. Crystals of calcium hydrogen phosphate dihydrate were grown by single diffusion gel growth technique in silica gels. The supernatant solution containing combinations of constituents, like only calcium chloride, calcium chloride + citric acid; calcium chloride + lemon juice; calcium chloride + lemon juice + artificial reference urine (ARU) and calcium chloride + lemon juice + natural urine, were used to study the growth and inhibition of CHPD crystals. The growth velocity measurements indicated maximum inhibition in case of calcium chloride + lemon juice + natural urine containing solution. SEM (scanning electron microscope) and FTIR (Fourier transform infrared) spectroscopy were used to study the crystals. The results are discussed in terms of citrate inhibition and inhibition due to natural urine.