Characterization of high-purity chemicals for use as clinical laboratory standards.

Some practical approaches to the broad analytical definition of high-purity chemicals for use as clinical laboratory standards are highlighted. Techniques applied include precision gravimetry and titrimetry, differential scanning calorimetry, phase solubility analysis, emission spectrography, flame absorption photometry, polarography, cold-vapor atomic absorption photometry (for mercury), solution photometry, turbidimetry, thin-layer chromatography, as well as general tests, and the measurement of properties. The characterization of various standards is delineated, including standards for calcium, chloride, lithium, magnesium, phosphate, potassium, sodium, creatinine, dextrose, glycine, urea, and uric acid.