An evaluation of a colorimetric kit method for the determination of inorganic phosphate (Pierce Phosphorus Auto/Stat Kit) is described. The within-batch and between-batch precisions were shown to fulfil current criteria, and recovery experiments, linearity studies, analyses of quality control materials, and studies of possible interfering substances evidenced good accuracy. Comparison of the results obtained on samples from patients with those obtained by the vanadate/molybdate continuous-flow method showed that the test method had a comparative positive bias. The use of a calibration reference serum as standard is recommended. The kit method is technically simple, requiring no protein precipitation, and analyses can be performed rapidly.
References
1.
BarnettR. N. (1968). Medical significance of laboratory results. American Journal of Clinical Pathology, 50, 671–676.
2.
BarnettR. N.YoudenW. J. (1970). A revised scheme for the comparison of quantitative methods. American Journal of Clinical Pathology, 54, 454–462.
3.
BroughtonP. M. G.GowenlockA. H.McCormackJ. J.NeillD. W. (1974). A revised scheme for the evaluation of automatic instruments for use in clinical chemistry. Annals of Clinical Biochemistry, 11, 207–218.
4.
ButtnerJ.BorthR.BoutwellJ. H.BroughtonP. M. G.BowyerR. C. (1976). Provisional recommendation on quality control in clinical chemistry. Part 2. Assessment of analytical methods for routine use. Clinica Chimica Acta, 69, F1–F17.
5.
DaviesJ. L.AndrewsG. S.MillerR.OwenH. G. (1973). Comparison of the stannous chloride and vanadate methods for estimation of serum inorganic phosphorus by use of the SMA 12/60. Clinical Chemistry, 19, 411–414.
6.
HenryR. J. (1964). Clinical Chemistry: Principles and Technics, pp. 411–416. Harper and Row, New York.
7.
KrynskiI. A.LoganJ. E. (1968). Observations on diagnostic kits for the determination of total cholesterol. Clinical Biochemistry, 2, 105–114.
8.
LoganJ. E. (1972). Evaluation of commercial kits. CRC Critical Reviews in Clinical Laboratory Sciences, 3, 271–289.
9.
TonksD. B. (1963). A study of the accuracy and precision of clinical chemistry determinations in 170 Canadian laboratories. Clinical Chemistry, 9, 217–233.
10.
WestgardJ. O.HuntM. R. (1973). Use and interpretation of common statistical tests in method-comparison studies. Clinical Chemistry, 19, 49–57.
