TY - JOUR
T1 - Development of a new measurement method for serum calcium with chlorophosphonazo-III
AU - Hokazono, Eisaku
AU - Osawa, Susumu
AU - Nakano, Tomota
AU - Kawamoto, Yukari
AU - Oguchi, Yuji
AU - Hotta, Taeko
AU - Kayamori, Yuzo
AU - Kang, Dongchon
AU - Cho, Yuichiro
AU - Shiba, Kiyoko
AU - Sato, Kenji
PY - 2009/7
Y1 - 2009/7
N2 - Background: Although serum calcium has been measured using the o-cresolphthalein complexone (oCPC) method in the clinical laboratory, this method still has some problems regarding linearity and reagent stability. We developed a new measurement procedure using chlorophosphonazo-III (CPZ-III: 2,7-bis (4-chloro-2-phosphonophenylazo) -1,8- dihydroxy-3, 6- naphthalenedisulphonic acid, disodium salt) as a chelator with an acid medium for serum calcium measurement. The present method showed better linearity and reagent stability compared with the oCPC method. Methods: Characteristics were studied in optimized conditions measuring wavelength by absorption spectra analysis, and interference of protein and metals with Mg2+, Fe 2+, Cu2+ and Zn2+. The method was applied to an automated analyser (7170; Hitachi High Technologies Corp). The measurement performance was evaluated for accuracy, precision, recovery rate, linearity and reagent stability with a comparison study against atomic absorption spectrophotometry (AAS). Results: The within-run and between-run variations (coefficient of variation [CV]) were 0.92-1.01% and 0.75-1.43%, respectively. The linearity was 0-7.0 mmol/L. The comparison study obtained y = 1.002x (AAS) - 0.10, Sy/x = 0.18 mmol/L, n = 50. Reagent stability was at least 20 d at 48C without daily calibration. Conclusion: The new calcium measurement method in serum was demonstrated to have reliable and acceptable performances as a routine test in clinical laboratory.
AB - Background: Although serum calcium has been measured using the o-cresolphthalein complexone (oCPC) method in the clinical laboratory, this method still has some problems regarding linearity and reagent stability. We developed a new measurement procedure using chlorophosphonazo-III (CPZ-III: 2,7-bis (4-chloro-2-phosphonophenylazo) -1,8- dihydroxy-3, 6- naphthalenedisulphonic acid, disodium salt) as a chelator with an acid medium for serum calcium measurement. The present method showed better linearity and reagent stability compared with the oCPC method. Methods: Characteristics were studied in optimized conditions measuring wavelength by absorption spectra analysis, and interference of protein and metals with Mg2+, Fe 2+, Cu2+ and Zn2+. The method was applied to an automated analyser (7170; Hitachi High Technologies Corp). The measurement performance was evaluated for accuracy, precision, recovery rate, linearity and reagent stability with a comparison study against atomic absorption spectrophotometry (AAS). Results: The within-run and between-run variations (coefficient of variation [CV]) were 0.92-1.01% and 0.75-1.43%, respectively. The linearity was 0-7.0 mmol/L. The comparison study obtained y = 1.002x (AAS) - 0.10, Sy/x = 0.18 mmol/L, n = 50. Reagent stability was at least 20 d at 48C without daily calibration. Conclusion: The new calcium measurement method in serum was demonstrated to have reliable and acceptable performances as a routine test in clinical laboratory.
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U2 - 10.1258/acb.2009.008099
DO - 10.1258/acb.2009.008099
M3 - Article
C2 - 19454535
AN - SCOPUS:67650823016
SN - 0004-5632
VL - 46
SP - 296
EP - 301
JO - Annals of Clinical Biochemistry
JF - Annals of Clinical Biochemistry
IS - 4
ER -