2-(8'-羟基喹啉-5'-磺酸-7'-偶氮)-变色酸测定血清镁

Determination of magnesium in serum by UV-spectrophotometry with 2-(8′-quinolinol-5′-sulfo-7′-Azo) chromotropic acid

目的建立简便、灵敏、试剂稳定性好的２－（８′－羟基喹啉－５′－磺酸－７′－偶氮）－变色酸（８Ｑ５ＳＡＣ）血清镁测定法。方法用国内合成的８Ｑ５ＳＡＣ作显色剂，ＥＧＴＡ掩蔽钙，在甘氨酸－ＮａＯＨ缓冲体系中以分光光度法测定血清镁。结果该法线性０～３ｍｍｏｌ／Ｌ，平均回收率９８．１％，变异系数１．９２％～２．９８％。与Ｃａｌｍａｇｉｔｅ法对照，ｒ＝０．９９６，Ｐ＞０．２；与ＭＴＢ法对照，ｒ＝０．９８３，Ｐ＞０．２；测试灵敏度分别是上述方法的２．５倍和４．３倍。结论该法简便、灵敏、试剂稳定性明显优于ＭＴＢ法和Ｃａｌ－ｍａｇｉｔｅ法，适于血清镁的常规手工分析和自动分析。

Objective To establish a simple sensitive and stable method for determination of magnesium in serum by UV spectrophotometry with 2 (8′ quinolinol 5′ sulfo 7′ azo) chromotropic acid (8Q5SAC). Methods 8Q5SAC was used as a coloring reagent and EGTA as a reagent covering calcium in the glycine NaOH buffer system to determine magnesium by spectrophotometry. The systematic studies of reaction conditions and properties of the method were made. Results The linearity was 0～3 mmol/L. The average rate of recovery was 98.1%, CV 1.92%～2.98%. Compared with Calmagite, it was shown that r =0.996, P >0.2, and with MTB, r =0.983, P >0.2. The method was 2.5 times the sensibility of Calmagite and 4.3 times the sensibility of MTB. Conclusions The sensibility of the method and the stability of the reagent are better than those in MTB′s and Calmagite′s. The method is suitable for the routine manual or automatic analysis of magnesium in serum.