茶碱与氧氟沙星合用时血药浓度的紫外测定方法

 目的建立一种能消除氧氟沙星干扰的茶碱血药浓度测定方法。方法用硫酸铵沉淀血清蛋白后以氯仿正己烷(7∶3)混和溶剂萃取，复用NaOH液(0.1 mol·L-1)抽提，并选择氧氟沙星的等吸收点275，299.5 nm为茶碱的测定波长。结果线性回收方程：ΔA=6.64×10-3+4.95×10-3C，r=0.9997，线性范围：5.0～40.0 mg·L-1。方法回收率100.3%，RSD为1.2%；萃取回收率87.7%，RSD为4.6%。结论本法不受氧氟沙星等多种抗菌素共存的干扰，可准确测定茶碱血药浓度。

A dual-wavelength spectrophotometry of serum theophylline with concomitant use of ofloxacin

OBJECTIVE　To develop a method for the determination of theophylline in serum with concomitant use of ofloxacin.METHODS　Theophylline was serum was extracted with chloroform-hexane(7∶3,v/v) after some ammonium sulfate was added.It was re-extracted with NaOH solution (0.1 mol*L-1)and detected with a UV spectrophotometer at 275 nm and 299.5 nm respeitively.RESULTS　The method was linear over the range of 5.0～40.0 mg*L-1(r=0.9997,n=7).The average recovery of methodology was 100.3%(RSD=1.2%),and the extraction recovery from serum was 87.7%(RSD=4.6%).CONCLUSION　This practical method for the determination of serum theophylline can eliminate the interference of ofloxacin and other antibiotics.