固相萃取－高效液相色谱手性流动相添加剂法测定血浆中氧氟沙星对映体

目的：建立固相萃取-高效液相色谱法（high performance liquid chromatogoraphy，HPLC）拆分及测定血浆中氧氟沙星对映体的方法。方法：以L-异亮氨酸为配合剂，Cu2＋为配合离子，采用HPLC手性流动相添加剂法测定血中氧氟沙星对映体的含量。色谱柱为ODS—BP柱（250mm×4．6mm，5μm），内标物为环丙沙星，流动相为手性添加剂溶液（含1．31g／LL-异亮氨酸和0．80g／LCuSO。）-甲醇（81．5：18．5），激发波长为330nm，发射波长为504nm，流速为0．8mL／min。其中，应用C18固相萃取小柱萃取血浆中的氧氟沙星。结果：在经过优选的色谱条件下，对映体可以良好分离，分离度达到1．5以上；S-（-）-与R-（＋）-氧氟沙星的线性范围均为0．08～20μg／mL（r分别为0．9945和0．9947），最小检测限均为4ng／mL，平均萃取回收率分别为89．77％和88．07％，平均回收率分别为97．19％和98．39％，日内RSD分别为2．9％和3．0％，日间RSD为2．0％和2．2％。结论：该法血样处理简单，干扰小，灵敏度高，精密度好，可以作为对血浆中左、右旋氧氟沙星分别测定的方法。

Determination of Enantiomers of Ofloxacin in Serum by Solid-Phase Extraction and HPLC with Chiral Mobile Phase Additives

Objective:To set up a method to separate and determine the enantiomers of ofloxacin in serum by solid-phase extraction and high performance liquid chromatography.Methods:L-isoleucine as the additive and Cu2+ as the ligand ion were used to extract the ofloxacin in serum by solid phase extraction with C18 SPE column,then to separate and determine the enantiomers of ofloxacin in serum by HPLC with chiral mobile phase additive.The chromatography column used was a ODS-BP column(250 mm×4.6 mm,5μm).The mobile phase was made up of the chiral additive solution(including L-isoleucine(1.31g/L) and CuSO4(0.80 g/L)) and methanol(81.5∶ 18.5).The excitation and emission wavelengths were 330 nm and 504 nm,respectively.The flow rate was 0.8 mL/min.Results:Under the selected chromatography conditions,the enantiomers of ofloxacin coμLd could be separated and the resolution was higher than 1.5.The linear range of both S-(-)-and R-(+)-ofloxacin was 0.08～20 μg/mL(r values were 0.994 5 and 0.994 7 respectively);The minimal detection limits of them were 4 ng/ml;The mean extraction recoveries of them were 89.77% and 88.07%;The mean recoveries of them were 97.19 % and 98.39%;The daily RSDs were 2.9% and 3.0% respectively;And the between-day RSDs were 2.0% and 2.2%.Conclusion:The method is simple,sensitive and precise in the pretreatment of the bio-samples.It can be suggested to determine S-(-)-and R-(+)-ofloxacin in serum,respectively.