研制了甲氧苄啶分子印迹吸附萃取搅拌棒涂层,并应用于复杂样品中痕量甲氧苄啶和磺胺药物的分析。分子印迹涂层的厚度约为21.5μm,相对标准偏差为5.9%(n=10),涂层均匀、致密,具有良好的热稳定性和化学稳定性。分子印迹涂层的萃取容量是非印迹涂层萃取容量的1.7倍,分子印迹涂层对抗菌增效剂、磺胺药物、三嗪化合物和甲氨蝶呤都表现出良好的选择性吸附萃取能力。建立了分子印迹吸附萃取搅拌棒联用高效液相色谱的分析方法,成功应用于加标尿样和血浆中痕量甲氧苄啶的分析,线性范围为5~200μg/L,检出限为1.6μg/L,在尿样和血浆中的回收率范围分别为84.5%~91.7%和71.9%~85.1%,标准偏差分别为2.9%~4.4%和3.0%~7.3%。该方法还应用于加标牛奶中痕量磺胺药物的分析,线性范围为10~200μg/L,检出限在4.5~6.1μg/L之间,回收率为83.2%~110.2%,标准偏差为4.1%~8.0%.
Trimethoprim molecularly imprinted polymer (MIP) was prepared as the coating of stir bar sorptive extraction (SBSE) and applied to the trace analysis of trimethoprim and three sulfonamides in complex samples. The MIP-coating was about 21.5μm thickness with the relative standard deviations (RSD) of 5.9% (n= 10). It was homogeneous and dense with good thermal and chemical stability. The extraction capability of the MIP-coating was 1.7 times over that of the non-imprinted polymer (NIP) coat ing. The MIP-coating exhibited selective adsorption ability to sulfonamides, triazines and methotrexate besides antibacterial syner- gists. The methods for the determination of trimethoprim and three sulfonamides by MIP-coated stir bar sorptive extraction coupled with HPLC were developed. It was successfully applied to the trace trimethoprim analysis in spiked urine and plasma samples. The linear range was 5 to 200 μg/L and the detection limit was 1.6μg/L. The recoveries in urine and plasma samples were 84.5% to 91.7% with RSDs of 2.9% --4.4%, 71.9% to 85.1% with RSDs of 3.0% --7.3%, respectively. The trimethoprim MIP coated stir bar was also applied to the trace sulfonamides analysis in spiked milk sample. The linear range was 10--200 μg/L, the detection limit was within the range of 4.5--6.1 μg/L, and the recovery was 83.2% --110.2% with RSDs of 4.1% --8.0%.