سال انتشار: ۱۳۹۰
محل انتشار: اولین همایش ملی نانومواد و نانو تکنولوژی
تعداد صفحات: ۹
Kourosh Motevalli – applied chemistry department,technical & engineering faculty,Islamic azad university,south Tehran branch,Tehran,iran
Zahra Yaghoubi – address:industrial faculty,Islamic azad university,south Tehran branch,Tehran,iran
A practical and simple modified gold nanoparticle-disepersive liquid-liquid microextraction (MAuNps-DLLME) has been successfully applied as electrostatic affinity probes to the microextraction andpreconcentration of ofloxacin prior to spectrofluorimetry analysis. This technique is based on a ternary system of solvents, where appropriateamount of microextraction containing tetraalkylammonium bromide coated gold nanoparticles (AuNPs), and disperser solvents are directly injected intoan aqueous solution containing ofloxacin. A cloudy mixture is formed, and ofloxacin in the aqueous matrix is extracted into the fine droplets ofmicroextraction solvent containing AuNPs. The settled phase is collected and transferred into a micro-cell of fluorimeter for the determination ofofloxacin at excitation/emission wavelengths of 335/375 nm. The obtained results demonstrated that electrostatic attraction forces caused by AuNPswere much stronger than the hydrophobic attraction forces. Various factors influencing microextraction efficiency were studied and optimized. Underthe optimum conditions, the method provided a relatively broad linear dynamic range of 0.1 to 150 ng mL−۱, a detection limit of 0.02 ng mL−۱ anda relative standard deviation of 2.1%. Finally, the method was successfully applied to ofloxacin determination in actual pharmaceutical formulations and human urine sample.