Fluorescent Microscopy Self-assembled Ring Antibiotic Content In The Samples Of Milk And Biochemical Detection Applications

Based on different methods for determination of antibiotics, the mechanism of the formation of self-ordered rings and SOR imaging fluorescent technique were introduced. The testing methods were set up for the determination of MTC, MC, ENX, CPX, SD and determined the concentration of antibiotics in milk, tablets, injection, urine, serum and synthesis samples.In the presence of NH3-NH4Cl buffer solution (pH 10.6) and PVA-124, the droplet of metacycline can form an SOR on the solid supports with the diameter of 1.84mm and its ring belt width of 59.6μm. The quantitative analysis of metacycline is achieved with the linear range of 3.39×10-13-2.03x10-12 mol·ring-1 (1.13×10-6-6.77×10-6 mol·L-1) and detection limit of 1.05×10-13 mol·ring-1 (3.50×10-7 mol·L-1) when 0.3μL droplet was spotted. Then the technique has been applied into the determination of metacycline in the tablets and residue in four different milk samples with the recoveries of 95.2%-106.2% and 94.7%-104.0%, respectively.In the presence of NH3-NH4Cl buffer solution (pH 9.99) and PVA-124, Mg2+and metacycline form a complex of 1:1 and the droplet of Mg2+-metacycline can form an SOR on the hydrophobic supports with the diameter of 0.93mm and its ring belt width of 26.2μm. By measuring the fluorescence intensity of the ring belt, the quantitative analysis of metacycline is achieved with the linear range of 1.30×10-13-2.1×10-12mol·ring-1 (4.40×10-7-7.20×10-6mol·L-1) and detection limit of 1.70×10-14mol·ring-1 (5.67×10-8mol·L-1) when 0.30μL droplet was spotted. Then this method has been applied into the determination of metacycline in the raw fresh milk samples with the recovery of 93.8%-107.8% and RSD less than 4.3%.In the presence of pH8.50 NH3-NH4Cl buffer solution, PVA-124 and microwave heating, the droplet of Ca2+sensitized minocycline could form an SOR on the hydrophobic support with the diameter of 1.7mm and ring belt width of 45.3μm after the solvent was evaporated. The linear range was 1.9×10-6-6.0×10-5 mol·L-1 and limit of detection was 1.9×10-7 mol·L-1 when 0.3μL droplet was spotted. Then the technique was applied into the detection of minocycline in the capsule and residue in the milk samples with the recoveries of 104.3%-105.0% and 96.0%-105.9%, respectively, RSD was less than 3.47%.In the presence of NH3-NH4Cl buffer solution (pH 9.70) and PVA-124, the droplet of Al3+-Enoxacin can form an SOR on the solid supports with the diameter of 1.63mm and its ring belt width of 50μm. The quantitative analysis of enoxacin is achieved with the linear range of 1.00×10-13-5.00×10-13mol·ring-1(5.00×10-7-2.50×10-6mol·L-1) and limit of detection 7.65×10-15mol·ring-1 (3.83×10-8mol·L-1) when 0.20μL droplet was spotted. Then the technique has been applied into the determination of enoxacin in the enoxacin gluconate injection and residue in four different milk samples with the recoveries of 96.9%-107.0% and 94.2%-102.5%, RSD less than 4.1% and 2.4%, respectively, and enoxacin average concentration in healthy volunteer's urine after oral administration and enoxacin average concentration in rabbit serum after oral administration were satisfactorily determined.The surfactant could be part of a higher level of complexes in the course of metal ions forming fluorescent complexes, thereby increasing the effectiveness of complex molecular absorption co efficiencies, resulting the increase of fluorescence. In the presence of surfactant CTMAB, NH3-NH4Cl buffer solution (pH9.70) and polyvinyl alcohol-124 (PVA-124). The droplet containing the chelate of ciprofloxacin-Al3+ could form an SOR on the solid support after solvent evaporation with the diameter of 2.76mm and its ring belt width of 43.5μm. The analytical parameters of ciprofloxacin were achieved with the linear range of 1.0×10-13-6.0×10-13 mol·ring-1 (5.0×10-7-3.0×10-6 mol·L-1) and detection limit of 1.0×10-14 mol·ring-1 (5.0×10-8 mol·L-1) when 0.2μL droplet was spotted. Then the technique had been satisfactorily applied to the determination of ciprofloxacin in different samples of milk, injection, tablets and rabbit serum samples.In the presence of HAc-NaAc buffer solution (pH3.12) and PVA-124, the droplet containing fluorescamine derivatized sulfadiazine can form an SOR on the solid support after solvent evaporation with the diameter of 1.86mm and its ring belt width of 54.9μm. The quantitative analysis of sulfadiazine is achieved with the linear range of 7.8×10-14-1.8×10-12 mol·ring-1 (3.9×10-7-9.0×10-6 mol·L-1) and detection limit of 7.8×10-15 mol·ring-1 (3.9×10-8 mol·L-1) when 0.2μL droplet was spotted. Then the technique has been satisfactorily applied to the determination of sulfadiazine in the tablets, synthetic sample and residue in six different milk samples with the recoveries of 91.0%-105.8%, respectively, RSD less than 4.4%.The proposed SOR technique showed great reliability and practicality by setting up several testing systems for antibiotics, offered a new way for the analysis and determination of antibiotic residues in milk and biochemical samples, and showed several advantages such as lower background interference, less consumption, simplicity, non-pollution to the environment, etc.