[Determination of antibiotics residues in the raw fresh milk of farms in the Miyun County of Beijing with Mg2+ -sensitized metacycline fluorescence microscopic imaging technique].
Mg(2+) -sensitized metacycline fluorescence microscopic imaging technique was applied to detect the raw fresh milk of four cows breeding farms in the Miyun County of Beijing based on the capillary effect of solvent on solid supports. In the presence of NH3-NH4 Cl buffer solution (pH 9.99) and PVA-124, Mg2+ and metacycline can form a strong fluorescence complex of 1 : 1, and Mg(2+) -metacycline complex can form an SOR on the hydrophobic supports with the diameter of 0.93 mm and its ring belt width of 26.2 microm. By measuring the fluorescence intensity of the ring, the quantitative analysis of metacycline was achieved with the detection limit (3sigma) of 8.8 x 10(-14) mol x ring(-1) (1.8 x 10(-7) mol x L(-1)) and linear range of 2.2 x 10(-13) -3.6 x 10(-12) mol x ring(-1) (4.4 x 10(-7) -7.2 x 10(-6) mol x L(-1)) when 0.50 microL droplet was spotted. This method has been satisfactorily applied to the determination of metacycline in the raw fresh milk samples with the recovery of 93.8%-108% and RSD less than 4.3%.
Liu
Ying
Y
College of Life and Environmental Science, Minzu University of China, Beijing 100081, China. liuying430@yahoo.com.cn
Yang
Le
L
D000818:Animals; D000900:Anti-Bacterial Agents; D002021:Buffers; D004350:Drug Residues / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis*; D057230:Limit of Detection; D008690:Methacycline / Q000032:analysis*; D008856:Microscopy, Fluorescence; D008892:Milk / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
D000900:Anti-Bacterial Agents; D002021:Buffers; D008690:Methacycline