[Fluorescence microscopic study of environmental water sample by a self-ordered ring technique with microwave heating].
A self-ordered ring (SOR) technique with microwave heating is proposed for the environmental water samples based on the capillary flow of solvent on the solid surface of glass slide support. In the reaction medium of pH 4.58 HAc-NaAc containing poly (vinyl alcohol)-124, a SOR of berberine with the outer diameter of 1.1 mm and the ring belt width of 19.2 microm can be formed using microwave heating and its fluorescence was quenched by picric acid. The maximum fluorescence intensity (Imax) was found to be proportional to picric acid content. When a 0.1 microL droplet of berberine-picric acid mixture was spotted on the solid surface, picric acid in the range of 1.3-30.0 x 10(-7) mol x L(-1) can be detected, and the limit of detection can reach 1.3 x 10(-8) mol x L(-1). With the present method, the contents of picric acid in natural water samples and synthetic samples were satisfactorily determined with its recoveries of 96.3%-108.0% and RSD lower than 3.3%. The sensitivity enhanced 50 times than that by spot analysis, and 60 times than that in solution. Moreover, the interference from background was reduced greatly. The authors believe that the SOR technique will find wide practicability and superiority in both environment and biochemistry.
Liu
Ying
Y
College of Pharmacy, Southwest University, Chongqing 400715, China. ly@imnu.edu.cn
Huang
Cheng-Zhil
CZ
D057230:Limit of Detection; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods*; D008872:Microwaves; D014874:Water Pollutants, Chemical / Q000032:analysis*
D014874:Water Pollutants, Chemical