Analysis of anatoxin-a in aqueous samples by solid-phase microextraction coupled to high-performance liquid chromatography with fluorescence detection and on-fiber derivatization.
A simple method for analysis of anatoxin-a in aqueous samples was developed using solid-phase microextraction (SPME) and high-performance liquid chromatography (HPLC) with fluorescence detection. Anatoxin-a was derivatized to a fluorogenic agent on the surface of the SPME fiber. In the method an SPME fiber was immersed for 30 min in the aqueous sample. The fluorogenic derivatizing reagent (4-fluoro-7-nitro-2,1,3-benzoxadiazole, 1.0 mg/ml in methanol) was dropped or sprayed onto the fiber containing extracted analytes. The fiber was then heated for 10 min in an empty vial at 70 degrees C in a waterbath to promote derivatization. The derivatives formed on the fiber were desorbed in a SPME-HPLC interface. The interface was filled with methanol-1 mM hydrochloric acid (7:3, v/v) before inserting of the fiber into the interface. For desorption, the fiber was inserted in the interface for 5 min. For anatoxin-a in an aqueous sample, the calibration curve showed linearity in the range of 50-1500 ng/ml and the limit of detection of anatoxin-a was 20 ng/ml. No interferences were found, and the time for analysis was 55 min for one sample.
Department of Chemistry, University of Waterloo, Ontario, Canada.
Akira
A
Namera
Angelina
A
So
Janusz
J
Pawliszyn
D001427:Bacterial Toxins / Q000032:analysis*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D000458:Cyanobacteria / Q000737:chemistry; D000087522:Cyanobacteria Toxins; D008387:Marine Toxins / Q000032:analysis*; D052998:Microcystins; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014326:Tropanes; D014874:Water Pollutants, Chemical / Q000032:analysis*
D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D008387:Marine Toxins; D052998:Microcystins; D014326:Tropanes; D014874:Water Pollutants, Chemical; C509783:anatoxin a