Sequential SERS determination of aspirin and vitamin C using in situ laser-induced photochemical silver substrate synthesis in a moving flow cell.
In this contribution, the utility of sequential injection analysis in combination with surface-enhanced Raman spectroscopy (SERS) as a detection technique was investigated for simultaneous determination of aspirin and vitamin C in their pharmaceutical dosage forms and in spiked urine samples. The silver substrate was synthesized in situ by laser-induced photochemical procedure. By focusing the laser on a flow cell at 1 ml/min of continuous flow of 0.5 mM silver nitrate and 5 mM sodium citrate mixture, an active silver spot on the inner wall of the flow cell was prepared in a few seconds. The whole setup is fully computer controlled using ATLAS software to combine the two techniques. The system allows sequential determination of aspirin concentrations ranging from 100 to 500 ng/ml and vitamin C concentrations between 10 and 110 ng/ml with good precision of relative standard deviations (RSDs) of 0.85 and 1.7 %, respectively. A comparison of these results with those of the reported procedures showed excellent results compared with t and F values, indicating good accuracy and precision. The detection limits were 32 and 3 ng/ml for aspirin and vitamin C, respectively.
Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/151, 1060, Vienna, Austria. marwazahry@aun.edu.eg.|Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526, Assiut, Egypt. marwazahry@aun.edu.eg.
Marwa R
MR
El-Zahry
Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526, Assiut, Egypt.
Ibrahim H
IH
Refaat
Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526, Assiut, Egypt.
Horria A
HA
Mohamed
Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/151, 1060, Vienna, Austria.
Bernhard
B
Lendl
D001205:Ascorbic Acid / Q000032:analysis*; D001241:Aspirin / Q000032:analysis*; D006801:Humans; D057230:Limit of Detection; D008855:Microscopy, Electron, Scanning; D010777:Photochemistry; D012834:Silver / Q000737:chemistry*
D012834:Silver; D001205:Ascorbic Acid; D001241:Aspirin
Aspirin; In situ silver photoreduction; SERS; Sequential injection analysis; Vitamin C