Organically nanoporous silica gel based on carbon paste electrode for potentiometric detection of trace Cr(III).
A new ion-selective electrode (ISE) for the detection of trace chromium(III) was designed by using 2-acetylpyridine and nanoporous silica gel (APNSG)-functionalized carbon paste electrode (CPE). The presence of APNSG acted as not only a paste binder, but also a reactive material. With 7.5 wt% APNSG proportions, the developed electrode exhibited wide dynamic range of 1.0 x 10(-8) to 1.0 x 10(-3) M toward Cr(III) with a detection limit of 8.0 x 10(-9) M and a Nernstian slope of 19.8 +/- 0.2 mV decade(-1). The as-prepared electrode displayed rapid response (approximately 55 s), long-time stability, and high sensitivity. Moreover, the potentiometric responses could be carried out with wide pH range of 1.5-5.0. In addition, the content of Cr(III) in food samples, e.g. coffee and tea leaves, has been assayed by the developed electrode, atomic absorption spectrophotometer (AAS) and atomic emission spectrometer (ICP-AES), respectively, and consistent results were obtained. Importantly, the response mechanism of the proposed electrode was investigated by using AC impedance and UV-vis spectroscopy.
Zhou
Wei
W
Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
Chai
Yaqin
Y
Yuan
Ruo
R
Guo
Junxiang
J
Wu
Xia
X
D002244:Carbon / Q000737:chemistry*; D002857:Chromium / Q000032:analysis*; D003069:Coffee / Q000737:chemistry; D017097:Electric Impedance; D004566:Electrodes; D005782:Gels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D011199:Potentiometry / Q000379:methods*; D011725:Pyridines / Q000737:chemistry; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013662:Tea / Q000737:chemistry
D003069:Coffee; D005782:Gels; D007477:Ions; D011725:Pyridines; D013662:Tea; D002857:Chromium; C543930:2-acetylpyridine; D002244:Carbon; D012822:Silicon Dioxide