Analytical Sciences

Abstract − Analytical Sciences, 28(2), 141 (2012).

Highly Sensitive Determination of Cadmium and Lead Using a Low-cost Electrochemical Flow-through Cell Based on a Carbon Paste Electrode
Wanida WONSAWAT,*1 Wijitar DUNGCHAI,*2 Shoji MOTOMIZU,*3 Suchada CHUANUWATANAKUL,*1,*4 and Orawon CHAILAPAKUL*1,*4
*1 Electrochemistry and Optical Spectroscopy Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand
*2 Department of Chemistry, Faculty of Science, King Mongkut’s University of Technology Thonburi, 91 Pracha-utid Road, Toongkru, Bangkok 10140, Thailand
*3 Department of Chemistry, Faculty of Science, Okayama University, 3-1-1 Tsushimanaka, Okayama 700-8530, Japan
*4 Center of Excellence for Petroleum, Petrochemicals and Advanced Materials, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand
A low-cost thin-layer electrochemical flow-through cell based on a carbon paste electrode (CPE), was constructed for the highly sensitive determination of cadmium(II) (Cd2+) and lead(II) (Pb2+) ions. The sensitivity of the proposed cell for Cd2+ and Pb2+ ion detection was improved by using the smallest channel height without the need for any complicated electrode modification. Under the optimum conditions, the detection limits of Cd2+ and Pb2+ ions (0.08 and 0.07 μg dm−3, respectively) were 13.8- and 11.4-fold lower than that of a commercial flow cell (1.1 and 0.8 μg dm−3, respectively). Moreover, the percentage recoveries of Cd2+ and Pb2+ for the in-house designed thin-layer flow cell were higher than those for the commercially available cell in all tested water samples, and within the acceptable range. The proposed flow cell is promising as an inexpensive and alternative one for the highly sensitive monitoring of heavy metal ions.