One-step sensing lead in surface waters with screen printed electrode

The paper described a method for one-step sensing lead in surface waters. A screen printed carbon electrode was coupled with a paper disk impregnated with buffer and reagents including an internal standard Zn(II) and plating solution Bi(III), when the sample was added on the surface of electrode, it could be applied to run a single-step assay for lead detection in surface waters. Mechanism of internal standardization was discussed and the calibration constant was deduced. Detection of trace lead (ppb level) in 10 μL sample was performed. Surface waters with spiked Pb(II) were tested, the linear range was to 100 ppb, and 5–50 ppb Pb(II) was determined, the results were consistent with that by ICP-AES.