Heavy-Metal Analysis (Stripping)
Heavy-Metal Analysis by Stripping Voltammetry (ASV)
Stripping voltammetry detects lead, cadmium, zinc, copper and mercury at very low concentrations with far more compact equipment than AAS or ICP. This page covers the principle, the analysis workflow and the equipment.
- Pb · Cd · Zn · Cuin a single scan
- DPV · SWV · NPVCorrtest stripping techniques
- Compact setupno flame gases or plasma
- Official distributorof Corrtest in Indonesia
How stripping voltammetry works
The analysis has two stages. In the deposition stage the working electrode is held at a negative potential while the solution is stirred, so metal ions such as Pb²⁺ and Cd²⁺ are reduced and accumulate on the electrode. In the stripping stage the potential is swept positive with DPV or SWV; each metal re-oxidises at its characteristic potential, giving a current peak whose height is proportional to concentration.
Because the metal is pre-concentrated, the method is very sensitive. The Corrtest brochure shows stripping curves for a solution containing Pb²⁺, Cd²⁺ and Zn²⁺ and lists NPV, DPV, DNPV, SWV and ACV for quantitative trace-element analysis.
Analysis workflow
- Sample preparationFilter and acidify water; digest food or soil samples in acid first.
- Add supporting electrolyteTypically acetate buffer around pH 4.5; add Bi³⁺ ions for a bismuth-film electrode.
- Deposit while stirringHold a negative potential (e.g. −1.2 V vs Ag/AgCl) for 60–300 s with a magnetic stirrer.
- EquilibrationStop stirring for 10–15 s so the solution is quiet before the scan.
- Stripping scanSweep positive with SWV or DPV; record the peak height or area of each metal.
- Standard additionAdd standard two or three times and extrapolate the line to get the sample concentration.
- Clean the electrodeHold a positive potential briefly to remove remaining metal before the next run.
Stripping voltammetry versus AAS and ICP
| Aspect | Stripping voltammetry | AAS / ICP |
|---|---|---|
| Instrument cost | Potentiostat and glass cell | Much higher, plus gases and maintenance |
| Sensitivity | Very high thanks to pre-concentration | High (GF-AAS, ICP-MS very high) |
| Speciation | Can distinguish labile/bound forms | Usually total element |
| Elements | Limited to depositable metals (Pb, Cd, Zn, Cu, Hg, As, etc.) | Almost all elements |
| Field testing | Possible with a portable potentiostat | Not practical |
Recommended models
The Corrtest brochure recommends the CS300M, CS350M, CS310X and CS2350M for analytical electrochemistry.
| Product | Best for | Price | Purchase |
|---|---|---|---|
| Corrtest CS300M (no EIS) | The most economical option: DPV, SWV, NPV without EIS. | Rp 99.144.000 | Buy online |
| Corrtest CS350M (EIS to 1 MHz, ±2 A) | When the lab also does impedimetric sensing or corrosion. | Rp 167.884.000 | Buy online |
| Corrtest CS310X multichannel (option A, 4 channels) | Parallel analysis of many samples. | Rp 240.700.000 | Buy online |
| Corrtest CS100ME portable (Bluetooth) | Field monitoring. | on request | Request quote |
Store catalogue prices before 11% VAT and shipping; subject to change. Stock and delivery time are confirmed in the quotation.
Heavy-metal analysis package
Stripping Voltammetry Package
ASV for Pb, Cd, Zn and Cu in water and digested samples.
- Corrtest CS300MDPV/SWV strippingRp 99.144.000
- CS920 glassy carbon Ø2 mmWorking electrode (bismuth or mercury film)Rp 4.407.000
- CS901 Ag/AgClReferenceRp 2.149.000
- CS911 platinum plateCounterRp 4.131.000
- CS935 cell 50 mLMeasuring cellRp 2.204.000
- CS942 polishing kitElectrode polishingRp 4.958.000
Add a magnetic stirrer for the deposition step (see magnetic stirrer prices) and acetate buffer from the sodium acetate collection.
Frequently asked questions
Do I have to use a mercury electrode?
No. Bismuth-film electrodes on glassy carbon are widely used as a safer alternative for Pb, Cd and Zn.
Which metals can be analysed?
Metals that can be deposited and stripped, mainly Pb, Cd, Zn, Cu and Hg; arsenic and some others with special electrodes and conditions.
How long does one analysis take?
Typically 5–15 minutes per sample including standard additions, depending on deposition time.
Can it be used in the field?
Yes, with the CS100ME portable potentiostat, which has a built-in 10 Ah battery.
Need help choosing?
Tell us about your samples, methods and budget. Our team will put together the equipment and supplies with a formal quotation.
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