VODASPEC is the first online multi-elemental trace metals analyzer for monitoring heavy metals in water with sub-ppb detection limits without sample preparation or reagents.
VODASPEC Applications
- Provide baseline contaminant data during water treatment at drinking water facilities and municipalities.
- Provide on-line and remote monitoring of metal contaminants along the way from water supply source to point of use as part of a network of analyzers.
- Provide early warning during accidents including spills in fresh water supplies and reservoirs.
- Support waste-water remediation process control and optimization and monitor process effectiveness over time.
- Monitoring water supply used for food and beverage production process.
VODASPEC Features
- Sub-ppb detection limits
- Simultaneous analysis across UV and Visible spectral range
- Fully autonomous with automated data handling
- Reagent-free analysis with no sample preparation
- High-throughput analysis
- Matrix independent determination
Basic Principles of Operation
The instrument can sample the water in either open- or closed-loop mode and simultaneously pre-concentrate the analytes on the surface of a cathode. The pre-concentration step not only removes the analytes from their concomitant matrix (hence a matrix-free determination), but also provides a programmable sensitivity and dynamic range where the pre-concentration can be adjusted based on the sensitivity needed for an application. A synchronous pulse-modulated spark produces characteristic atomic emission and an on-board spectrometer integrates the collected spectra during analysis to enhance signal-noise ratio.
Calibration and Linearity
Long-term calibration stability is crucial for autonomous systems designed for field deployment. VODASPEC analyzer takes advantage of an automated and reagent-free self-cleaning technology to eliminate sample carry-over and improve instrument signal stability. Since analyte pre-concentration can be accurately controlled, the dynamic range of the system can be readily optimized for applications with different sensitivity requirements. In practise, even a one-point calibration can be used with reasonable accuracy.
Examples of simultaneously acquired analyte signals for Cd, Hg, Pb, and Cr in a 10-ppb spiked drinking water sample with average hardness of 125 mg/L.
Examples of simultaneously acquired calibration curves for Cd, Hg, Pb, and Cr in a drinking water sample with average hardness of 125 mg/L. The concentration range was intentionally chosen for environmental and regulatory applications.
Graphical User Interface
VODASPEC utilizes a workflow-based user interface designed with simplicity in mind. The system can be accessed, programmed, and controlled remotely through a network server and an internet browser. This makes VODASPEC an ideal system for applications where a network of analyzers at different locations are deployed.
Specifications
Performance
| Detection limits (ppb) | Sub-ppb to sinlge digit ppb for majority of elements including Pb (0.4), Hg (0.05), Zn (0.4), Cd (0.04), Cr (0.3), Ni (0.2), Mn (0.3), Co (0.2), Cu (0.1), Ag (0.3), Au (0.2), Pd (0.5), Pt (9), Rh (2), Bi (4), In (0.2), Ba (4), Sb (0.2), Sn (4), Tl (4), V (0.6) |
| Precision | <10% RSD |
| Accuracy | <±10% (with no internal standards correction) |
| Conc. dynamic range | Minimum 2 orders of magnitude; extendable using programmable sensitivity option. |
| Total analysis time | 5-30 min. depending on sensitivity required |
| Spectral range | 200-730 nm |
| Spectral resolution | 0.5 nm |
| Min. sample volume | 50 mL (in closed-loop mode) |
| Max. sample flow rate | <2 L/min – adjustable by internal pump |
| Max. sample pressure | 120 psi |
| Application software | VODASCAN®; Windows® OS (PC and Tablet) |
| Electrical power | 90-265 VAC 50/60 Hz; <100 W (at peak consumption) – Operation with renewable 12-24VDC supply also configurable. |
| Communication | USB (standard), optional: WiFi, Bluetooth, GSM (SIM card) |
| Mounting | Wall-mount or stand-alone |
| Dimensions (W x H x D) | 18” (45.7 cm) x 18” (45.7 cm) x 6” (15.2 cm) |