This should give you an overview about the requirement and the advantages of the systems compared to the older generations.
2018+
| Energy consumption | 0.50 kWh (initial) 0.45 kWh (continuous) |
| Environment temperature | 18 - 30 °C (stable temperature 1 °C is required for high sensitivity) |
| DOCOX / DONOX reactor | 2x Electronic ballast with 30 W |
| Thin film reactor | Electronic ballast with 35 W |
| Carrier gas | Nitrogen 4.0 or 5.0, about 10 L/h |
| Mobile phase | Phosphate buffer (22.5 mmol), pH 6.59, about 2 L in 24 hrs |
| Acidification solution | Phosphatic acid, pH 1.5, about 0.8 L in 24 hrs |
| Measuring range DOC (bypass) | < 1 - 5000 ppb (org. Carbon) |
| Measuring range LC-OCD | < 1 - 5000 ppb (org. Carbon) |
| Detection limit LC-OCD | < 1- 50 ppb (org. Carbon, compound specific) |
Pro’s and Con’s of the Model 9 generation compared to Model 8:
- Higher sensitivity, depending on detector but at least two times
- Lower Nitrogen consumption
- Halfed measurement time of only 70 minutes per analysis
- CE – certification with tested electrical parts
- Improved and more efficient electrical systems
- High standards of safety concerning UV and electricity
- All over digital data collection using ethernet, resulting in no overshoots
- Improved cooling devices and more efficient removal of moisture
- Detection of urea using the new standard setup
- Simplified side panel for easier maintenance
- Connection port for cleaning DONOX reactor without opening the system
- “Closed” ethernet network, advantage and disadvantage at the same time
2008-2017
| Energy consumption | 0.4 kWh |
| Environment temperature | 18 - 30 °C (stable temperature 1 °C is required for high sensitivity) |
| DOCOX / DONOX reactor | 2x 990 V, 40 mA |
| Thin film reactor | 990 V, 160 mA |
| Carrier gas | Nitrogen 4.0 or 5.0, about 30 L/h |
| Mobile phase | Phosphate buffer STD = 28 mmol, pH 6.59, about 2 L in 24 hrs |
| Acidification solution | Phosphatic acid, pH 1.5, about 0.8 L in 24 hrs |
| Measuring range DOC (bypass) | < 1 - 5000 ppb (org. Carbon) |
| Measuring range LC-OCD | < 1 - 5000 ppb (org. Carbon) |
| Detection limit LC-OCD | < 1- 50 ppb (org. Carbon, compound specific) |
Pro’s and Con’s of the Model 8 generation compared to older systems:
- Smaller footprint. (60×60 cm)
-
Organic Nitrogen Detector (OND) is now an integral part of the system
-
Less components (e.g. 1 HPLC-pump instead of 3 pumps is required)
-
Reduced analysis time (from 3 hrs to 2 hrs or less = 12 samples/day instead of 8 samples/day)
-
Autosampler with 36 positions for uninterrupted 5-day operatio
-
10 L mobile phase flask allows unattended operation of systems for 5 days (120 hrs)
-
System may be used as process instrument for quasi-continous on-line monitoring
-
Much more simple operation of system (“One-Button-Instrument”)
-
40% higher sensitivity for OCS (detection limit < 1 ppb)
-
40% less consumption of electricity (only 350 VA)
-
30% less consumption of nitrogen carrier gas (only 200 scm/min)
-
A 50-L bottle lasts for about 5 weeks
-
Manual injection device for ”quick” TOC-measurements during standard operation
-
Software for data acquisition and autosampler is now custom-made by Doc-Labor on LabView basis
-
Except for Windows Office no additional software is required
-
External ports for additional detectors (e.g. fluorescence) and fraction collector
-
Last not least: The new system looks much better than its precursors
The only disadvantage of ”Model 8”:
The ”TOC”-parameter is not anymore measured during standard operation. Only ”DOC” is measured.
Why?? Mainly out of 3 reasons:
- For correct analysis of POC (Particulate Organic Carbon) samples have to be homogenised immediately prior to injection. For automated operation this would require stirring bars and magnetic stirrers for each vial port. Such a feature would be extremely costly to realise.
- The UV-detector (254 nm) has a built-in narrow capillary which may get blocked.
- Our UV-based oxidation process may not be able to oxidise POC fully (for particles the UV-exposure time of 3 min in the thin film reactor may not be sufficient).
Nevertheless, there is still the option to measure TOC manually.