Teledyne Leeman Labs completed a study using its Hydra IIC mercury analyzer in Volatile Hydrocarbon (VHC) mode to determine the total mercury in kerosene. We published a technical note that demonstrates the capabilities of the Hydra IIC to determine the level of mercury by direct combustion of the kerosene. The system was also configured with an enhanced moisture control system.
The Hydra IIC is an independent standalone analyzer that uses Cold Vapor Atomic Absorbance (CVAA) spectroscopy to obtain reliable quantitative data from simple to complex matrices by direct combustion combined with a proprietary catalyst to remove interfering compounds such as sulfur and nitrogen oxides. The biggest advantage of the Hydra IIC is that no sample preparation is required before analysis. And, because no sample preparation is required; the cost and hassle of dealing with waste disposal is avoided.
A weighed sample (~80 mg) of kerosene is introduced into the Hyrda IIC and the uninterrupted analysis is completed in 13 minutes; five of which is waiting in between samples while the furnace cools to an injection temperature that will avoid sample auto-ignition during the injection phase.
Direct analysis of Hg via Thermal Decomposition is described in methods such as USEPA 7623, 7473 and ASTM 6722.
For additional details on the instrumentation, method parameters, calibration and results, download the associated technical note, HG/PC-1702.
Summary of Procedure:
- Add ~100 mg of diatomaceous earth to a nickel boat
- Tare boat(s) and add sample(s) into boat(s) – max. weight of 80 mg
- Load boats onto the sample boat shuttle
- Run Hydra IIC in VHC mode using an automated sequence
Conclusion
The study concluded that the QC recoveries demonstrate the Hydra IIC system is in control and stable. The calculated MDL for the system under the conditions described in the technical note, is less than or equal to 0.39 ng/g, therefore all the kerosene values would be less than a typical LOQ.
The spike consisted of 77 mg kerosene and 6 mg of 100 ng/g oil standard. At a 100% recovery value, the ng/g value would have been 7.68 with a weight corrected value (0.083 g) of 0.48 ng/g contribution from Kerosene and 7.2 ng/g from the oil standard.
The Hydra IIC in VHC mode is an ideal system for determining the concentration of mercury in light to heavy petroleum distillates.
Download the petrochemical industry technical note for a complete summary of the analysis.