Question/Answer
Is the hexane recovered and/or does it need to be under a hood?
The unit is self enclosed and does not need to be used under a hood. It has a ventilation duct that does need to be routed into a fume hood or other exhaust system. We currently do not have any way to recover the hexane during the evaporation step.
Do you do demos for the oil and grease analyzer.
We are not doing any individual lab demos at this moment. We do have a tech tip video that shows the operation of the unit and some of its advantages. You can see that by selecting the appropriate link at http://www.envexp.com/video. If you have further questions please contact a member of the sales team.
we get our sample volume after we run it, is this going to be a problem with the software?
No, that will not present any problems. The software does not do any of the sample calculations for you at this time. It only tracks the method and conditions used to do the actual extraction. The operator must separately track and calculate the pan weights, sample volume, and final result.
How often do you have to change the drying cartridges and how much are they?
The drying cartridges are single use only. Please consult the SPE-XPress accessories page (http://www.envexp.com/component/envexp/1-Wet_Chemistry/SS-Oil_and_Grease_EPA_1664/SPEX2-SPE-XPress_Accessories/G1065-SPE_-_5_5_Gram_Na2SO4_Drying_Cartridge%2C_50pk)or call any member of our sales team to find the current pricing on the cartridges.
Will this work with metallic powders that are being analyzed for oil and grease?
This system is not designed for use with solid matrices. A soxhlet extraction would be more applicable.
How about the sample with lots of suspended solid? Will they be filtered porperly? How Is sodium sulfate tube drying efficiency?
The instrument uses a liquid level sensor in the sample bottle to determine when all sample has been filtered. The filtration step will continue until that sensor detects no more free liquid in the sample container. If the sample contains large amounts of suspended solids you may experience an extended filtering cycle, but the instrument will filter all of it. In our testing we tried to find a sample with enough solids content that would halt the filtering process but every one finished. The sodium sulfate tubes contain 5.5 g of the salt and are just as efficient as that amount of salt would be under normal circumstances. I believe the molar ratio of sodium sulfate to water absorbed is 10.
What is the typical time from start to finish for a O&G measurement?
This certainly will depend on how turbid of a sample you are dealing with but a good average total time from start to finish would be around 50 - 60 minutes.
How dirty was the sames used in this system? Are you using a wide mouth jar?
The beta testing site was a municipal water treatment plant so the turbidity of the samples tested varied greatly from relatively clean to very turbid (effluent and influent samples). The jars used are the ones mentioned in method 1664 though adaptors are available for other sized openings.
How does this system measure sample volume?
The unit does not measure sample volume. The sample volume is user-defined and must be input into the software program as one of the steps before running the extraction procedure.
We use wide-mouth sample jars. Do you have an adapter? I don\'t see any solvent jars. How is the solvent delivered or are they just not hooked up in the picture?
Adaptors are available for other size sample jars. Contact us at info@envexp.com for specific sizes. Solvents are added using nitrogen to create a positive pressure for injection. This is not pictured on the web but if you look at the technical data sheet you can see a drawing of where the nitrogen line is hooked up and where the reagent inlet lines are located.