Your TRPH Oil Range Organics Standard?

[LALman]

Question: What stock Oil Range Organics standard are you using for 8015 GC-FID ORO calibration?

We decided to do an ORO calibration to run alongside our DRO calibration. Here in CO, DRO is defined as C10-C28 and ORO is defined as C29-C35. That ORO range is pretty narrow. I got in a standard from AccuStandard (Cat#FU-018-H-40X SAE 30W Motor Oil 1x1mL) of 20mg/mL 30-wt oil. This is a surprisingly narrow range oil! We want to calibrate up to 10,000 ppm. So we tried getting several straight 30W oils from auto stores. Penzoil 30W seems to be the closest but still has a far wider carbon# range than the AccuStandard oil. This means that a 1000ppm prepared from the AccuStandard oil reads ~2700ppm versus the Penzoil. This is outrageously bad. So we tried AccuStandard cat#D-3524-QC-10ML which is a D-3524 Mid Level Daily QC
Solution of 95% 30-wt and 5% Diesel#2. This oil is fairly close to the 30W Penzoil but not the same and a curve built from it fails to be accurate for the AccuStandard (Cat#FU-018-H-40X SAE 30W Motor Oil 1x1mL).

Any suggestions for a oil source would be welcome. I would prefer to avoid those dissolved in methylene chloride.

[cjm]

We use AccuStandard part "DRO-A-102-LCS-10X-R1" for calibration of DRO C10-28. This is just diesel fuel but should give a good calibration for C10-C28. Part D-3524-CAL-01-5ML has both diesel and motor oil but is part of a set. They may have a product you could use for up to C35.