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8270 SVOA Internal Standard from Neat Compounds
Posted: Mon May 20, 2013 4:01 pm
by Darber99
Has anyone ever made their own Internal STD for EPA8270 from neat compounds? I'm trying to make a 4000ppm SV Internal standard solution in DCM and everything goes into solution fine except for Perylene-d12. Even after 25 minutes of sonication, I still have some undissolved powder in the bottom of my volumetric flask. A last ditch effort seems to be heating the solution up to almost boiling and hoping the remaing solid dissolves, but I'm worried about losing some of my low boilers (1,4-DCB-d4, Naph-d8). Any suggestions? Thanks for your time.
Re: 8270 SVOA Internal Standard from Neat Compounds
Posted: Thu May 30, 2013 1:43 pm
by Yama001
Our folks do it routinely - they tell me they just use an ultra-sonic bath. That being said, I often see lousy variations in the internal standard mixes they make up, so I bet they have more trouble with this issue than they will admit.
Re: 8270 SVOA Internal Standard from Neat Compounds
Posted: Thu May 30, 2013 6:52 pm
by Darber99
Thanks Yama. That's exactly what I've been doing but it takes about 20-30 minutes of sonication and a good half day sitting at room temperature for all the Perylene-d12 to dissolve back into solution. Guess I should just be happy it does.
