EPA Method 530 UCMR4

Discussions about sample preparation: extraction, cleanup, derivatization, etc.

3 posts Page 1 of 1
Hi,
I'm having poor recovery for o-Toludine in my SPE for method 530. Anyone running this method and willing to share info??
Are you rinsing your sodium sulfate with acetone? Acetone is necessary to release all of the o-toluidine.

Don
Don Shelly
LGC Standards
I just ran it exactly as the method state for solvent usage by the Oasis cartridges. Drying time I extended. The more moisture in the extracts the lower the recovery it seems, just don't over dry. I made several runs using different dry times and also tried drying with the positive pressure manifold mentioned in EPA541. There is a sweet spot you can find that will improve recoveries, also be certain to rinse the bottles as noted and pass through the lines into the cartridge.

Also, turn off the flow as soon as the bottle is empty, leaving the line full of water before the water rinse step, otherwise it takes a lot more vacuum to get the flow going again before the final DI rinse. I also do this with the first rinse with DI, and leave the cartridge full to the top before inserting the lines to draw the sample from the bottle, this way you cartridge remains full almost to the level of the end of the transfer lines. I elevate the bottles so that the bottom of the bottle is even with the lid of the extraction manifold so the sample transfers mostly by siphon once the flow is established, that way any micro leaks will not draw in air and let the water level go below the top of the packing material during extraction.
The past is there to guide us into the future, not to dwell in.
3 posts Page 1 of 1

Who is online

In total there is 1 user online :: 0 registered, 0 hidden and 1 guest (based on users active over the past 5 minutes)
Most users ever online was 1117 on Mon Jan 31, 2022 2:50 pm

Users browsing this forum: No registered users and 1 guest

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food & Beverage, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry