Filter Aids??

[Bigbear]

We are looking for a pesticide in 525 that was sprayed inside dwellings. We have been using a modification of 525 using 47 mm disks with very good success, except for some samples, Samples are collecectes w/ meoh soaked cotton balls ( not our idea). Most samples extract and elute well except for the ones that look like water after latex paint brush cleanning. These would not go through the disks. We are planning to try doing these samples in a sep funnel with MeCl2.
Any ideas ??

[jkubeika]

For fine sediment samples we use a 5 micron and then a 1 micron prefilter over the disks for SPE extraction with screens inbetween to prevent clogging, then filter aid on top of disk directly.

Which pesticide are you looking for? We do 525.2/508.1 by SPE and 625 by CLE or sep funnel when stuck for time. The sep funnel extraction looses most of the phenols though.

[Bigbear]

chloropyrifos
Where do you get the clean up disks?

[Don Shelly]

I hate to be commercial on the forum, but UCT has a cartridge for 525 that will work without the need for expensive filter aid. Placing a small wad of deactivated glass wool in the cartridge prior to conditioning is all that is needed. The product will not plug.

Don

[Yama001]

That sound like a great product Don. When we did those types of disk extractions, the diatomaceous earth filter aid worked great, but the cost was high.

[Don Shelly]

That sound like a great product Don. When we did those types of disk extractions, the diatomaceous earth filter aid worked great, but the cost was high.

Thanks for the diatomaceous earth tip!

Don