Empore particle-loaded

Empore 3M Particle-loaded membranes, disks PIPE, PS-DVB, silica lEX, AF... 

Particle-loaded membrane extraction disks, the so-called Empore disks, form an alternative to SPE cartridges [27, 78-79]. With Empore disks, higher sampling flow-rates are possible. They show excellent sorbent capacity. Recoveries at 0.1-pg/l level... 

A novel device was designed to estimate the dislodgeability of dust-associated pesticide residues by skin contact (Edwards and Lioy, 1999). Called the EL Sampler , the device consists of a spring-loaded assembly that permits the sampling medium to be pressed lightly (12g/cm or 1160 Pa) onto the surface to be monitored. A 10-cm x 15-cm Empore C-18 extraction membrane was used for the sampling medium. The material was chosen after controlled experiments on particle adhesion showed it to pick up the same distribution of test dust particle sizes as the human hand. In studies in which the EL sampler was pressed onto polyethylene surfaces coated with house dust and then sprayed with a solution of pesticides in 2-propanol, the device was found to collect 35%, 31 %, 32% and 18 %, respectively, of chlorpyrifos, diazinon (0,0-diethyl 0-[6-methyl-2-(l-methylethyl)-4-pyrimidinyl] phosphorothioate), malathion and atrazine (6-chloro-A -ethyl-A -isopropyl-l,3,5-triazine-2,4-diamine). Parallel studies with human hand presses (full hand at 6.8 kg = ca. 6900 Pa) yielded collection efficiencies of 42 %, 29 %, 43 % and 21 %, respectively. 

PTFE membranes loaded with particles of silica gel or chemically bonded silica gel are a relatively new type of flexible support developed for TLC (97-99). These Empore sheets, which are similar to Empore extraction disks used for solid phase extraction (100), are especially useful for recovery of separated samples in preparative layer chromatography or scintillation counting of radioisotopes by cutting out sections of the chromatogram containing the analytes of interest. Empore sheets have lower efficiency than conventional thin layers (29) and have not yet been applied widely for TLC. 

---