17 seconds is all it takes to filter a 40 mg/L OPR and achieve 98% recovery with the Xenosep SPE Filters for EPA Method 1664A. That’s 50 times faster than a typical single layer SPE filter with 89% recovery. In addition, triple layer Xenosep SPE Filters have 5 times the filtration capacity already built-in for the MS, MSD, and hard-to-filter samples. Xenomax Triple layer SPE filters for Method 1664 are designed for moderately ditry samples. Use the Xenomax Prefilters with dirtier samples.