October 2008 | Volume 5 | Issue 3

FEATURE ARTICLE:

A Dissolved / Particulate Baseline Study of PAH’s in Particulate Laden Water

Poly Aromatic Hydrocarbons are of great environmental concern due to their carcinogenic impact. When water samples are extracted and analyzed for the PAH’s, many methods require the water sample to first be filtered, such that the particulate matter is removed. Filtration is required when conventional Solid Phase Extraction (SPE) cartridges are used for extracting the sample because SPE cartridges will easily plug when any particulate matter is present. With Liquid Liquid Extraction (LLE) techniques, emulsions typically create problems which could adversely impact the proper extraction of the suspended material.

However, compounds such as PCB’s and PAH’s will come out of the dissolved phase and adsorb onto the surface of the suspended particulate matter in the water column. Therefore, to determine the actual concentration of PAH’s in the water sample, the “whole” water sample with the suspended particulate matter should be processed. As many water samples extracted for PAH’s are surface water, river water, ground water, waster water, or water with suspended material, it is desireable to have a analytical method that can handle the “whole” water sample.

Download this Application Note.

DID YOU KNOW:

Dirty Samples Slowing You Down?

Samples laden with fine particulates can quickly clog SPE disks, slowing or even stopping sample processing. For most samples, using a Pacific Fast Flow Prefilter will dramatically improve the flow rate; however, the worst samples will even clog the prefilter.

To ensure that no sample gets left behind, Horizon Technology has developed an ultra fine stainless steel screen to keep the fine particulates, like clay, algae and food products from entering the pores of the prefilter and disk. The stainless steel screen is simply placed on top of the prefilter and disk. The disk holder is then assembled as normal. After the sample has processed, the stainless steel screen is reusable after a quick cleaning.

In a flow study, adding the screen on top of the prefilter and disk allowed a one liter sample with fine particulates to pass in 30 minutes. The identical sample with no stainless steel screen slowed to a near standstill after 20 minutes and was eventually aborted after 1-½ hours with ½ liter of sample left.

A technical tip detailing the use of the stainless steel screen can be downloaded here.

Ordering Information:
The 47mm screen is part number 31-0454; and the 47mm Pacific Fast Flow Prefilter is FFP-47-HT. The 90mm screen is part number 31-0457; and the 90mm Pacific Fast Flow Prefilter is FFP-90-HT. To place an order call 1-800-997-2997, extension 618 or email orders@horizontechinc.com

If you have any questions about this or previous "Did You Know" topics please contact support-service@horizontechinc.com