This powerpoint presentation begins by providing a brief overview of the problem of domestic wastewater periodically contaminating
drinking water systems through
cross-connections and
pressure transients (backflow).
Grab sampling and indicator bacteria
(e.g., Total coliform, E. Coli) to monitor fecal
contamination is unable
to detect episodic contamination of the
system. The main goal of the study was to
prove the efficacy of using polymeric
and macroreticular styrene-based resins
to capture very low levels of organic
contaminants from large volumes of
water over an extended period. Specific research objectives included the following:
develop and test a sorbent cartridge for
capturing specific trace levels of caffeine
from drinking water;
develop a Solid Phase Extraction (SPE)
analytical method for analysis of caffeine
detection;
determine caffeine recovery efficiencies and
detection limits on the sorbent; and,
develop a field apparatus. The proposed method involved
building on existing Solid Phase Extraction
(SPE) methods, and
on-line integrative sample (continuous
monitoring at low flow rate through
parallel SPE columns). Presentation conclusions indicate the following:
ENVI-Chrom P and Oasis® HLB sorbents were
more appropriate for SPE of caffeine from large
volume of water sample (e.g., 100 L);
very high background of interferences from
large volume of actual water samples was prime
concern in detection of targeted contaminants
(e.g., caffeine);
clean up of extracts with LC-Si and Florisil SPE
tubes reduced the background interferences to
half with slight improvement in the
chromatograms; use of pre-column of XAD-2 before the columns
with ENVI-Chrom P sorbent also improved the
chromatograms with reduction in background
interferences;
the study with simulated contaminated sample
showed good recovery of caffeine to the level
of 99 %;
method detection limit (MDL) of 0.69 ng/L was
obtained in this study; and,
field apparatus was built and used successfully
in the field. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 820 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 25 |
| Published : | 11/01/2008 |
