Spectroscopy for DBP Monitoring (2002,
order #90888/project #2563). The study
further explored less expensive and complex
methods for the detection of various DBPs.
Differential absorbance spectroscopy (DAS)
was used for the analysis of individual
DBPs and total organic halogen (TOX).
The concentrations of stable DBP species
formed were correlated with DAS (at 272 nm
wavelength) at all pH conditions studied ( 6.0,
7.0, 8.0). Most of the DBPs were detectable
at single-digit µg/L levels. The concentration
of TOX formed during chlorination or
chloramination was strongly and linearly
correlated with DAS but no correlation was
found with water dosed with chlorine dioxide.
The Foundation has also funded research
aimed at optimizing analytical methods for
HAAs. Development of an Experimental
Procedure for Haloacetic Acids Using
Ion Chromatography (2000, order/
project #163) investigated several extraction
techniques and an ion-chromatographic
method for parts-per-billion detection
of HAAs in drinking water. The project
determined that although the method
detection limits were adequate, the nine
HAAs interferences from sulfate could not
be completely suppressed.
Many researchers have sought alternative
methods for analyzing HAAs, because
the currently approved method is time-and chemical-intensive. Application
of ESI-FAIMS-MS to Drinking Water
Contaminant and DBP Analysis (2004,
order/project #2640) applied a unique
analytical instrument to the measurement
of HAAs and other organics in water. The
instrument is known as electrospray
ionization–high field asymmetric
waveform ion mobility spectrometry–mass
spectrometry (ESI–FAIMS–MS). The
researchers were able to detect HAAs at the
0.1 to 0.6 µg/L level without derivatization.
Development of a Novel Method for the
Analysis of Haloacetic Acids in Drinking
Water (2004, order #91013F/project #2644)
used capillary electrophoresis for
the analysis of HAAs. The method
employed solid phase extraction for
sample preparation. Detection was in
the low ppb range for all HAAs except
chlorodibromoacetic acid, which co-eluted
with an unknown contaminant. The project
resulted in a robust method of analyzing
HAAs that does not require lengthy
derivatization, with sensitivity comparable
to the existing USEPA method.
Methods for Real-Time Measurement of
THMs and HAAs in Distribution Systems
(2004, order #91003F/project #2873) was
funded by the Foundation to develop faster
methods for the analysis of THMs and
HAAs. Faster methods are necessary for
the detection of short-time variations and
transient peaks in DBP formation.
Phase 1 of the project was a very extensive
literature review of existing analytical
methods. The methods were classified
according to cost, expertise required,
detection limit, recovery, relative standard
deviation (RSD), equipment required,
analysis time, and adaptability to online
monitoring. Criteria for the ideal method
were identified as low detection limit
(< 5 µg/L), minimum of one sample per
hour throughput, portability, and ease of
use. The project concluded that none of the
existing known methods for THM and HAA
analysis could be considered close to the
ideal method defined in the project.
Phase 2 of the project (2007, order #91173/
project #2873) selected several technologies
for testing and comparison with approved
methods. THMs were analyzed via
three methods: capillary membrane
sampling gas chromatography (CMS–GC),
