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An Automated Method for Analysis of Inorganic Arsenic
Species in Sediments and Tissues by HGAA
Leonard C. Pitts, Woods Hole Group Environmental
Laboratories
Ultra-Fast
Field Gas Chromatography for Site Characterization and
Field Monitoring
Michael A. Marando, M.S., GEI Consultants, Inc
Is
Method 1664A Silica Gel Treated N-Hexane Extractable
Material (SGT-HEM; Non- Polar Materials) a Measure of
Total Petroleum Hydrocarbons?
Dr. Michael W. Miller, New Jersey department of
Environmental Protection
Michael Wright, TRC Omni Environmental
Corporation
Alexander M. Allen, Tosco Corporation Bayway Refinery
Boguslaw Dubek, Tosco Corporation Bayway Refinery
Solid
Phase Microextraction: The Alternative to Purge and Trap
Michael Rossi, Seth Pitkin, Kim Watson, Stone
Environmental Inc.
Rapid
Screening and Analysis of Hazardous Chemical Agents in
Public Water Supplies and in-Coming Process Water
Robert Johnson and Stephen MacDonald, Horizon Technology
A
Comparison of Commonly Used Cyanide Analytical
Methodologies for MGP Site Applications
James
F. Occhialini, James C. Todaro, Joseph Clements, &
Elena Dayne, Alpha Analytical Labs, Eight Walkup Drive,
Westborough, MA 01581
Michael Rostkowski – Global Environmental Strategies,
LLC
William R. Swanson & Tamara Burke – Camp Dresser
& McKee Inc.
Measuring
Groundwater, Soil Vapor and Indoor Air to Evaluate Fate
and Transport: A Case Study
Denise A. Kmetzo and Lisa J. Campe, Woodard & Curran
An
Automated Method for Analysis of Inorganic Arsenic Species
in Sediments and Tissues by HGAA
Leonard
C. Pitts, Woods Hole Group Environmental Laboratories, 375
Paramount Dr., Raynham, MA 02767, Tel: 508-822-9300, Fax:
508-822-3288
Measurement
of arsenic species is becoming increasingly important in
environmental studies due to the varying toxicity of the
different arsenic compounds. LD50 studies indicate that
the inorganic arsenic species, arsenite (ASIII) and
arsenate (AsV) are far more toxic than the organic arsenic
species such as monomethyl and dimethyl arsenic. Methods
currently exist to determine arsenic species in
environmental samples but these methods can be labor
intensive, employing hydride generation followed by
cryogenic trapping and gas chromatography atomic
absorption (HG-CT-GC-AA), or utilize very expensive
equipment (HPLC-ICP MS) which can significantly add to the
cost of the analysis. Methods are presented here to
determine inorganic arsenic in tissues and arsenite and
arsenate in sediments utilizing an automated Perkin Elmer
FIMS 100 Flow Injection Hydride System with atomic
absorption detection. Inorganic arsenic is reduced to
ASIII prior to hydride generation with NaBH4,
followed by gas liquid separation, decomposition in a 900oC
quartz cell and analysis. Inorganic arsenic is leached
from homogenized tissue samples prepared by cryogenic cell
disruption and pulverization followed by extraction in 2 M
HCl. An intercalibration study on fish tissue utilizing
HG-CT-GC-AAS gave similar results and good matrix spike
recoveries were observed. Organic arsenic species are not
converted to inorganic arsenic during preparation. ASIII
and AsV are selectively leached from sediments with 0.1 M
H3PO4 and 0.1 M Na3PO4
respectively. Sediments and tissues are leached in an
ultrasonic bath for 24 hours and centrifuged prior to
reduction and analysis. A reporting limit of 0.01 mg/kg
wet weight is achieved for each matrix. Organic arsenic
compounds, which can from volatile hydrides, are removed
from the analysis with a trap containing graphitized
carbon black. Sample analysis time is about 3 minutes.
Ultra-Fast
Field Gas Chromatography for Site Characterization and
Field Monitoring
Michael
A. Marando, M.S., GEI Consultants, Inc., 1021 Main Street,
Winchester, MA 01890, Tel: 781-721-4107, Email: mmarando@geiconsultants.com
The
zNose™ Model 4200 analyzer is a field gas chromatograph
(GC) that is capable of analyzing volatile organic
compounds (VOCs) and semivolatile organic compounds (SVOCs)
to part-per-billion (ppb) levels in less than two minutes.
The analyzer is manufactured by Electronic Sensor
Technology of Newbury Park, CA and has a surface acoustic
wave (SAW) detector that can detect and quantify the mass
of VOC and SVOC compounds to picogram (10-12
gram) levels. This
capability allows for real-time decisions to be made in
the field and allows site managers to be more effective in
conducting site assessments by reducing time and costs. Soil
gas surveys can be performed to rapidly delineate the
extent of contamination at a site.
Soil borings and test pits can be better placed to
yield more useful data.
In addition, the zNose™ can be used to test the
effectiveness of remedial technologies in the field and
reduce the need for off-site analysis.
The zNose™ also has the capability to produce
VaporPrints™, a visual representation of the
constituents in the sample that allows for identification
of mixtures of chemicals.
VaporPrints™ can be generated for complex
mixtures of chemicals, such as diesel and gasoline, to
assist in environmental forensics.
Is
Method 1664A Silica Gel Treated N-Hexane Extractable
Material (SGT-HEM; Non- Polar Materials) a Measure of
Total Petroleum Hydrocarbons?
Total
Petroleum Hydrocarbons (TPH) is a non-specific parameter
that has been defined by EPA method 418.1and used for over
twenty years to estimate the contamination of the
environment by petroleum products.
The method is simple, inexpensive and
straightforward. Freon 113 is used to extract petroleum
from the matrix, treated with silica gel and then
determined by Infrared Spectroscopy.
Due to the implementation of the Montreal Protocol
production and importation of Freon 113 is now banned in
the United States.
The search for a replacement is underway.
US EPA method 1664A Silica Gel Treated N-Hexane
Extractable Material (SGT-HEM; Non- Polar Materials) has
been considered by many States as a replacement for method
418.1.
The New
Jersey Department of Environmental Protection has over
four hundred permits that require the determination of
Petroleum Hydrocarbons/ TPH.
The ConocoPhillips Bayway Refinery has a wastewater
discharge permit for Petroleum Hydrocarbons that specifies
the use of method 418.1.
The intent of this study was to determine if Method
1664A could replace method 418.1.
A major difference between the two methods is the
determinative procedure.
Method 418.1 is a direct instrumental measurement
of the dried extract.
Method 1664A is a gravimetric measurement that
requires heating the extract to remove the solvent. The
key question to be answered is; what carbon range
petroleum hydrocarbons are lost by heating the extract?
Method
418.1 determines diesel (#2 fuel oil) to #6 fuel oil,
approximate carbon range C 8 – C60. The use of this
method at gasoline site is not appropriate because 50-60%
of the material is lost during the analysis.
This paper presents the carbon range study for
Method 1664A. Hexane
solutions of normal hydrocarbons in the C8 – C14 range
were evaporated using the Horizon SPEED – VAPTM II
9000 Solvent Evaporation System. Seven individual aliquots
of each set of standards were subject to the evaporation
procedure at 28oC and at 45oC the
temperature specified by the SPEED – VAPTM procedure
manual. Another
study was done using a water bath set at 85oC
to obtain the distillation temperature of 70oC
recommended by method 1664A.
The mean
recovery of n-octane (C8) was negligible (less than 10%)
at each of the three temperatures. The difference for
recovery of n-decane (C10) and n-dodecane (C12) at the
three different temperatures was significant with higher
mean recoveries observed at 28oC (C12 77%).
The recovery of n-tetradecane and the winter diesel
standard at 28oC and 45oC were
similar 90 - 85%. The recovery of n-tetradecane and the
winter diesel standard at a distillation temperature of 70oC
were 70 – 60%. The
carbon range for winter diesel is about C12 to C30.
The study
shows that the recovery of petroleum hydrocarbons by
method 1664A is temperature dependent. Petroleum compounds
with carbon numbers as low as C12 can be successfully
recovered using the Horizon SPEED – VAPTM II
9000 Solvent Evaporation System, at an operational
temperature of 28oC.
Under this condition the method 1664A Silica Gel
Treated N-Hexane Extractable Material (SGT-HEM; Non- Polar
Materials) can be a replacement for method 418.1.
Since every discharge has different composition a
comparison study should be done.
Solid
Phase Microextraction: The Alternative to Purge and Trap
Michael Rossi, Stone Environmental Inc. 535 Stone
Cutter’s Way, Montpelier, VT 05602
. Tel: 802-229-2194, Fax: 802-229-5417, Email:
mrossi@stone-env.com
Seth Pitkin, Stone Environmental Inc. 535 Stone Cutter’s
Way, Montpelier, VT 05602, Tel: 802-229-2192, Fax:
802-229-5417, Email: spitkin@stone-env.com
Kim Watson, Stone Environmental Inc. 535 Stone Cutter’s
Way, Montpelier, VT 05602, Tel: 802-229-2196, Fax: 802-229-5417, Email: kwatson@stone-env.com
Solid Phase Microextraction (SPME) is an alternative
to the more traditional purge and trap sample preparation
technique for volatile organic compound (VOC) analyses.
SPME offers a faster, more field friendly and less
expensive technique than the purge and trap method. SPME
offers precision and accuracy equal to the purge and trap
technique. These features make SPME the method of choice
for high quality/high quantity data that are integral to
the success of today’s site investigations. SPME
consists of a simple and relatively inexpensive
phase-coated fiber that, when exposed for a given amount
of time to the sample, allows for the analytes to
partition onto the fiber. The fiber is then placed into
the GC injection port to allow for thermal desorption and
transfer of the analytes onto the GC column. The method is
accepted by the American Society for Testing and Materials
(ASTM) as a sample preparation method for VOCs and
semi-volatile organic compounds (SVOCs) in water samples.
The technique can be applied to water, soil and air
analyses. Due to the relatively inexpensive SPME
instrumentation and the fact that an SPME extraction is
typically performed in under ten minutes, the cost and
speed of the SPME technique are a fraction of those of the
purge and trap technique. Two confirmation studies
involved having duplicate samples sent to a fixed lab for
gas chromatography/mass spectrometry (GC/MS, Method 8260)
analyses and comparing the results to the field lab’s
SMPE/GC results. The paired analytical results for the
water and soil samples were found to compare extremely
well; the overall average relative percent differences (RPD)
for the water and soil analyses were 27 and 25,
respectively. A performance-based evaluation of the SPME
technique indicated the SPME method can be used to produce
fully defensible data, as defined using the EPA’s SW846
8000 guidelines and acceptance criteria.
Rapid
Screening and Analysis of Hazardous Chemical Agents in
Public Water Supplies and in-Coming Process Water
Robert
Johnson and Stephen MacDonald, Horizon Technology, 8
Commerce Drive Atkinson, NH
03811, Tel:
603-893-3663
With the recent concerns of hazardous chemical agents
possibly being introduced into public water supplies and
in-coming process water, there is a greater need for a
rapid screening technique to detect these agents, before
serious health issues can arise. One approach is to develop a quick and sensitive, qualitative
screening method, which would allow many water samples to
be analyzed quickly, to determine if there are any
chemical agents present.
The desired goal of one major drinking water
facility was to be able to process and analyze 100
samples, in a 2 hour turnaround time period.
The first step in proving if this goal of fast analysis with
low detection limits was possible was to run various
classes of compounds, and ensure the compounds could be
extracted at expected target levels.
The classes of compounds tested were Acids, OCP’s,
OPP’s, PCB’s, Neutrals, Phenols, and Hydrocarbons.
An automated SPE disk extractor system, along with
a novel drying procedure was used.
No concentration of the final extract was
performed. Once
each of these classes of compounds was determined
individually, at the desired detection limits, all of the
classes were mixed, and the sample analyzed.
Using a LECO Pegasus Time of Flight MS system (TOF),
all of the compounds were detected, and at the desired
detection limits.
This paper will review the analytical conditions used to
extract and analyze these test samples.
Detection limits of each compound will also be
presented. In
addition, an explanation of the sampling technique
proposed will be explained.
A
Comparison of Commonly Used Cyanide Analytical
Methodologies for MGP Site Applications
James
F. Occhialini, James C. Todaro, Joseph Clements, &
Elena Dayne, Alpha Analytical Labs, Eight Walkup Drive,
Westborough, MA 01581
Michael Rostkowski – Global Environmental Strategies,
LLC
William R. Swanson & Tamara Burke – Camp Dresser
& McKee Inc.
Two
groundwater samples collected from a known manufactured
gas plant (MGP) site and a laboratory reference sample
were analyzed in triplicate using a series of cyanide
analytical methodologies.
The groundwater samples were representative of site
conditions and had differing concentrations of total
cyanide present. The
reference sample was prepared by adding a known
concentration of potassium cyanide and ferric ferrocyanide
to laboratory regent water.
The
two samples, along with the reference sample were analyzed
in triplicate using the following methodologies:
¨
total cyanide (SM 4500-CN-CE)
¨
cyanide amenable to chlorination (SM
4500-CN-CEG)
¨
weak acid dissociable cyanide (SM
4500-CN-I)
¨
physiologically available cyanide (MA
DEP)
¨
free cyanide (SM 4500-CN-E)
The
results, as well as observations and interpretation are
presented with special emphasis placed on the usefulness
of the data for MGP Site project applications.
Measuring
Groundwater, Soil Vapor and Indoor Air to Evaluate Fate
and Transport: A Case Study
Denise
A. Kmetzo and Lisa J. Campe, Woodard & Curran, 980
Washington Street, Suite 325, Dedham, MA
02026, Tel: 781-251-0200, Fax: 781-251-9256
The
transport of chlorinated volatile organic compound (VOC)
vapors from groundwater into occupied buildings is of
concern, as indoor air concentrations of these compounds
may present risk to occupants.
Often, indoor air concentrations are not measured
and we rely on transport models to estimate indoor air
concentrations based on groundwater or soil gas
measurements.
We evaluated residences in a neighborhood that had
groundwater impacted with chlorinated VOCs.
We collected groundwater samples from various wells
around the neighborhood, and collected two rounds of soil
vapor and indoor air data from over 30 residences.
Some of the residences were located over the plume
and others were not located over the plume.
In addition, ambient air samples were collected on
each sampling day from the neighborhood.
We present the inter and intra-medium
concentrations that we detected, as well as the data
patterns that described the transport of the VOCs.
We also describe how the transport conclusions
compared to conclusions that would have been made if only
fate and transport modeling had been performed.
In addition, we present the correlation of measured
indoor air concentrations to ‘background’ indoor air
concentrations and how indoor or ambient sources may have
affected the indoor air results.
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