Groundwater Analytical has established and maintains a
corporate Quality Assurance Plan (QAP). The corporate Quality
Assurance Plan establishes an integrated plan of quality
control procedures and laboratory operational policies to
assure that the data generated by the laboratory is of known
and accepted quality.
All employees of Groundwater Analytical are responsible for
knowing the contents of the corporate Quality Assurance Plan.
Each employee is obligated to carry out his or her daily
tasks in accordance with the operational policies outlined in
the Quality Assurance Plan, and the written Standard
Operating Procedures of the laboratory.
Sample Receipt and Custody
Upon receipt by Groundwater Analytical, all samples proceed
through an orderly processing sequence specifically designed
to ensure continuous integrity of both the sample and its
documentation.
All samples are received and inspected by the Sample
Management section of Groundwater Analytical's Client
Services Department. All samples received by the laboratory
require an appropriate Chain of Custody form and work order.
Each sample is carefully checked for damage, correct label
identification, complete work order documentation, and
compliance with regulatory container, preservation and
holding time requirements.
Preparation Batch Quality Control
All samples are processed in batches of samples of the same
matrix requiring the same method of analysis. A sample
preparation batch consists of 20 or fewer samples that are
processed.
For most organic analyses, each sample in a sample
preparation batch is spiked with a surrogate compound(s), as
specified by the applicable methodology.
For each sample preparation batch processed, the laboratory
also analyzes several quality control samples. Typically, the
laboratory analyzes a blank, a laboratory control sample, a
matrix spike sample, and a sample duplicate with each sample
preparation batch. Specific analytical methods may have
additional preparation batch quality control requirements.
Preparation Blanks consist of reagents specific to the
method being employed that are carried through every
aspect of the procedure, including preparation, clean-up,
and analysis. Preparation blanks are analyzed to assess
the level of background interference or contamination
that exists in the analytical system which might lead to
the reporting of elevated concentration levels or false
positive data.
Laboratory Control Samples are aliquots of reagent water
or sodium sulfate spiked with a group of target compounds
representative of the method analytes, and carried
through every aspect of the procedure, including
preparation, clean-up, and analysis. Laboratory control
samples are analyzed to monitor the accuracy of the
analytical procedure, independent of matrix effects.
Control limits for accuracy for each analyte are based on
the criteria established in the applicable methodology,
or the historical data of the laboratory
Matrix Spike Samples are aliquots of client-supplied
environmental samples that are spiked with target
compounds representative of the method analytes, and
carried through every aspect of the procedure, including
preparation, clean-up, and analysis. Matrix spike samples
are analyzed to evaluate the effect of the sample matrix
on the accuracy of the analytical procedure.
Sample Duplicates are second
aliquots of client-supplied environmental samples that
are carried through every aspect of the procedure,
including preparation, clean-up, and analysis. Duplicate
samples are analyzed to evaluate the precision of the
analytical procedure. The relative percent difference
(RPD) between the two determinations is calculated and
compared to defined laboratory acceptance criteria.
Surrogate Compounds are organic compounds which are
similar to the analytes of interest in chemical behavior,
but which are not normally found in environmental
samples. Surrogates are added to samples to monitor the
effect of the specific sample matrix on the accuracy of
the analysis.
Instrument Calibration Procedures
Prior to the analysis of samples, standard calibration curves
of signal response versus analyte concentration are generated
on each analytical instrument that will be used for a
project. Standard calibration curves are generated by the
analysis of a series of standard solutions over a
concentration range appropriate for the samples to be
analyzed. The number and concentration of calibration
standards required is specific to the analytical methodology
employed.
GC/MS methodologies require that the GC/MS be tuned each
day prior to analysis of samples. The tuning compound
used for volatile organic analyses is
4-Bromofluorobenzene (BFB). The tuning compound used for
semivolatile organic analyses is
Decafluorotriphenylphosphine (DFTPP). No samples are
analyzed until the GC/MS has met the tuning criteria as
specified by the applicable method. Once tuning criteria
are met, the GC/MS is then calibrated for all target
compounds. Typically, a five point calibration curve is
used, depending on the specific methodology. On a daily
basis, continuing calibration is verified by using a
continuing calibration verification standard, which is
usually prepared at the midpoint of the multi-point
calibration curve. Typically, various System Performance
Check Compounds (SPCCs) are checked for a minimum average
relative response factor (RRF), and various Continuing
Calibration Compounds (CCCs) are checked for a maximum
relative percent difference between the RRF of the
multi-point calibration and the calibration verification.
Performance criteria for calibration, as defined in the
specific methodology, must be met prior to the analysis
of samples. Continuing calibration standards are prepared
from a source independent of the multi-point calibration
standard. Upon meeting all performance criteria,
typically samples must be analyzed within a 12 hour
period, after which the system performance
characteristics must be verified by re-tuning and
checking continuing calibration.
GCs are calibrated for all target compounds prior to the
analysis of samples. Typically, a five point calibration
curve is used, depending on the specific methodology. The
multi-point calibration curve is used to determine the
instrument's linear range, average response factors,
average retention time windows and average peak heights
or average peak area for all target compounds being
analyzed. On a daily basis, continuing calibration is
verified by using a calibration verification standard,
which is usually prepared at the midpoint of the
multi-point calibration curve. Continuing calibration
standards are prepared from a source independent of the
multi-point calibration standard. Performance criteria
for calibration, as defined in the specific methodology,
must be met prior to the analysis of samples. Typically,
a continuing calibration verification standard, which is
usually also a midpoint, is then analyzed at a frequency
of once every ten samples analyzed. The instrumental
sequence ends with the analysis of a continuing
calibration verification standard. Individual gas
chromatography methods may also have additional method
specific calibration verification requirements.
AAs are calibrated immediately prior to analysis
typically using a blank and four standards. The
calibration is then verified before, during and after
sample analysis using blanks and calibration verification
standards. Continuing calibration standards are analyzed
after every ten samples. Continuing calibration standards
are prepared from a source independent of the multi-point
calibration standard. Post-digestion analytical spikes
are performed on all client samples to monitor for matrix
effects.
ICPs are calibrated at least monthly using a blank and
two multi-element standards. The calibration is updated
daily prior to analysis using a blank and reslope
standard which is the same as the high standard used for
the monthly calibration. The calibration is verified
before, during and after sample analysis using blanks and
calibration verification standards. Continuing
calibration standards are analyzed after every ten
samples. Continuing calibration standards are prepared
from a source independent of the multi-point calibration
standard.
Data Reduction, Validation and Reporting
All analytical data generated are carefully checked for
accuracy and completeness. The data validation process, or
the process by which data are accepted or rejected, consists
of data generation, reduction, and three levels of review, as
described below.
The analyst who generates the analytical data has the
primary responsibility for the correctness and completeness
of the data. All data are generated and reduced following the
protocols specified by laboratory SOPs. Each analyst then
reviews the quality of his or her work based on an
established set of guidelines. The review step performed by
the analyst is designated the Initial Review.
Data is reviewed on the basis of a data package. Data
packages are comprised of the raw and reduced data for a
group of sample results for a specific methodology, and the
raw and reduced data for all of the associated preparation
batch quality control sample results and instrumental
calibration results.
Upon completion of the initial review, each data package is
reviewed by a Supervisor or Manager, whose function is to
provide an independent review of the data package. This
review is also conducted according to an established set of
guidelines. The review step performed by a Supervisor or
Manager is designated the Technical Review.
Upon completion of the Technical Review, each data package
is dissembled and individual sample results are assigned to
the appropriate project folder for reporting. After all of
the analytical requirements for a project are complete, a
project report is prepared for release to the client.
Prior to release of a project report to the client, the
Project Manager assigned to the project is responsible for
reviewing the report to ensure that the data meet the overall
objectives of the client, as understood by the Project
Manager. The review step performed by the Project Manager is
designated the Project Review.
Corrective Action Procedures
When non-conformances, deficiencies or errors occur, the
Quality Assurance Plan provides several systematic procedures
to address the discrepant situation. The two primary
systematic procedures employed are a Non-Conformance Report
and a Corrective Action Report.
An NCR is used to document sample conditions or
analytical conditions outside the recommended criteria of
the laboratory. For example, at time of sample receipt,
the Sample Management Department will use a Sample
Receiving Non-Conformance Report to document variances
from regulatory container, preservation and holding time
requirements, and to note all documentation errors or
omissions. The laboratory operations staff will use an
Analytical Non-Conformance Report to document all
analytical elements outside established criteria. For
example, unacceptable surrogate compound recoveries,
unacceptable laboratory control sample recoveries, and
unacceptable calibration check sample results must all be
documented by use of a Non-Conformance Report.
A CAR is used for all other discrepant situations, not
specific to samples or analytical elements with specified
criteria, that occur which require resolution in order to
maintain the proper functioning of the laboratory within
the guidelines established by the Quality Assurance Plan.
All Non-Conformance Reports and Corrective Action
Reports are forwarded to, reviewed by, and acted upon by
the appropriate Department Manager. All such reports are
then filed with, and reviewed by, and followed up by the
Quality Assurance Manager.
Performance and System Audits
Periodically, the Quality Assurance Officer conducts
performance audits and system audits of the laboratory to
ensure that personnel are adhering to the procedures set
forth in the Quality Assurance Plan. These audits may entail
observation of procedures as they are carried out, or a
review of records to demonstrate traceability and compliance
with all required documentation procedures. Reports of the
findings of these audits are made to management.
Standard Operating Procedures
All analytical methodologies are conducted according to
written Standard Operating Procedures (SOPs).
