UNDERSTANDING ENVIRONMENTAL LABORATORY/QC REPORTS Maya Murshak - PowerPoint PPT Presentation
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UNDERSTANDING ENVIRONMENTAL LABORATORY/QC REPORTS Maya Murshak
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Title: UNDERSTANDING ENVIRONMENTAL LABORATORY/QC REPORTS Maya Murshak
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UNDERSTANDING ENVIRONMENTAL LABORATORY/QC
REPORTSMaya Murshak Merit Laboratories, Inc.
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Why are we having this class?
- Understand a Level I report.
- Analytical results
- Define quality in the laboratory and how it is
represented in a Level II report. - Batch quality control summary
- Influences of sampling on final results
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What is Quality?
- Quality Assurance
- Defined as everything done with respect to
producing reliable data. - Quality Control
- Defined as a single step or procedure to evaluate
a process or test
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Why Quality?
- Recognize, quantitate, and minimize errors.
- Describe the accuracy and precision of the data.
- Assess the legality of the reported results,
i.e., defensible in the US court of law.
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Certifications, Audits and PE Programs
- Certifications at the federal, state and client
level. - Most certifications have audits
- Most certifications have PE samples
- Double blind samples that we analyzed without
knowing the answers. - Bi-annual PE samples.
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NELAP
- National Environmental Laboratory Accreditation
Program - Non government program sponsored by individual
states and the EPA. - On site audit every 2 years
- Bi-annual PE studies
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Quality starts with field sampling
- A majority of all errors in environmental
analysis result from incorrect sampling. - Factors
- Safety
- Obtaining a representative sample
- Preventing contamination
- Legal documentation
- Protecting the sample from changing prior to
analysis (preservation) - Detailed standard operating procedures
- Typically not covered by audits or PE programs.
- Detailed record keeping
- Field records
- Chain of Custody
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Field Quality Control
- Field blanks
- Trip blanks
- Equipment blanks
- Preservatives
- Ice
- Bottles
- Chemicals
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Custody
- Important to document where and who has the
sample at all times. - Chain of Custody - Legal document
- Description of the sample
- Who collected, what container, where and when.
- Requested tests
- Signature and dates/times when the sample was
passed from person to person - Included with the final report.
- Internal Custody
- Often provided by LIMS system
- Custody of each bottle NELAC regulation
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Laboratory Quality Control
- Quality Control designed to check four general
areas. - Calibration of instrument
- Process is contamination free
- Process is efficient and accurate
- Matrix effects
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GM Level I Report
- Sample information
- Parameter details
- Custody documents
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Example Report
Sample Information
Parameter Details
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Sample Information
- Project ID
- Sample ID
- Field Personnel
- Date Time collected
- Date time Received
- Laboratory ID
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Correct Methods
- Correct method depends on regulatory program
- NPDES/IPP - 40 CFR 136
- Waste/RCRA - SW-846
- Monitoring/Landfill - SW-846 or 40 CFR 136
- Drinking Water
- Alternate Test Procedures
- NPDES/IPP
- Parameters not listed in 40 CFR 136
- Michigan in EPA Region 5
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DETECTION LIMITS
- MDL - Method Detection Limit
- The minimum level of an analyte that can be
qualitatively identified with 99 confidence. (40
CFR Part 136, Appendix B) - Reporting Limits
- The minimum level of an analyte that can be
reasonably reported by the laboratory taking into
consideration the sample matrix. - PQL, LOQ
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QC ORGANIZATION - BATCHES
- Sample and QC data are grouped into batches
- A batch may be defined by sample count (e.g. 20)
- A batch may be defined by time elapsed (e.g. 12
hr.) - Each batch has QC validating its samples
- Example LCS, Blank, MS, MSD, Duplicate
- Types of batches
- Preparation (e.g. digestion, extraction)
- Analytical (e.g. GC/MS, ICP/MS)
- Samples may belong to both types of batches
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EVALUATING QC - LEVEL II DATA
- Evaluate Preparation QC Items (as analyzed)
- Method Blank
- Laboratory Control Sample (LCS)
- Matrix Spike (MS)
- Duplicate and/or Matrix Spike Duplicate (Dup,
MSD) - Surrogates (for organic analyses)
- Instrument QC Items are not included
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SUMMARY OF QC INFLUENCES
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EXAMPLE - MATRIX INTERFERENCE
- Actual sample matrices may contain target and
non-target interferences that preclude the
analysis of a sample in an undiluted state and
result in elevated reporting limits.
PNAs above calibration range
Heavy Oil causing poor internal standard recovery
Method Blank
Sample Exhibiting Interference
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COURSE CONCLUSIONS
- Different QC items are designed to characterize
the various cumulative effects contributing to
data quality - The requested QC deliverable affects the scope
and detail of QC items provided and - The sample matrix can often play a large role in
the usefulness of the analytical results for
their intended purpose.
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ABOUT THE PRESENTER
- Maya Murshak
- Maya is the Quality Assurance and Technical
Director for Merit Laboratories, Inc. and has
been with the lab since it was started in 1987.
She currently works primarily with laboratory
certification, accreditation, data validation and
project coordination. She also has over 15 years
of practical laboratory experience based on her
extensive analytical work with both GC and GC/MS
systems. Maya is a Chemical Engineer, holding
both B.S. and M.S. degrees from Michigan State
University.
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Thank You
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