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Quality Assurance

The objective of Maryland Spectral Services is to provide analytical data that are valid and defensible and that meet the user's needs. Key to the achievement of this objective is MSS's Quality Assurance/Quality Control (QA/QC) program, which is overseen by our QA Officer. The QA/QC program provides a strict system that manages sample custody, sample analysis, instrument calibration and maintenance, and data management.

Sample Custody

All samples received by MSS are immediately compared to the accompanying chain-of-custody (COC) form and any discrepancies are noted. Notations are made which describe the sample condition when received. The CoC is signed to record the transfer of custody. Each sample is logged into the MSS Sample Logbook and assigned a unique, sequential laboratory number, which is used to track the sample through the laboratory. Samples are stored according to accepted U.S. EPA protocols. Access to the premises is strictly controlled by locked doors or visual monitoring.

Sample Analysis

Samples are analyzed following U.S. EPA methods or, where appropriate, methods that have been developed or customized based on client-specific needs. Data quality is evaluated by the analysis of quality control samples, the types and frequencies of which are determined by client requirements. Method blanks are analyzed and reported for every analytical batch. The recoveries of surrogate spikes are reported for every sample analysis, where applicable.

Instrument Calibration and Maintenance

The analytical instruments are calibrated according the frequency and other requirements of the method being used. No sample analyses are performed until the initial and continuing calibration criteria have been met. All standard preparations and other calibration activities are rigorously documented. Preventative maintenance is scheduled according to manufacturer’s recommendations. Maintenance is provided by trained employees and by manufacturer’s service personnel. All preventative and non-routine maintenance is recorded in logbooks provided with each instrument.

Data Management

All sample records are maintained in an organized manner so that for each analysis all records (e.g., chain-of-custody forms, tuning criteria, initial multilevel calibration, on-going calibrations, field and QC sample results, final report) are readily available for retrieval and inspection. Current records are kept in the central files; older records are placed in indexed archive boxes and stored in a secure location. All paper records are maintained for at least five years and computer tapes for two years.