Raw Data Checking

The initial phase of data checking consists of simple and obvious procedures that need to be carried out as the first stage of acceptance of the results from the laboratory. This needs to be done systematically and as soon after the results are received as is possible. The original digital file of results as received from the laboratory should always be archived unchanged and the subsequent modifications described in the following sections performed on a copy of the original data file. 

Dealing with missing, semi-quantitative and unreliable data 

The low-detection limits as reported by analysts are generally more conservative than are the actual limits. This is suggested by the slope of the curve on the data 

Historically, the G-BASE project has replaced values recorded as detection by a value one half the detection limit for soils and stream sediments and for consistency with older data. This practice continues. There is no sound basis for such a remedy 

Current procedures emphasise the importance of storing the laboratory recorded data ( raw data ) and the XRFS analyses are now direcdy transferred via a Laboratory Information Management System (LIMS) to data tables in the BGS corporate geochemistry database. Conditioned data is loaded to different data tables and importantly every analyte result has an accompanying qualifier field that can be provided to the user to explain any data quality issues. 

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The Drug Organization is responsible for consultation on drug development, raw data check, GLP/GCP/GPMSP inspections and reviews on equivalency. 

Raw data are repeatedly corrected by an amount determined by a correcting algorithm and checked against the constraints they must satisfy. The residuals of the constraints, which is a measure of the degree to which the constraints ate not redefined, are calculated and the algorithm attempts to rninirnize these residuals. The procedure is continued until the residuals can no longer be reduced. 

Using the raw data in Fig. 3.20, we can identify the Pareto-optimal set for the HER activify/stabilify criteria. This set represents the best possible compromise between activity and stability criteria for the surface alloys that we have considered the alloys in the set are, thus, logical choices for further consideration. The presence of pure Pt on the Pareto-optimal set is, in effect, a sanity check for our computational screening procedure. Pt is well known to be the most active and stable pure metal for the HER in acidic conditions. The alloys seen on the Pareto-optimal set include RhRe and BiPt. 

Interestingly, the correct polarity of the Mossbauer drive can be checked by using the isomer shift of oc-iron with respect to the materials in Table 3.1. After folding of the raw data, the center of the calibration spectrum without further correction must be at —0.12 mm s relative to the Co/Rh source material. 

Any validation and verification work performed must always be documented in such a way that the results can be checked and the scope of a method is clear. International standards, e.g., ISO 17025, contain separate sections regarding documentation, which should be observed. The NMKL procedure on method validation states that It is of particular importance that the report includes all raw data from the experimental work, or references to where such data can be found . In some circumstances this complete documentation is impractical. Even where it is practical, it is usually impossible to publish these results together with the methods. 

In electronic data packages used in held studies, there are some electronic data that are directly entered by the held investigator (FI) and some that are generated by the program (e.g., dates and times). Both types of raw data need to be verified by QA personnel, who should check not only directly entered data, but also computer-entered data. In order to conduct a thorough data audit, QA should determine which data are direct entry and which are automatic. 

QA should ensure that notes and various descriptions (e.g., sampling method, test system observations, etc.) are clear and thorough during the raw data audit. In addition, all audit trails should be checked for clarity and to ensure that each... 

With electronic notebook studies, there will also be paper data to audit. This will include facility data (e.g., weather data, equipment maintenance records, storage temperature logs, personnel records, etc.) and study specific documents, such as faxes, e-mails, paper notes, etc. When paper data have been transcribed into the electronic notebook, they should be checked by QA to ensure accuracy. Any data that have been transcribed for whatever reason must be identified as such with the original raw data attached to them. QA should ensure that all paper data have adequate identification (e.g., study and trial numbers), that they are recorded per GLP, including dated signatures, and that all of the pertinent paper data or exact copies are sent to the Study Director for archiving. 

Raw data from SPMD exposures should include target compound levels in the various blanks, and the amounts found in exposed SPMDs in ng per sample. When the triolein phase is separately analyzed, the raw data should include the amounts in the LDPE phase as well. When PRCs are used, the measured t = 0 levels and the calculated spike levels should be included as an additional check on PRC recovery. 

A laboratory that conducts nonchnical laboratory studies must provide space for the storage of raw data and specimens from such studies. Access to the archives must be controlled. This is best accomphshed by providing a lockable area and by defining in the laboratory s SOPs who has access to archive materials and under what conditions (e.g., use only within the archives or check-out rights). 

There was an instance in which a laboratory that had conducted a number of studies for EPA regulatory purposes went out of business and the records relating to studies the laboratory had conducted were lost. In this case EPA required many of the studies to be repeated. The lesson to be learned from this experience is that a sponsor should be very careful in the selection of contract facilities and should periodically check with the contract lab to ensure that the laboratory continues to operate and that study records continue to be maintained. Some sponsors obtain the specimens and/or originals or copies of aU raw data for contracted studies for storage in their own archives to protect against the loss of raw data at the contract laboratory. 

Together, raw data and results from calibration checks, spike recoveries, quality control samples, and blanks are used to gauge accuracy. Analytical performance on replicate samples and replicate portions of the same sample measures precision. Fortification also helps ensure that qualitative identification of analyte is correct. If you spike the unknown in Figure 0-5 with extra caffeine and the area of a chromatographic peak not thought to be caffeine increases, then you have misidentified the caffeine peak. 

These studies are to be regarded as experiments which probe time-correlation functions. They provide the raw data against which various dynamical theories of the liquid state can be checked. These studies provide insight into the microscopic dynamical behavior of real diatomic liquids for both the experimentalist and theoretician alike. 

The GLP regulations boil down to this if you submit a study to a regulatory agency, then this study should have been conducted in a proper facility by qualified personnel, using properly maintained and calibrated equipment, following written standard procedures and checked routinely by an independent and qualified person. All the original data should be archived and it should be possible to validate the final report of the study by an audit of raw data. 

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