lab

 

If you want to prove to the community that the methodology you are reporting is accurate and reliable providing information on method validation is required.  The metadata in this category needs to be open such that the wide range of validation methods can be reported. After thinking about his for a few months the reporting of metrics, statistics, validation processes, or example data (added 02-17-15) is all about making a statement of the quality of the methodology - how good is the method at performing the analysis.  So, the category has been renamed quality metadata (02-17-15). Please let This email address is being protected from spambots. You need JavaScript enabled to view it. know if you have any comments, or additions to the list below.

Metrics

Numeric values that are characteristic of the chemical analysis method

  • Coefficient of Determination (R-squared)
  • Confidence Interval [added 02-17-15]
  • Detection Limit - From Blank Analysis
  • Detection Limit - From Calibration
  • Limit of Quantitation
  • Limit of Linearity
  • Linear Dynamic Range
  • Linear Regression Equation
  • Repeatability (Intra-assay precision)
  • Sensitivity (Slope of the Calibration Curve)
  • Sample Throughput
  • Signal-to-noise ratio (at a specific analyte concentration) [added 02-26-15]
  • Specificity/Selectivity [updated 02-26-15]
  • Stability (remove 02-26-15]

Statistics Chemometrics

Statistical tests that evaluate the appropriateness of the model used in the calibration of data or comparison of chemical analysis metrics between different analysis methods

  • F-test
  • Paired t-test
  • One-way ANOVA
  • Two-way ANOVA
  • Non-parametric Test

Validation

Processes that are carried out to measure accuracy, assess reliability over time or across laboratories

  • Quality Assurance (QA)
  • Quality Control (QC)
  • Statistical Process Control (Control Charts) [moved 02-26-15]
  • SRM/CRM Analysis
  • Sample Spike Recovery
  • Method Blank Analysis (different than the analysis blank)
  • Single Laboratory Validation (Intermediate Precision)
  • Inter-laboratory Validation (Reproducibility) OR Ruggedness

Example Data

  • Chromatogram
  • Peak Table
  • Spectrum
  • Calibration Curve

Thinking about this category of metadata it seems to make sense to provide enough items so that a clear picture of the instrumental setup and configuration can be recorded.  Others looking at an analysis are mostly interested in being able to reproduce it and the more information they have the easier that will be.

  • instrument: the general type of instrument being used to the analysis (vocabulary) [10-12-14]
  • hyphenated instrument: the general type of hypenated instrument (e.g. GC-MS) being used to perform the analysis (string) [04-29-15]
  • apparatus: non-instrumental equipment used to do an analysis (string) (e.g. 50 mL burette, sintered glass crucible, etc.) [10-12-14]
  • manufacturer: the name of the manufacturer of the instrument being used (string) [03-01-15]
  • model number: the manufacturers model number used to identify the instrument (string) [03-01-15]
  • serial number: the serial number of the instrument (string) [03-01-15]
  • software name: name of the software used to run the instrument (plus any additional components) (string) [10-12-14]
  • software version: version of the software used to run the instrument (string) [10-12-14]
  • operating system: the operating system used to run the instrument software (including version #) (string) [10-12-14]
  • accessories: a list of any accessories installed onto the main instrument (e.g. autosampler, fraction collector, etc.) (string) [10-12-14]
  • configuration: a textual description of the (physical) configuration of the instrument, used to highlight any unique/interesting aspects of the system (string) [10-12-14]
  • settings: a textual list of the values used for important instrumental parameters (string) [10-12-14]

While a daunting task to begin with, coming up with the different analytical techniques for chemical analysis is not as bad as it could be.  There are plenty of textbooks to look at and the IUPAC Analytical Division has done a great job with the Orange Book (see below).  There are also a few of other websites listed below that have a lot of information to help organize this information.

Technique Categories

  • Chromatographic
  • Electrochemical
  • Microscopic
  • Spectrometric
  • Spectroscopic
  • Other Methods
    • Elemental Analysis
    • Enthalpimetry
    • Flow Methods
    • Immunoassay
    • Kinetic Methods
    • Microplate Assays
    • Other Seapration Methods
    • Radiochemical Methods
    • Surface Methods
    • Wet Chemical Methods

Currently, there is a first draft of the vocabulary available as an Excel file. Two guiding principles will be used in the vocabulary development. Firstly, this is for chemical analysis and thus does not extend to physical property testing. Second, it is not practical to try and capture each individual technqiue variant as there are an infinite number.  Instead we classify them in groups.

If you think there is a category or technique missing let This email address is being protected from spambots. You need JavaScript enabled to view it. know.

References

This sample matrix vocabulary is under active development. Currently a first draft is available as an Excel file. Main categories are shown below.

  • Agricultural
  • Biologics
  • Chemicals (including metals, alloys, and materials)
  • Commercial Products
  • Environmental (including Geological)
  • Food/Beverage
  • Miscellaneous (needed?)
  • Petrochemicals
  • Pharmaceuticals
  • Reference Materials
  • Wastes (including hazardous wastes)

The current draft has the agricultural classes of materials identified and linked to other database and domain terminologies and ontologies.  This will be done done for the other main groups as domain experts provided feedback about completeness.

If you have any suggestions about vocabulary terms or main categories please contact This email address is being protected from spambots. You need JavaScript enabled to view it..

History

  • 10-03-2014: Initial list of main categories added.
  • 12-08-2014: List of categories revised.  First draft Excel file added.