Chapter 3 Flashcards
GLP
Good laboratory practice
ISO
International Organization for Standardization
ANSI
American National Standards Institute
ASQ
American Society of Quality
VIM
International Vocabulary of Basic and General Terms in Metrology
IUPAC
International Union of Pure and Applied Chemistry
OIML
International Organization of Legal Metrology
AOAC
The Association of Analytical Communities
CITAC
Cooperation on International Traceability in Analytical Chemistry
SOFT
Society of Forensic Toxicology
NIST
National Institute of Standards and Technology
AAFS
American Academy of Forensic Sciences
SWGDRUG
Scientific Working Group for Seized Drug Analysis
SWGMAT
Scientific Working Group for Materials Analysis
ASTM International
American Society for Testing and Materials International
ASCLD/LAB
American Society of Crime Laboratory Directors, Laboratory Accreditation Board
FQSI
Forensic Quality Service International
ABC
American Board of Criminalistics
SOP
Standard operating procedure
SRMs
Standard reference materials
CRMs
Certified standard reference materials
The process of reviewing a forensic laboratory against a set of accepted standards such as promulgated by ASCLD/LAB or ISO to insure that its policies, procedures, and practices meet these standards. If so, the laboratory is said to be accredited
Accreditation
How close the calculated value to the true or accepted value; includes components of trueness and bias
Accuracy
A group of samples and related QC samples
Batch
The difference between an experimentally determined value and an accepted true value; quantitative expression of trueness
Bias
A sample that contains no analyte of interest
Blank
QC samples provided to the analysis without a known value
Blind samples
The process of establishing a link between the output of an instrument or equipment and sample concentration
Calibration
A sample prepared independently of the calibration curve and used to detect problems with the curve
Calibration check sample
A plot and mathematical relationship (usually linear) between the concentration of an analyte and an instrument response
Calibration curve
The process of insuring that a forensic practitioner is competent to conduct analyses based on written and laboratory testing
Certification
A cradle-to-grave document that tracks evidence
Chain of custody
A running record of the performance of a device or solution that identifies when performance is no longer within accepted uncertainty ranges
Control chart
A value calculated to gauge the goodness of fit of points to a line generated by a linear regression algorithm
Correlation coefficient
A variable that has a value derived from or dependent on the value of another
Dependent variable
Separate samples taken from the same source; not the result of subdividing one sample
Duplicates
A calibration curve in which the standards are made in simple solvents that may not match the matrix
External standard curve
Terms used to describe the performance of a validated analytical method
Figures of merit
A criteria used to gauge the utility of a given method to answer the forensic question and to provide the pertinent data in the most expedient and reliable way
Fitness for purpose
A variable with a value that doesn’t depend on or derive from any other variables
Independent variable
A calibration method that involves addition of internal standards to all samples and standards and to which concentrations and responses are ratioed
Internal standard curve
Samples with known accepted values
Knowns
A fit of a line or other curve to a set of points that is optimized by minimizing the total difference of all points to the curve. Distances are squared to eliminate potential canceling with some (+) and others (-) relative to the curve
Least-squares regression
The lowest signal, or the lowest corresponding quality to be determined from the signal, that can be observed with a sufficient degree of confidence or statistical evidence
Limit of detection (LOD)
The smallest amount or the lowest concentration of a substance that is possible to be determined by means of a given analytical procedure with the established accuracy, precision, and uncertainty
Limit of quantification (LDR)
The process of creating a straight line and linear equation to describe the relationship between a dependent and independent variable
Linear regression
The situation that arises when the solvent system used to generate a calibration curve doesn’t match the matrix of the sample
Matrix mismatch
A sample that should produce a negative or no reaction or response in analytical procedure; part of QA and QC
Negative control
A sample that should produce a positive reaction or response in an analytical procedure; part of QA and QC
Positive control
Reproducibility of replicate measurements
Precision
The philosophy and practices used to insure the goodness and reliability of data
Quality assurance (QA)
Procedures used as part of quality assurance
Quality control (QC)
A line describing points that have a linear relationship or correlation
Regression line
Closeness of the agreement between the results of successive measurements of the same measurand under similar and controlled conditions
Repeatability
Repeat measurements of the same criteria under similar conditions; multiple samples derived from one larger sample
Replicates
Closeness of the agreement between the results of measurements of the same measurand under controlled conditions; typically broader than repeatability
Reproducibility
Analytes purposely added to a sample to gauge recovery and flag potential matrix problems and affects
Spike
A calibration method which uses the sample as the matrix and to which increasing aliquots of the standard analyte are added
Standard addition
A cradle-to-grave approach to quality assurance that integrates all aspects inside and outside of a particular organization or lab
Total quality management (TQM)
The ability to relate a measurement or piece of equipment to an unassailable standard
Traceability
