Analytical Chemistry Flashcards
processes the provides basis for analytical measurement
Technique
a detailed set of instructions for a particular analysis using a specified technique
Method
A set of written instructions on how to apply a method to a particular sample
Procedure
Set of written guidelines for the analysis of a sample specified by an agency
Protocol
Component of interest in sample
Analyte
What are the instrumental methods of the following:
A. Absorption of radiation
B. Electrical Potential
C. Electrical Charge
D. Electrical current
E. Mass-to-Charge ratio
F. Rate of reaction
G. Thermal characteristics
H. Radioactivity
A. Spectroscopy
B. Potentiometry
C. Coulometry
D. Amperometry, Polarography
E. Mass Spectrometry
F. Kinetic methods
G. Thermal gravimetry, DTA, DSC
H. Activation and isotope dilution methods
Collection of all the components in the sample
Matrix
Process of collecting small amount of material whose composition represents the bulk of the material being sampled
Sampling
Portion of a solution subjected to analysis
Aliquot
A sample that contains all the components except the analyte
Blank
Experimental measurement that is proportional to analyte concentration
Signal
A. Middle result in the set of data. It is not affected by extreme values.
B. Also known as arithmetic mean. It is affected by extreme values.
A. Median
B. Mean
Indicates the reproducibility (repeatability) of a measurement.
Precision
Measure of the agreement between an experimental result and an expected value
Accuracy
Type of Errors
A. Causes date to be more scattered more or less symmetrically around the mean.
B. causes the mean of set data to differ from the accepted value.
C. Are often large, and may cause a result to be either high or low.
A. Random (indeterminate) error
B. Systematic (determinate) error
C. Gross error
Simple, widely used statistical test for deciding whether a suspected result should be retained or rejected
Q-test
Recommended by the ISO and the Americal Society for Testing and Materials in place of Q-test
Grubb’s test
Measure of the method’s ability to distinguish between two samples. It is reported as a change in signal per unit change in the amount of analyte
Calibration sensitivity
IUPAC defined it as the smallest concentration or absolute amount of analyte with a signal significantly larger than the signal from a suitable blank.
Limit of Detection (Detection limit)
Smallest amount of analyte that can be measured with reasonable accuracy
Limit of Quantitation (Quantitation Limit)
_______ of an analytical method is said to be specific if its signal depends only on the analyte
Specificity
Measure of method’s freedom from interferences
Selectivity
Magnitude of the background signal divided by the standard deviation of the background signal
Signal-to-Noise ratio
_____ is the fraction of the named material present
Purity