mod 1 Flashcards
The closeness of an experimental measurementer result to the true or accepted value.
Accuracy
Constituent of the sample which is to be studied by quantitative measurements of identified qualitatively.
Analyte
A highly accurate defermination, usually of a valuable constituent in a material of large bulk, e.g. minerals and ores. Also used in the assessment of the purity of a material, e.g. the physiologically active constituent of a pharmaceutical product.
Assay
That proportion of a measurement which arises from sources other than the analyte itself. Individual contributions from instrumental sources, added reagents and the matrix can, if desired, be evaluated separately.
Background
A measurement or observation in which the sample is replaced by a simulated matrix the conditions otherwise being identical to those under which a sample would be analyzed.
Blank
A solution that has no analyte
Blank
A procedure which enables the response of an instrument to be related to the mass, volume or concentration of an analyte in a sample by first measuring the response from a sample of known composition or from a known amount of the analyte,
Calibration
Process of configuring an instrument to provide result for a sample within acceptable range
Calibration
The amount of a substance present in a given mass or volume of another substance.
concentration
A component of a sample
Constituent
how many is major constituent?
> 10%
how many is minor constituent
0.01-10%
how many is trace constituent?
1-100 ppm (0.0001-0.01%)
how many is ultratrace constituent?
< 1ppm
The smallest amount or concentration of an analyte that can be detected by a given procedure and with a given degree of confidence.
Detection Limit
A quantitative measure of an analyte with an accuracy of considerably better than 10% of the amount present.
Determination
That amount of a substance which, in a specified chemical reaction, produces, reacts with or can be indirectly equated with one mole
Equivalent
What is the value of one mole?
6.022 x 10 ^ 23
A semi-quantitative measure of the amount of an analyte present in a sample, i.e. an approximate measurement having an accuracy no better than about 10% of the amount present.
Estimation
What are the 2 parameters of quality control?
Sensitivity and Specificity
It is the ability of an analytical method to measure the smallest concentration of an analyte of interest
Sensitivity
The ability to test only the analyte of interest.
Specificity
An effect which alters or obscures the behavior of an analyte in an analytical procedure.
Interference
A compound or element added to all calibration standards and samples in a constant known amount
Internal Standard
Treatment of a sample with a reagent to prevent interference with the response of the analyte by other constituents of the sample
Masking
The remainder of the sample of which the analyte forms a part.
Matrix
The overall description of the instructions for a particular analysis
Method
The random or indeterminate error associated with a measurement or result.
Precision
Other names for Precision
Variability and Reproducibility
A substance whose purity and stability are particularly well established and with which other standards may be compared.
Primary Standard
A description of the practical steps involved in an analysis
Procedure
A chemical used to produce a specified reaction in relation to an analytical procedure
Reagent
A substance or portion of a substance about which analytical information is required
Sample
The change in the response from an analyte relative to a small variation in the amount being determined
Sensitivity
The ability of a method to facilitate the detection or determination of an analyte.
Sensitivity
A pure substance which reacts in a quantitative and known stoichiometric manner with the analyte or a reagent
Standard
The pure analyte or a substance containing an accurately known amount of it which is measured before and after adding a known amount of that analyte to the sample
Standard
A method of quantitative analysis whereby the response from an analyte is measured before and after adding a known amount of that analyte to the sample
Standard addition
Determinantion of that concetration of an analyte or reagent solution from its reaction with a standard or primary
standard
Standardization
The principle upon which a group of methods is based
Technique
In order to ensure that results yielded by a method are as accurate as possible, it is essential to __________ by analyzing standards which have an accepted analyte content and a matrix similar to that of the sample.
Validation of Methods
In order to ensure that results yielded by a method are as accurate as possible, it is essential to __________ by analyzing standards which have an accepted analyte content and a matrix similar to that of the sample.
Validation of Methods
It is often called the central science
Chemistry
It is a measurement science consisting of a set of powerful idead and methods that are useful in all fields of science, engineering and medicine.
Analytical Chemistry
What are the 3 disciplines that are required in an analysis?
Qualitative analysis, Quantitative analysis, and analytes
This reveals the identity of the constituents (elements and compounds) in a sample.
Qualitative analysis
Indicates the amount of each substance in a sample
Quantitative analysis
The components of a sample that are determined either through qualitative or quantitative analysis
Analytes
What are the functions of Analytical Chemistry?
Fundamental Research, Product Developmet, Product Quality Control, Monitoring and Control of Pollutants, Assay and Medical and Clinical Studies
The first steps in unravelling the details of an unknown system frequently involve the identification of its constituents by qualitative chemical analysis
Fundamental Research
This aims to improve theories
Fundamental Research
What will happen when quality control is not present?
Damaged products will be released
What are the different steps in Analysis?
Identify the Problem, Choice of Method, Sampling, Prelimenary Sample Treatment, Separations, Final Measurement, Method Validation, Assessment of Results
This is a vital step in the solution of an analytical problem
Choice of Method
What is the first step for analysis?
Identify the Problem
This is the cornerstone of reliable analysis
Correct Sampling
What is an example of preliminary sample treatment
Masking
This step is often the quickest and easiest of the seven but can only be as reliable as the preceding stages
Final Measurement
Collection of all of the components in the sample containing an analyte
matrix or sample matrix
Techniques or reactions that work for only one analyte
Specific
techniques or reactions that apply to only a few analytes
Selective
process of determining the proportionality between analyte concentration and a measured quantity
calibration
Steps sa table ng analysis
Select method, Acquire sample, process sample, Measurable property eliminate interference, measure property, calculate result, estimate reliability of results
3 methods of preliminary treatment
preparation of laboratory sample, replicate laboratory sample, prepare solutions for sample
