QA vs QC

Question 1

Quality Assurance

Answer 1

• encompasses a set of procedures designed to ensure the reliability of laboratory analysis
• process-oriented and focuses on defect prevention

Question 2

Quality Control

Answer 2

• encompasses a set of procedures designed to
  validate measurement quality
• product oriented and focuses on defect identification

Question 3

Raw data

Answer 3

individual values of a measured
quantity

Question 4

Treated data

Answer 4

concentrations found by
applying a calibration procedure to the raw data

Question 5

Results

Answer 5

what is ultimately report such as
mean, standard deviation and confidence interval after applying statistics to treated data

Question 6

True or false: QA begins with sampling

Answer 6

true

Question 7

False positive

Answer 7

says that the concentration
exceeds the legal limit when in fact the concentration is below the limit

Question 8

False negative

Answer 8

says that the concentration is
below the limit when it is actually above the limit

Question 9

Method blank

Answer 9

sample containing all components
except analyte

Question 10

Reagent blank

Answer 10

similar to method blank but it has not
been subjected to all sample preparation procedure

Question 11

Field blank

Answer 11

similar to method blank but it has been
exposed to the site of sampling

Question 12

Calibration blank

Answer 12

used in establishing the analytical
curve

Question 13

Rinse blank

Answer 13

is used to flush the instrument uptake
system and nebulizer between standards, check
solutions and samples to reduce memory
interferences

Question 14

Matrix

Answer 14

refer to everything else in the sample
other than analyte

Question 15

Spike (fortification)

Answer 15

known quantity of analyte
added to a sample to test whether the
response to a sample is the same as that
expected from a calibration curve.

Question 16

Performance test samples

Answer 16

quality control
measure to help eliminate bias introduced by
the analyst knowing the concentration of the
calibration check sample

Question 17

Standard Operating Procedures

Answer 17

states what
steps will be taken and how they will be carried
out are the bulwark of quality assurance

Question 18

Assessment

Answer 18

process of collecting data to show that
analytical procedures are operating
within specified limits and verifying that
final results meet use objectives

Question 19

Method Validation

Answer 19

process of proving that an analytical method is
acceptable for its intended purpose

Question 20

Repeatability (spread of measurements

Answer 20

established
through the standard deviation and/or the relative
standard deviation

Question 21

Ruggedness

Answer 21

ssessment of precision or variation
by different analysts using different instruments on
different days but within the same laboratory

Question 22

Reproducibility

Answer 22

refers to the variation obtained by
different analysts utilizing different instruments in
different laboratories using the same analytical
method with similar samples (Precision)

Question 23

Selectivity

Answer 23

ability of a method to distinguish the
response of different analytes from each other
means being able to distinguish analyte from other species in
the sample (avoiding interference)

Question 24

Specificity

Answer 24

ability of a method to provide a response
to a single analyte only
ability of an analytical method to distinguish the analyte from
everything else that might be in the sample

Question 25

Linearity

Answer 25

measures how well a calibration curve follows a straight line

Question 26

Sensitivity

Answer 26

capability of responding reliably and measurably to changes in analyte concentration

Question 27

Accuracy

Answer 27

nearness to the truth

Question 28

spiking

Answer 28

most common method to evaluate accuracy

Question 28

Range

Answer 28

concentration interval over which linearity, accuracy and precision are all acceptable (linear vs dynamic)

Question 28

Limit of Quantitation

Answer 28

smallest amount that can be measured with reasonable accuracy

Question 29

Limit of Detection

Answer 29

smallest quantity of analyte that is “significantly different” from the blank

Question 30

Robustness

Answer 30

measure of the capability of an analytical method to remain unaffected by small (but intentional) changes to parameters in the method

Question 31

Recovery

Answer 31

the fraction of analyte added to a blank matrix before analysis that is actually measured by the method

Question 32

Matrix effect

Answer 32

change in the analytical signal caused by anything in the samples other than analyte

Question 33

Internal Standard

Answer 33

Known amount of a compound different from analyte that is added to the unknown