Chapter 5

Question 1

What we do to get the right answer

Answer 1

Quality assurance

Question 2

Known solutions of analyte that don’t involve the unknown solution

Answer 2

External standards

Question 3

Measurements

Answer 3

Raw data

Question 4

Concentrations derived from raw data by use of calibration methods

Answer 4

Treated data

Question 5

Quantities reported after statistical analysis of treated data

Answer 5

Results

Question 6

States purpose for which results will be used

Answer 6

Use objective

Question 7

Include sampling requirements, accuracy and precision, rate of false results, selectivity, sensitivity, acceptable blank values, recovery of fortification, calibration checks, and quality control samples

Answer 7

Specifications

Question 8

Says that the concentration exceeds the legal limit when, in fact, the concentration is below the limit

Answer 8

False positive

Question 9

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

Answer 9

False negative

Question 10

Being able to distinguish analyte from other species in the sample (avoiding interference)

Answer 10

Selectivity (specificity)

Question 11

The capability of responding reliably and measurably to changes in analyte concentration

Answer 11

Sensitivity

Question 12

A sample containing all components except analyte, and it is taken through all steps of the analytical procedure

Answer 12

Method blank

Question 13

Similar to method blank, but it has not been subjected to all sample preparation procedures

Answer 13

Reagent blank

Question 14

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

Answer 14

Field blank

Question 15

Refers to everything in the sample other than the analyte

Answer 15

Matrix

Question 16

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

Answer 16

Spike (fortification)

Question 17

Analyte solutions with known concentrations of analyte

Answer 17

Calibration check

Question 18

A quality control measure to help eliminate bias introduced by an analyst who knows the concentration of the calibration check sample

Answer 18

Performance test samples (quality control samples or blind samples)

Question 19

States what steps will be taken and how they will be carried out

Answer 19

Standard operating procedures

Question 20

The process of (1) collecting data to show that analytical procedures are operating within specified limits and (2) verifying that final results meet use objectives

Answer 20

Assessment

Question 21

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

Answer 21

Method validation

Question 22

Measures how well a calibration curve follows a straight line, showing that response is proportional to the quantity of analyte

Answer 22

Linearity

Question 23

Nearness to the truth

Answer 23

Accuracy

Question 24

How well replicate measurements agree with one another

Answer 24

Precision

Question 25

Describes how well one person can obtain the same results when analyzing the same sample by the same procedure with the same equipment in the same laboratory

Answer 25

Repeatability

Question 26

Describes how well different people in different laboratories with different equipment can get the same results when analyzing similar samples by the same procedure

Answer 26

Reproducibility

Question 27

Concentration range over which calibration curve is linear

Answer 27

Linear range

Question 28

Concentration range over which there is measurable response

Answer 28

Dynamic range

Question 29

Concentration range over which linearity, accuracy, and precision meet specifications for analytical method

Answer 29

Range

Question 30

The concentration of analyte that gives a signal to three times the standard deviation of signal from a blank

Answer 30

Detection limit

Question 31

The concentration below which regulations say that a given analyte is reported as “not detected”, which doesn’t mean that analyte is not observed

Answer 31

Reporting limit

Question 32

The ability of an analytical method to be unaffected by small, deliberate changes in operating parameters

Answer 32

Robustness

Question 33

A change in the analytical signal caused by anything in the sample other than analyte

Answer 33

Matrix effect

Question 34

Standard deviation of the mean

Answer 34

Standard uncertainty

Question 35

Added standard is the same substance as analyte

Answer 35

Standard addition

Question 36

Added standard is different from analyte

Answer 36

Internal standard

Question 37

Solutions with known concentrations of analyte are used to prepare a calibration curve

Answer 37

External standard