Analytical Detection Limit

Question 1

It is a combination of the bias and precision of an analytical procedure, which reflects the closeness of a measured value to a true value.

Answer 1

Accuracy

Question 2

It provides a measure of systematic, or determinative error in an analytical method. It is determined by assessing the percent recovery of spiked samples.

Answer 2

Bias

Question 3

It means concluding that a substance is present when it truly is not.

Answer 3

False Positive (Type 1 error)

Question 4

It means concluding that a substance is not present when it truly is.

Answer 4

False Negative (Type II error)

Question 5

It is the concentration equivalent to a signal, due to the analyte of interest, which is the smallest signal that can be distinguished from background noise by a particular instrument.

Answer 5

Instrument Detection Limit (IDL)

Question 6

It is the lowest concentration level that can be determined to be statistically different from a blank (99% confidence).

Answer 6

Limit of Detection (LOD) or detection limit,

Question 7

It is the level above which quantitative results may be obtained with a specified degree of confidence.

Answer 7

Limit of Quantitation (LOQ), or lower limit of quantitation (LOQ),

Question 8

It is the region of a calibration curve within
which a plot of the concentration of an analyte versus the response of that particular analyte remains linear and the correlation coefficient of the line is approximately 1 (0.995 for most analytes).

Answer 8

Linear Calibration Range (LCR), or Range of Linearity

Question 9

It is a numerical value expressing the maximum permissible level of a contaminant in water which is delivered to any user of a public water system.

Answer 9

Maximum Contaminant Level (MCL)

Question 10

It is the minimum concentration of a substance that can be measured and reported with 99% confidence that the analyte concentration is greater than zero.

Answer 10

Method Detection Limit (MDL)

Question 11

It is a quantitation limit that represents a practical and routinely achievable quantitation limit with a high degree of certainty (>99.9% confidence) in the results.

Answer 11

Practical Quantitation Limit (PQL)

Question 12

It is a measure of the random error associated with a series of repeated measurements of the same parameter within a sample. It describes the closeness with which multiple analyses of a given sample agree with each other and is sometimes referred to as reproducibility.

Answer 12

Precision

Question 13

It is an arbitrary number below which data is not reported.

Answer 13

Reporting Limit

Question 14

It defines the general physical-chemical makeup of a particular sample.

Answer 14

Sample Matrix, or Matrix

Question 15

It is a measure of the degree of agreement,
or precision, among replicate analyses of a sample.

Answer 15

Sample Standard Deviation, or Standard Deviation (s)

Question 16

It means the ability of a method or instrument to detect an analyte at a specified concentration.

Answer 16

Sensitivity

Question 17

It is a dimensionless measure of the relative strength of an analytical signal (S) to the average strength of the background instrumental noise (N) for a particular sample and is closely related to the detection level.

Answer 17

Signal to Noise Ratio (S/N)

Question 18

It is an observation or data point that appears to deviate markedly from other members of the population in which it occurs.

Answer 18

Statistical Outlier or Outlier