Quiz1

Question 1

Any instrumental analytical method is only as good as the ____ for the analyte of interest. To ascertain that an obtained analytical result is accurate on can use either an appropriate ____, compare the results from ____, or add a known amount of analyte to the sample and re-analyze it. The latter approach is referred to as ____.

Answer 1

calibration curve
standard ref. material
2 different anal. methods
standard addition

Question 2

‘Method specificity’ refers to the ability of an analytical method to distinguish the analyte (w.g. the API) from potential ____ (that might be present) which requires their ____ using an appropriate separation method.

Answer 2

impurities

baseline separation

Question 3

In the context of method validation, the ‘range’ refers to the concentration interval on the calibration curve over which the ____, the____ and the ____meet the specifications stipulated by a regulatory body (e.g. the FDA)

Answer 3

accuracy
precision
linearity

Question 4

The detection limit is defined as the smallest analyte concentration which is ____ from the ____. it is defined as the analyte concentration that produces a detector response that corresponds to the ____. There is only a ____% chance that a blank solution will produce a result> than the DL, which is also known as a ____.

Answer 4

statistically significant difference
blank
mean of blank +3S
~1%
false positive

Question 5

The analyte concentration corresponding to the limit of quantification (LOQ) is always higher that the detection limit (DL). True or False? Circle the correct answer.

Answer 5

True

Question 6

A change of the detector response to the analyte of interest by other compounds in the sample is referred to as a ____. To quantify the analyte in the sample of interest, we need to apply the standard addition method which involves the addition of increasing amounts of analyte to individual sample aliquots. It is important, however, to add a ____ of a standard solution to each sample aliquot so the sample matrix (in the obtained mixture) is ____ very much (-> matrix:analyte ratio = constant). One can then extrapolate the detector response if these measurements to determine the analyte concentration.

Answer 6

matrix effect
small volume
not diluted

Question 7

To maintain the analyte concentration between sampling and instrumental analysis one needs to prevent analye loss. This can be caused by processes such as ____, ____ ,and ____ (caused by microbes).

Answer 7

adsorption
volatilizaiton
analyte degradation

Question 8

The process of proving that an instrumental analytical method is acceptable for an intended purpose (e.g. to prove that the API concentration in a tablet is close to the desired value) is referred to as ____.

Answer 8

method validation

Question 9

The procedure by which an analye is chemically modified to facilitate its separation (from the matrix) and/or its quantification requires its chemical reaction with an appropriate reagent and is called ____.

Answer 9

derivatization

Question 10

In the context of trace/ultratrace analysis, list at least four possible ways how one can contaminate the sample of interest during sample collection/sample preparation and briefly describe what can be don to minimize/avoid contamination by each of these routes.

Answer 10

• mineral dust
• impurities, clean the containers before using them
• matrix effect, use clean supplies to avoid any contamination
  (- check all the equipments before using)