Terms Flashcards
measure response of the analytical procedure to impurities or interfering species in the re
blanks
arise from color of starting reagent, reaction of impurities, & reactions of interfering species
absorbance
shows response of an analytical method to known quantities of analyte
calibration curve
contains unknown [analyte]
standard solution
contains all reagents and solvents used in the analysis, but no added analyte.
blank solution
[analyte] range over which response is proportional to the
concentration
linear range
concentration range over which there is a measurable response to analyte.
dynamic range
smallest quantity of analyte that is ‘statistically’ different from the blank
detection limit
equals .051au
ppm
measuring length with a ruler
direct measurement
when we calibrate an instrument and then measure the sample
indirect measurement
a mistake, may be able to remove from consideration via statistical analysis.
gross error
a permanent deviation from the true result. the method is flawed or instrumental bias. always gets the wrong result mostly always the instrument.
systematic error
repeating experiments gives a slightly different answer inability for scientists to recreate the exact environment
random error
getting the right answer with acceptable uncertainty
accuracy
getting the same answer each time you take the measurement
precision
also known as the coefficient of variation, a measurement expressed as a fraction or a %age
relative standard
deviation
defined to express the confidence as the mean draws closer to ¼. becomes smaller as the number of data increases
standard deviation of the mean
estimate of the range within which the true value might fall within a given probability
Confidence interval
the limits of the confidence interval
confidence limit
evaluates the differences between the spread based on their s.d. - defined in terms of the variances in data
f test
evaluates statistical differences between the results - whether or not they measure the same thing.
T-test
used to obtain an improved estimate of the precision of a method and calculate the precision of the two sets of data
in a paired t test
pooled standard deviation
accurately weighed quantity of highly pure material.
primary standard
if the material is not sufficiently pure, a solution is prepared
to give approximately the desired concentration by titrating
a weighed quantity of a primary standard
secondary stanwatdard
