Standard deviation of the differences Di (SDi):

Repeatabilities standard deviation (Sr) g/1

Repeatability standard (Sr) % vol

Repeatability standard deviation (Sr) ug/g

The standard deviation of the laboratory can be used to assess the reproducibility of the method.

Standard deviation of the blank sample (determined under within-laboratory-reproducibility conditions)

Standard deviation of the containing sample (determined under within-laboratory-reproducibility conditions)

Standard deviation of the contaminated sample (determined under within-laboratory-rep reproducibility conditions)

Standard deviation of the sample containing the analyte at the permitted limit (determined under within-laboratory-reproducibility conditins)

within-run standard deviation

between-run standard deviation

the between-run standard deviation sb,

Standard deviation of reproducibility Sr = 1,20 mg/100 g.

Standard deviation of comparability SR = 2,50mg/100 g.

the within-run standard deviation sw, and in-house precision limit,

The within-run standard deviation sw may be used to construct control charts (see Annex II).

Sr= standard deviation of repeatability

SR= standard deviation of reproducibility

s = the estimated standard deviation of the actual volume of the contents of the batch,

sR= Standard deviation, calculated from results under reproducibility conditions.

RSDr= Relative standard deviation, calculated from results generated under repeatability conditions [(sr/

Use of the standard deviation method

Repeatabilities relative standard deviation (RSDr) (%)

sr= Standard deviation, calculated from results generated under repeatability conditions.

sR= Standard deviation, calculated from results under reproducibility conditions.

calculate the mean, the standard deviation and the coefficient of variation (%) for these concentrations,

The limit of detection may be set as 3 x the standard deviation of the solvent blank or of the background response.

Calculate the standard deviation of the mean measured content at the decision limit.

Find the mean concentration, standard deviation and the coefficient of variation (%) of the fortified samples.

The measure of precision usually is expressed in terms of imprecision and computed as standard deviation of the test result.

The value of the decision limit plus 1, 64 times the corresponding standard deviation equals the detection capability (ΓΆ = 5 %).

The value of the decision limit plus 1, 64 times the corresponding standard deviation equals the detection capability (β = 5 %).

The concentration at the permitted limit plus 1, 64 times the corresponding standard deviation equal the decision limit (a = 5 %).

RSDr= Relative standard deviation, calculated from results generated under repeatability conditions [(sr/

RSD R = Relative standard deviation calculated from results generated under reproducibility conditions [(sR/

The corresponding concentration at the permitted limit plus 1, 64 times the standard deviation of the within-laboratory reproducibility equals the decision limit (a = 5 %),

The value of the decision limit plus 1, 64 times the standard deviation of the within-laboratory reproducibility of the measured co ntent equals the detection capability (ΓΆ = 5 %),

The value of the decision limit plus 1, 64 times the standard deviation of the within-laboratory reproducibility of the measured co ntent equals the detection capability (β = 5 %),

Finally, the panel supervisor should make up a table with the gradings for the whole group and calculate the arithmetic mean and the degree of error (of the mean).

The corresponding concentration at the value of the decision limit plus 1, 64 times the standard deviation of the within-labora tory reproducibility equals the detection capability (ΓΆ = 5 %),

The corresponding concentration at the value of the decision limit plus 1, 64 times the standard deviation of the within-labora tory reproducibility equals the detection capability (β = 5 %),

RSDL relative standard deviations of the laboratory

The corresponding concentration at the decision limit plus 1, 64 times the standard deviation of the within-laboratory reproducibility o f the mean measured content at the decision limit equals the detection capability (ΓΆ = 5 %),

The corresponding concentration at the decision limit plus 1, 64 times the standard deviation of the within-laboratory reproducibility o f the mean measured content at the decision limit equals the detection capability (β = 5 %),

the curve must be linear, i.e. the standard deviation (s) of the differences between the measured responses (yi) and the corresponding value of the responses calculated from the regression line (zi) divided by the mean value (y) of all the measured responses shall not exceed 0-07:

The limit of quantification may be set as 5 x to 6 x the standard deviation of the solvent blank or of the background response or to apply a response that is above the background (induction factor 10 x the solvent blank) calculated from the calibration curve of the day.

Less precision is determined by a larger standard deviation (2).

The limit of detection for immunoassays is determined as 3 x the standard deviation, based on 10 replicate analysis of the blank, to be divided by the slope value of the linear regression equation.

Accuracy is expressed as trueness (difference between the mean value measured for an analyte in a certified material and its certified value, expressed as percentage of this value) and precision (precision is usually calculated as a standard deviation including repeatability and reproducibility, and indicates the closeness of agreement between the results obtained by applying the experimental procedure several times under prescribed conditions).

The percent standard deviation should not be above 15 % in a triplicate determination for each sample dilution and not above 30 % between three independent experiments.