ANNEXQuality criteria for validated analytical methods for sampling, identification and characterisation of primary smoke products
1.Sampling
The basic requirement is to obtain a representative and homogeneous laboratory sample.
The analyst shall ensure that samples do not become contaminated during sample preparation. Containers have to be rinsed with high purity acetone or hexane (p.A., HLPC grade or equivalent) before use to minimise the risk of contamination. Wherever possible, apparatus coming into contact with the sample shall be made of inert materials e.g. glass or polished stainless steel. Plastics such as polypropylene are to be avoided, because the analyte can adsorb onto these materials.
All of the sample material received by the laboratory is to be used for the preparation of test material. Only very finely homogenised samples give reproducible results.
There are many satisfactory specific sample preparation procedures which may be used.
2.Identification and characterisation
2.1.Definitions
For the purpose of this Annex the following definitions shall apply:
:
The mass of the material after abstraction of the solvent, which normally is water.
:
The part of the solvent free mass, which is volatile and analysable by gas chromatography.
:
Results of a descriptive analysis, which identifies substances present in the primary product.
:
Identification of the major physical-chemical fractions and quantification and identification of the chemical constituents.
:
Limit of Quantification
:
Limit of Detection
:
The single-laboratory standard deviation, calculated from results generated under repeatability conditions as defined in ISO standard 5725-1(1) (= repeatability standard deviation estimated in a single laboratory approach according to the Harmonized Guidelines for Single-Laboratory Validation of Methods of Analysis(2)).
:
The average within laboratory standard deviation, calculated from results generated under repeatability conditions as defined in ISO standard 5725-1(1) in a collaborative trial with a minimum of eight laboratories conducted according to the Protocol for the Design, Conduct and Interpretation of Method-Performance Studies(3).
:
The between laboratory standard deviation, calculated from results under reproducibility conditions as defined in ISO standard 5725-1(1) and according to the Protocol for the Design, Conduct and Interpretation of Method-Performance Studies(3).
:
Relative single-laboratory repeatability standard deviation (Si expressed in percent of the measured value),
:
Relative average repeatability standard deviation (Sr expressed in percent of the measured value),
:
Relative reproducibility standard deviation (SR expressed in percent of the measured value).
2.2.Requirements
Without prejudice to Article 11 of Regulation (EC) No 882/2004, the validated method for identification and characterisation to be selected by the laboratory shall comply with the quality criteria indicated in Tables 1 and 2.
Table 1
Quality criteria for methods for identification and quantification of chemical constituents in the solvent free mass and the volatile fraction of primary products
Parameter | Value/Comment |
---|---|
Solvent free mass | At least 50 % by mass shall be identified and quantified |
Volatile fraction | At least 80 % by mass shall be identified and quantified |
Table 2
Minimum method quality criteria for analysing Polycyclic Aromatic Hydrocarbons (PAHs)
a Over the whole analytical range. | |||||||
b The RSDi, RSDr and RSDR values are relatively high due to the low stability of the analytes in primary smoke condensate. | |||||||
c Corrected for recovery. | |||||||
Analyte(s) PAH | RSDi a | RSDr a | RSDR a | LODc | LOQc | Analytical rangec | Recoverya |
---|---|---|---|---|---|---|---|
% | % | % | μg/kg | μg/kg | μg/kg | % | |
benzo[a]pyrene | 20 | 20 | 40 | 1,5 | 5,0 | 5,0-15 | 75-110 |
benzo[a]anthracene | 20 | 20 | 40 | 3,0 | 10 | 10-30 | 75-110 |
cyclopenta[cd]pyreneb dibenzo[a,e]pyreneb dibenzo[a,i]pyreneb dibenzo[a,h]pyreneb | 35 | 35 | 70 | 5,0 | 15 | 15-45 | 50-110 |
chrysene 5-methylchrysene benzo[b]fluoranthene benzo[j]fluoranthene benzo[k]fluoranthene indeno[123-cd]pyrene dibenzo[a,h]anthracene benzo[ghi]perylene dibenzo[a,l]pyrene | 25 | 25 | 50 | 5,0 | 15 | 10-30 | 60-110 |
ISO 5725-1: Accuracy (trueness and precision) of measurement methods and results — Part 1: General principles and definitions. Geneva, 1994.
Thompson, M., S.L.R. Ellison, and R. Wood, Harmonized Guidelines for Single-Laboratory Validation of Methods of Analysis. Pure and Applied Chemistry, 2002. 74(5): pp. 835-855.
Horwitz, W., Protocol for the design, conduct and interpretation of method-performance studies. Pure and Applied Chemistry, 1995. 67(2): pp. 331-343.