Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:1850:p108
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 1850 (pt 108/117)
Character Range: 669134–675988

laboratory performance problems (matrix interference, invalid holding times…)
                                                                                                                                                                                       * matrix problems
Comparability
The confidence (expressed qualitatively) that data may be considered to be equivalent for each sampling and analytical event
Field considerations                                                                                                          Laboratory considerations                            Comments
Same SOPs used on each occasion                                                                                               Sample analytical methods used (including clean-up)  Same approach to sampling (SOPs, holding times…)
Experienced sampler                                                                                                           Sample PQLs (justify/quantify if different)          Quantify influence from climatic or physical conditions
Climatic conditions (temperature, rainfall, wind…)                                                                            Same laboratories (justify/quantify if different)    Samples collected, preserved, handled in same manner (filtered, same containers)
Same types of samples collected (filtered, size fractions...)                                                                 Same units (justify/quantify if different)

Representativeness
The confidence (expressed qualitatively) that data is representative of each medium present on the site
Field considerations                                                                                     Laboratory considerations                         Comments
Appropriate media sampled according to SAQP                                                              All samples analysed according to SAQP            Samples must be collected to reflect the characteristics of each medium
All media identified in SAQP sampled                                                                                                                       Sample analyses must reflect properties of field samples
                                                                                                                                                           Homogeneity of the samples
                                                                                                                                                           Appropriate collection, handling, storage and preservation
                                                                                                                                                           Detection of laboratory artefacts, e.g. contamination blanks
Precision
A quantitative measure of the variability (or reproducibility) of data
Field considerations                                                                                     Laboratory considerations                         Comments
SOPs appropriate and complied with                                                                       Analysis of:                                      Measured by the coefficient of variance or standard deviation of the mean or by RPDs
                                                                                                             * laboratory and inter-laboratory duplicates  Field duplicates measure field and laboratory precision
                                                                                                             * field duplicates                            Laboratory duplicates measure analytical precision*
                                                                                                             * laboratory-prepared volatile trip spikes
Accuracy (bias)
A quantitative measure of the closeness of reported data to the true value
Field considerations                                                                                     Laboratory considerations                         Comments
SOP appropriate and complied with                                                                        Analysis of:                                      Bias introduced:
                                                                                                             * field blanks                                    * by chemicals during handling or transport
                                                                                                             * rinsate blank                                   * from contaminated equipment
                                                                                                             * reagent blank                                   * from contaminated reagent
                                                                                                             * method blank                                    * during laboratory analysis
                                                                                                             * matrix spike                                    * during laboratory preparation and analysis (may be high or low)
                                                                                                             * surrogate spike                                 * precision of preparation and analytical method
                                                                                                             * reference material                              * during laboratory analysis
                                                                                                             * laboratory control sample                       * during collection/
                                                                                                             * laboratory-prepared spikes                        transport (may be high or low)

* Laboratory duplicates measure analytical precision when the sample is totally homogenous. When sample heterogeneity exists, laboratory duplicates (and intralaboratory splits) measure the sum of laboratory precision plus sample heterogeneity. High sample heterogeneity impacts confidence in data and may warrant additional sampling to increase confidence or detect hotspots.

19.7          Field QA/QC
Environmental practitioners should ensure that the following issues are addressed in the field QA/QC program and that appropriate documentation is included in the assessment report:
    * replicate samples are split in the field and submitted to two separate laboratories in accordance with the requirements of Schedule B3
    * the sampling program includes assessment