Guide for sampling and analysis of bisphenol A (BPA) in industrial effluent: chapter 8
Chapter 8
8.0 Laboratory Analysis
It is recommended that the analytical test be performed by a laboratory that is accredited by a Canadian accrediting body under the International Organization for Standardization standard ISO/IEC17025 entitled General Requirements for the Competence of Testing and Calibration Laboratories. It is also recommended that the analytical method used is accredited under Canadian Association for Laboratory Accreditation specifically for the analysis of BPA in water. The method should be able to report to a method detection level of 0.2 µg/L for clean water samples.
Since there can be so much variation in the chemical composition of industrial effluents, it can be challenging to predict what interferences could be present in a given effluent sample. However, a high concentration of dissolved solids (TDS) may interfere with the analysis, and one way to overcome this issue is through dilution of the sample. Typical method detection limits in clean water are on the order of 0.2 µg/L; if a sample requires dilution due to matrix interferences, the detection limit would be increased accordingly. In samples where high TDS may be an issue, it is recommended that the laboratory check the electrical conductivity, which is an indicator of the TDS level, prior to analysis. The laboratory can then use the appropriate dilutions based on this additional information.
During sample collection in the field, the sample collector should take note of whether the collected samples visually contain suspended solids, as they may have an impact on the amount of BPA contained in the sample. If the analytical method will require the sample to be filtered before analysis of BPA, the monitoring plan should include measurement of the suspended solids content in the sample.
In the event that hold times might be compromised because of geographic location of the facility in relation to the laboratory, a spiked sample should also be considered.