week 1 - QA/QC Flashcards
what is the difference between pollution and contamination
pollution is the anthropogenic input causing deleterious effects
contamination is any chemical substance or waste that has indirectly or directly been added to the environment by human activity that is higher than background levels.
what contaminants of concern are under the inorganics
cations (metals that are positively charged)
metalloids (arsenic, phosphorous etc.)
anions (non metals that are negatively charged)
what falls under a preliminary site investigation (PSI)
- Site identification
- Environmental setting
- Geology and hydrogeology
- Site use history
- Current and proposed use
- Site inspection
- Heritage values
- The PSI is then used to develop the CSM.
what is a detailed site investigation (DSI)
A DSI is required when;
* The preliminary site investigation indicates that contamination is present or is likely to be present, and
* The information available is insufficient to devise site management strategies.
A DSI should;
* Identify the nature of contamination,
* Delineate its lateral and vertical extent so that risk can be assessed, and
* Provide the basis for the development of a remediation or management strategy (if required).
what are the 3 phases of assessment
phase 1: assessment
phase 2: investigation
phase 3: remediation
describe the difference between QA and QC
Quality assurance (QA) = actions taken to design and conduct a safe and effective investigation.
Quality control (QC) = procedures used to verify that the investigation is safe and effective.
what field quality assurance is needed
- Appropriate containers, sampling, preservation and storage,
- Decontamination (e.g. cleaning of tools) before sampling and between samples,
- Maintenance of the sample environment to minimise sample contamination and analyte losses (e.g. zero headspace), and
- Delivery to the laboratory in good condition and within the timeframes required for the required analytes (e.g. refrigeration).
what field quality control is needed
- Involves monitoring and measuring the effectiveness of the QA by comparison with the relevant data quality objectives.
These may include;
* For water – Trip blanks, Trip spikes, Field blanks, Rinsate blanks.
*For soil/sediment – blanks, blind replicates, split samples.
* Field duplicates (for intra-(within) lab - 1 in 10 samples.
* Field triplicates for inter-(between) lab - 1 in 20 samples.
what is the holding time for acid sulfate soils that have been frozen
24 hours
within what time does water sample pH need to be sampled
within 6 hours
what are some passive water sampling techniques
Diffusive gradients in thin film DGT - accumulates analytes over time
Passive vapour diffusion PVD - used for VOCs in air or water
semi-permeable membrane device SPMD - samples chemicals dissolved in surface water, mimicking the bio concentration of organic contaminants in fatty tissues of organisms.
what is the difference between accuracy and precision in sampling
precision refers to its repeatability or reproducibility.
can the analysis be repeated under the same conditions and reproducibility is can the analysis be reproduced by a different analyser.
accuracy is how close it is to a CRM
what is the general order of extraction of analytes from any media
Exchangeables, carbonates, sulfates, Fe-Mn and silicates.
