1 / 8

CHM 410/1410 Lecture 2 Environmental Sampling

CHM 410/1410 Lecture 2 Environmental Sampling. Environmental sampling. Two things to consider: Size of the samples required Number of samples required. Size is determined by detection limits Do you mind non-detects? Government monitoring programs vs. research into contaminant disposition.

aisha
Download Presentation

CHM 410/1410 Lecture 2 Environmental Sampling

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHM 410/1410Lecture 2EnvironmentalSampling

  2. Environmental sampling • Two things to consider: • Size of the samples required • Number of samples required • Size is determined by detection limits • Do you mind non-detects? • Government monitoring programs vs. research into contaminant disposition

  3. Environmental sampling • Two things to consider: • Size of the samples required • Number of samples required • Size is determined by detection limits • Do you mind non-detects? • Government monitoring programs vs. research into contaminant disposition Number is determined by spatial resolution required • Trying to see differences? • How well characterized does the situation have to be? Use these principles to design a sampling protocol

  4. Extraction Analysis Field blanks Extraction blanks Instrumental blanks Quality Control(QC) Contamination – an analytical chemist’s worst enemy Need to control and understand contamination at all steps: Sampling Find Contamination – work backwards to identify the source • Once source is identified, make changes to reduce contamination • Change sampling technique or container • New extraction reagents or location or technique • Clean instrument

  5. Quality Control(QC) Extraction efficiency – need to understand loss of material during extraction This is done using a Spike and Recovery experiment Add chemical of interest “Spike” Extraction Conc in extract Extraction efficiency X 100 = Conc in spike “Clean” Matrix Extract 5 83% X 100 = 6

  6. What if you can’t find a “clean” matrix?

More Related