CHMB16H3 Chapter Notes - Chapter 5: Dynamic Range, Blank Noise, Chromatography

55 views3 pages
2 Apr 2014
School
Department
Course
Professor
Chapter 5 Quality Assurance
Quality Assurance: procedures to follow in order to obtain the correct answer for
our purpose; the answer should have sufficient accuracy and precision
Raw Data: individual values of a measured quantity, i.e. volumes from a burette
Treated Data: concentrations or amounts found by applying a calibration procedure
to the raw data
Results: quantities that are reported, i.e. mean or standard deviation, after applying
statistics to treated data
Use Objectives: states the purpose for which the results will be used
Specifications: sampling requirements, accuracy and precision, rate of false results,
selectivity, sensitivity, acceptable blank values, recovery of fortification (spiking),
calibration checks, and quality control samples
Must collect representative samples and analyte must be preserved after the
sample has been collected
Accuracy: calibration checks, fortification recoveries, quality control samples,
blanks
Precision: replicate samples and replicate portions of same sample
False Positive: conclude that the results “YES” when in fact it is no
False Negative: conclude that the results “NO” when in fact it is yes
Selectivity: specificity: being able to distinguish analyte from other species in the
sample (matrix); avoiding interference
Sensitivity: the capability of responding reliably and measurably to changes in
analyte concentration; must have a detection limit lower than the concentrations to be
measured; choose a method that can detect the analyte at the concentrations expected
Detection Limit: the smallest quantity of analyte that is significantly different
from the blank
Reporting Limit: the concentration below which regulatory rules say that a
given analyte is reported as not detected
Blanks: account for interference by other species in the sample and for traces of
analyte found in reagents use for sample preservation; used to test a method’s
selectivity
Method Blank: a sample containing all component except analyte and is taken
through all steps of the procedures; Real Sample – Method Blank
Reagent Blank: containing all components except analyte but it not subjected to all
sample preparation procedures; change one reagent at a time
Field Blank: containing all components except analyte and has been exposed to the
site of sampling; detect any contamination from transport to and from the field
Spike Recovery: Spike: a known quantity of analyte added to a sample to test
whether the response to sample is the same as that expected from a calibration curve
Matrix: everything else in the sample other than analyte
Matrix Effect: a change in the analytical signal caused by anything other than the
analyte
Calibration Check: analyze solutions formulated to contain known concentrations of
analyte = standard solutions; preparing solutions based on literature range; replicate
Unlock document

This preview shows page 1 of the document.
Unlock all 3 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Chapter 5 quality assurance to the raw data statistics to treated data our purpose; the answer should have sufficient accuracy and precision. Quality assurance: procedures to follow in order to obtain the correct answer for. Raw data: individual values of a measured quantity, i. e. volumes from a burette. Treated data: concentrations or amounts found by applying a calibration procedure. Results: quantities that are reported, i. e. mean or standard deviation, after applying. Use objectives: states the purpose for which the results will be used. Specifications: sampling requirements, accuracy and precision, rate of false results, selectivity, sensitivity, acceptable blank values, recovery of fortification (spiking), calibration checks, and quality control samples. Must collect representative samples and analyte must be preserved after the sample has been collected. Accuracy: calibration checks, fortification recoveries, quality control samples, blanks. Precision: replicate samples and replicate portions of same sample. False positive: conclude that the results yes when in fact it is no.

Get access

Grade+
$10 USD/m
Billed $120 USD annually
Homework Help
Class Notes
Textbook Notes
40 Verified Answers
Study Guides
Booster Classes
Class+
$8 USD/m
Billed $96 USD annually
Homework Help
Class Notes
Textbook Notes
30 Verified Answers
Study Guides
Booster Classes