Lecture 1-3 Flashcards
Selenium^(c,k) means?
What is INAA?
What is GFAAs?
Instrumental analytical methods used to analyze SRM.
Instrumental neutron activation analysis.
graphite furnace atomic absorption spectrometry - make sure two methods get the same [].
Analyte [] in a sample: Major ____; minor ____; trace ____.
SRM stands for ? NIST stands for ?
1ppm = ____
1ppb = ____
> 1% 0.1-1% <0.1%
Standard Reference Material
National Institute of Standards and Technology
1mg/L 1ug/L
s = ____; s^2 = ____; relative s (%) = ____.
Measurements with ____ s more ____ than those with a ____ s. Does not imply _____ ____. Single most important characteristic ofany result from analytical measurements: statement of its ____.
s= standard deviation s^2 = variance s(%) = 100*s/x (bar)
small precise larger
greater accuracy
unvertainty
One method to determine __ analyte at the same time: ____.
Separation in mobile phase of two compounds, similar -> caffeine vs. theobromine, one has more ____ -> distinguished. It can detect by ____ ____ -> ____ ____ full; -> molecule passing ____ light. ____ determines quantification.
2 chromatography methyl group
light intensity
mobile phase dimer Intensity
Peak height of each peak ~____ of each compound. Need to standardize ____ response to known ____ of ____ analyte. For pure theobromine and caffeine with ____ ____ with 10,25,50 and 100ppm. On the graph, y-axis is ____ and x-axis is ____.
quantity detector quantity each standard solutions y = peak height (cms) x = analyte [] (parts per million)
Method of least squares: often use in context of a “____ ____” to fit best line through data points. To ____ magnitude of + and - deviations -> ____ all deviations.
Two assumptions: 1. error in __ value > than that of __ values. 2. ____ s for all data.
calibration curve
minimize square
y value x value
same
Determine protein [], (protein usually colorless):
1. ____ solution preparation, ____ solution of ____. (covering range of __ expected from ____). 2. ____ ____ ____ of the ____ solution from each measured absorbance to get ____ ____. 3. make a ____ of ____ ____() vs. ____ of protein(). Good practice: at least _ replicates of sample - make a graph of data with _ . -> can reject bad data or repeat measurements.
Blank standard analyte [] unknown
Substrate average absorbance blank corrected absorbance
graph corrected absorbance (y) amount (x)
2 6 []
QA quantity assurance -> do to ___ the analytical results in terms of ____ and ____. International measurement evaluation program (Belgium) - __ ____ in water measurement.
verify accuracy precision
Pb []
UV-vis-spectrophotometer measures ____ ____ ~ ____ of protein. Absorbance from black:
- ____ of reagents
- ____ in reagents
- ____ species
light absorbance amount
color
impurities
interfering
Basics of QA: 1. ___ data, ____ measurements 2. ____ data: __’s derived from applying a ____ procedure to ____ data. 3. ____: ____ reported after ____ analysis of ____ data: __, _, ____ ____.
raw individual
treated []’s calibration raw
results quantities statistical treated
x(bar) s confidence interval
Analytical use objectives: 1. state ____ for which results will be used (ex customer needs) 2. ____ of data want to collect and ____ to collect. 3. how ____ and ____ needs to be; speed over time, cost. Example: treatment of oil -> decrease ____ in soil to ____ ____ by ____ activity.
purposes
kind ways
precise accurate
[hydrocarbon] threshold value microbe
Define “specifications”:
- how good must numbers be and what precautions in analytical procedure.
Soil sample: ____ on surface of soil, is ____ than the deep centre of the pile -> several samples needed from different ____; -> full container of soil packed, no ___ within; -> label it. (be careful of ____/____); -> not at ____ temperature, ice chest. ____ chew down hydrocarbons. Check the ____ in the container, if not right, no need to analyte.
[hydrocarbon] less
position air volatilization/ degradation
room Microbes
temperature
Test ____ of the device before analyzing. - use ____ material; - make sure ___ has the right __ as on the label, result acceptable close. - reagent ____ needed. (highest or introducing ____), tolerance of ____; model using.
precision
standardized SRM []
purity contamination apparatus
Rate of false results: even well executed procedures sometimes produce some false conclusions: statistical nature of sampling and measurement.
False positive : [] ____ legal limit when, in fact it’s ____ limit;
False negative: [] ____ legal limit when, in fact it’s ____ limit.
exceeds below
below above
Selectivity : able to ____ analyte from other species; detection limit must be ____ than expected []. Acceptable blank values: 1. ____ blank: sample containing ___ component except _____ taken through all steps of ____ ____ (____ from sample measurements.) 2. ____ blank: similar to ____ blank, but has been exposed to site of ____. This can tell us if analyte inadvertently picked up by exposure to field conditions.
distinguish lower
Method all analyte analyte procedure subtract
Field method sampling
Recovery of fortification: ____ recovery: sometimes response to ____ can be ____ by something else in sample (____ effect, ____ else in sample). Spike = ____ quantity of analyte added to ____ test if response as expected from ____ ____.
spike analyte decreased matrix everything
known sample calibration curve
Calibration checks: ____ number of samples -> check ____ continues to work properly.
Quality control samples (____ test samples/____), sample provided to analyst as ____ obtained results compared to ____ values.
large instrument
performance blind unknowns known
SOP stands for? Defines exactly what analyst has to do (____); must be ____ followed to prevent ____ results due to “short-cuts”.
____: 1. collect data which show that ____ procedure operates ____ specified limits. 2. do final ____ meet defined ___ ____.
Standard operation procedures
initial rigorously false
Assessment analytical within results use objective(s)
API stands for?
____ ____: process of ____ analytical method acceptable for purpose.
API = ___ [], method requirements for regulatory submission: 1.____ 2. ____ 3. ____ 4. _____5.____ 6. ____
Active Pharmaceutical Ingredient
Method Validation proving
pure
1.method specificity 2. linearity 3. accuracy 4.precision 5. range 6. limit of detection (DL/LOD) and quantification (LOQ)
Method specificity: ____ of analytical method to ____ analyte from everything else that ____ be in sample electrophoresis: substances ____ by differing rates of ____ in an electrical field.
ability distinguish
might separated
migration
Linearity: how well is response ____to quantity of analyte; how well does ____ ____ follow a ____ line.
proportional
calibration curve
straight
Target [] of API in drug formulation known-> test ____ of calibration curve with _ standard solution’s spanning range form __ to __ times of expected [].
linearity 5
0.5 to 1.5
Each standard prepared and analyzed 5 times: 3X5= __ standards + __ blanks. One measure of ____ is the square of ____ ____ R^2. Another criterion: _-intercept of calibration curve (after ____ subtracted form each standard) should be close to _.
15 3
linearity correlation coefficient
y blank
0
Accuracy (nearness to truth): 1. analyze an appropriate ___; 2. compare results from _ different analytical methods; 3. analyze ___ sample with a ____ addition of analyte (____ same as unknown); 4. ____ ____ of analyte to unknown. Because SRM + second analytical method often not available, ____ most common.
SRM 2 blank known matrix standard addition spiking
Precision: how well ____ agree with one another (small _); autosamplers in ____ and ____ have improved precision by factor ___.
replicates s
chromatography and GFAAS
3-10
Instrument precision: ____ when same quantity of sample repeatedly introduced (__ times). Interlaboratory: precision measure of ____ by different ppl in different laboratories, as [] of analyte ____ becomes poorer coefficient of ____/____ s: CV(%)=100*s/x(bar)
reproducibility >=10
reproducibility
decreases
variation/relative
Range: [] interval over which ____, ____ and ____ are all acceptable. Linear range: __ range over which measurable response. Define __ interval for which: 1. ____ ____ R^2 >= 0.995 2. ____ recovery 100+-2% 3. ____
linearity, accuracy and precision [] [] correlation coefficient spike interlaboratory
____ of ____ (DL/LOD) and ____ (LOQ): smallest analyte [] that is statistically “____ ____” from blank (____). DL -> _% change of concluding that blank has analyte -> false ____ and __% chance that analyte ____ because ____.
Limits of detection quantification
significantly different noise
1% positive
50% absent signal
Steps to follow: 1. measure n ____ (no analyte) -> y(blank) + s 2. ____ detectable signal y(dl) (___ ___ ___ y(dl) = y(blank) + 3s ) 3. prepare sample whose [] ~___ times DL 4. measure n replicate samples (n >= _) y(sample) 5. ____ signal: y(sample)-y(blank)~ m*[sample] (m is the ___ of linear calibration curve).
blanks minimum 1-5 7 slope
Minimum detectable [] = ____ ____ (DL) = _ s/m. Signal 3 X noise-> detectable-> no accurate measurement. Lower limit of quantification (LOQ) = _ s/m
detection limit 3s/m
10s/m
Reporting limit: [] below which regulations says that a given analyte is reported as “___ ____”. Does not mean analyte is ___ ____! ___ times higher than __.
not detected
not detected
5-10 DL
U.S. packaged food must state how much ___ fats present (heart disease). Reporting limit : ___ fats 0.5g/serving -> [] _ 0.5g/serving reported as 0. -> ____ serving size so [] less than 0.5g/serving.
trans
trans
Robustness: ____ of analytical method to be ____ by small ____ changes in operating parameters (injection volume, detector lenda, room T, etc.).
ability
unaffected
deliberate
Cause of ___ effect: other anions in ground water when sample composition complex and affects reading add ____ quantities of analyte to ____ and analyze.
matrix known unknown
Standard addition: standard ____ substance as analyte
Internal standard: ____
Internal standard: instrument response varies slightly run to run? ->____ ____ useless. Add known amount of ___ ____ to unknown from analyte.
same different
calibration curve
internal standard
Analyte signal area for X compared with that from internal standard S -> determine __ of X area under each peak proportional to __ of each species and ____ response to X to S. In practice we ____ solution of analyte with ____ amount of standard ->analysis.
[] [] linear
spike known
Detector response to each component similar? If both ____ (X) and ____ ____ (S) have [] of 10mM -> area under analyte peak might be ___ times greater for X for S: ____ ____ (F) is ___ times greater for X than for S.
analyte (X) internal standard (S)
- 30 response factor (F)
- 30
(a__)/(__b)= F(c__)/(__d)
When F=1, means detector responds ____ to X and S.
When F=2, means detector responds ____ as much to X than S. {X} and [S] are [] of analyte and standard ____ they have been mixed.
a= area of analyte signal b= [] of analyte c= area of standard signal d= [] of standard equal twice after
Basics of QA = what we do to get right answer for purpose, 1.write ____ ____ (how will you use results) 2. ____ (how good do numbers need to be) 3. ____ (were specifications achieved).
____ ____: analytical method acceptable for intended purpose.
____ ____: analyte in sample where matrix affects response.
____ ____: response varies from run to run.
- use objectives
- specifications
- assessment
Method validation
Standard addition
Internal standard
