Lecture 1-3

Question 0

Selenium^(c,k) means?
What is INAA?
What is GFAAs?

Answer 0

Instrumental analytical methods used to analyze SRM.
Instrumental neutron activation analysis.
graphite furnace atomic absorption spectrometry - make sure two methods get the same [].

Question 1

Analyte [] in a sample: Major ____; minor ____; trace ____.
SRM stands for ? NIST stands for ?
1ppm = ____
1ppb = ____

Answer 1

> 1% 0.1-1% <0.1%
Standard Reference Material
National Institute of Standards and Technology
1mg/L 1ug/L

Question 2

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 ____.

Answer 2

s= standard deviation s^2 = variance s(%) = 100*s/x (bar)
small precise larger
greater accuracy
unvertainty

Question 3

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.

Answer 3

2 chromatography methyl group
light intensity
mobile phase dimer Intensity

Question 4

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 ____.

Answer 4

quantity
detector    quantity    each
standard solutions
y = peak height (cms)
x = analyte [] (parts per million)

Question 5

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.

Answer 5

calibration curve
minimize square
y value x value
same

Question 6

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.

Answer 6

Blank standard analyte [] unknown
Substrate average absorbance blank corrected absorbance
graph corrected absorbance (y) amount (x)
2 6 []

Question 7

QA quantity assurance -> do to ___ the analytical results in terms of ____ and ____. International measurement evaluation program (Belgium) - __ ____ in water measurement.

Answer 7

verify accuracy precision

Pb []

Question 8

UV-vis-spectrophotometer measures ____ ____ ~ ____ of protein. Absorbance from black:

• ____ of reagents
• ____ in reagents
• ____ species

Answer 8

light absorbance amount
color
impurities
interfering

Question 9

Basics of QA: 1. ___ data, ____ measurements 2. ____ data: __’s derived from applying a ____ procedure to ____ data. 3. ____: ____ reported after ____ analysis of ____ data: __, _, ____ ____.

Answer 9

raw individual
treated []’s calibration raw
results quantities statistical treated
x(bar) s confidence interval

Question 10

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.

Answer 10

purposes
kind ways
precise accurate
[hydrocarbon] threshold value microbe

Question 11

Define “specifications”:

Answer 11

• how good must numbers be and what precautions in analytical procedure.

Question 12

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.

Answer 12

[hydrocarbon] less
position air volatilization/ degradation
room Microbes
temperature

Question 13

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.

Answer 13

precision
standardized SRM []
purity contamination apparatus

Question 14

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.

Answer 14

exceeds below

below above

Question 15

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.

Answer 15

distinguish lower
Method all analyte analyte procedure subtract
Field method sampling

Question 16

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 ____ ____.

Answer 16

spike analyte decreased matrix everything
known sample calibration curve

Question 17

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.

Answer 17

large instrument

performance blind unknowns known

Question 18

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 ___ ____.

Answer 18

Standard operation procedures
initial rigorously false
Assessment analytical within results use objective(s)

Question 19

API stands for?
____ ____: process of ____ analytical method acceptable for purpose.
API = ___ [], method requirements for regulatory submission: 1.____ 2. ____ 3. ____ 4. _____5.____ 6. ____

Answer 19

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)

Question 20

Method specificity: ____ of analytical method to ____ analyte from everything else that ____ be in sample electrophoresis: substances ____ by differing rates of ____ in an electrical field.

Answer 20

ability distinguish
might separated
migration

Question 21

Linearity: how well is response ____to quantity of analyte; how well does ____ ____ follow a ____ line.

Answer 21

proportional
calibration curve
straight

Question 22

Target [] of API in drug formulation known-> test ____ of calibration curve with _ standard solution’s spanning range form __ to __ times of expected [].

Answer 22

linearity 5

0.5 to 1.5

Question 23

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 _.

Answer 23

15 3
linearity correlation coefficient
y blank
0

Question 24

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.

Answer 24

SRM
2
blank       known       matrix
standard addition
spiking

Question 25

Precision: how well ____ agree with one another (small _); autosamplers in ____ and ____ have improved precision by factor ___.

Answer 25

replicates s
chromatography and GFAAS
3-10

Question 26

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)

Answer 26

reproducibility >=10
reproducibility
decreases
variation/relative

Question 27

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. ____

Answer 27

linearity, accuracy and precision
[] []
correlation coefficient
spike
interlaboratory

Question 28

____ 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 ____.

Answer 28

Limits of detection quantification
significantly different noise
1% positive
50% absent signal

Question 29

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).

Answer 29

blanks
minimum
1-5
7
slope

Question 30

Minimum detectable [] = ____ ____ (DL) = _ s/m. Signal 3 X noise-> detectable-> no accurate measurement. Lower limit of quantification (LOQ) = _ s/m

Answer 30

detection limit 3s/m

10s/m

Question 31

Reporting limit: [] below which regulations says that a given analyte is reported as “___ ____”. Does not mean analyte is ___ ____! ___ times higher than __.

Answer 31

not detected
not detected
5-10 DL

Question 32

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.

Answer 32

trans

trans

Question 33

Robustness: ____ of analytical method to be ____ by small ____ changes in operating parameters (injection volume, detector lenda, room T, etc.).

Answer 33

ability
unaffected
deliberate

Question 34

Cause of ___ effect: other anions in ground water when sample composition complex and affects reading add ____ quantities of analyte to ____ and analyze.

Answer 34

matrix known unknown

Question 35

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.

Answer 35

same different
calibration curve
internal standard

Question 36

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.

Answer 36

[] [] linear

spike known

Question 37

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.

Answer 37

analyte (X) internal standard (S)

2. 30 response factor (F)
3. 30

Question 38

(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.

Answer 38

a= area of analyte signal
b= [] of analyte
c= area of standard signal
d= [] of standard
equal         twice
after

Question 39

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.

Answer 39

1. use objectives
2. specifications
3. assessment
   Method validation
   Standard addition
   Internal standard