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2019-10-09
1
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
ADVANCED ANALYTICAL METHODS
ANALYTICAL SCIENCE
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Pass of subject:
Laboratory part – dr Reczyński (L)Lecture part – exam (E)Seminar part – presentation (P)
Final evaluation = 0.5E + 0.3L + 0.2P
Forms:Lecture ~ 12 hSeminar ~ 5 hLaboratory 28 h
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Information sources:• lectures• net: http://galaxy.uci.agh.edu.pl/~kca/• manual: W.W.Kubiak, J.Gołaś (ed), „ Instrumentalne metody analizy chemicznej” Wyd. AKAPIT, Kraków 2005• R.Kellner, J.M.Mermet, M.Otto, M.Valcarcel, H.M.Widmer, “Analytical Chemistry: A ModernApproach to Analytical Science”, Wiley-VCH, Weinheim 2004 • Southampton Electrochemistry Group, “Instrumental methods in Electrochemistry” Ellis Horwood, Chichester 1990
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
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W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Results of anonymous quiz
2012 2013 2014 2015 2016 2018 2019
Good answers 35% 43% 40% 43% 45% 38% 37%
Wrong answers 25% 34% 44% 45% 35% 32% 32%
I do not know 40% 23% 16% 12% 20% 30% 31%
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Good answers in the levels of analyticalknowledge
2012 2013 2014 2015 2016 2018 2019
Basic level 67% 58% 52% 50% 53% 43% 44%
Intermediate level 17% 38% 37% 40% 40% 20% 29%
Advanced level 17% 31% 28% 30% 40% 58% 29%
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Areas of analytical science:
- Chemical composition analysis
Qualitative and/or quantitative information on chemical composition of material objects (sample).
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Areas of analytical science:
- Process analysis
Composition analysis with additional independent variable time
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Areas of analytical science:
- Distribution analysis
Composition analysis with additional independent geometric variables in micro- or macroscale
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W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Areas of analytical science:
- Structure analysis
Composition analysis with additional independent geometric variables in atomscale (nanoscale)
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
The result of analytical determination is always information of sample composition and uncertanity of this determination
Xsr – average concentration or content of specific compound (element – in case of elementar analysis, compound – in case of specific analysis or group of compounds in case of speciation analysis)
ε – uncertanty of analysis. May be expressed in various ways but must be presented
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
STEPS OF THE ANALYTICAL PROCESS
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
OBJECT OFINVESTIGATION
SAMPLE
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
DIMINISHED AND
HOMOGENIC SAMPLE
DIGESTED SAMPLE
OBJECT OF MEASUREMENT
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
MEASUREMENT SIGNAL
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W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
RECORDED SIGNAL
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
RESULT OF ANALYSIS
Co2O3 – 2.4±0.2%;
Al2O3 – 24.4±0.8%;
SiO2 – 54.5±1.5%;
Ba0 – 4.6±0.4%
ANALYTICAL PROCESS
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
OBJECT OF MESUREMENT
SAMPLE
SIGNAL
RESULT OF MEASUREMENT
RESULT OFANALYSIS
INFORMATION
HIDDENVARIABLES
OBJECT OFINVESTIGATION PROBLEM
STRATEGY OF SAMPLINGSAMPLING
SAMPLE PREPARATION
MEASUREMENT
REGISTRATION/EVALUATION
CALIBRATION
INTERPRETATION
PERCEPTION SOLUTION OF
THE PROBLEM
MEASURINGSYSTEM
CHEMOMETRICMETHODS
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
LIST OF THE PARAMETERS OF ANALYTICAL PROCESS
Accuracy Precision Sensitivity Linear range Limit of detection Limit of determination Selectivity Specifity Repeatability Reproducibility Uncertanity Traceability
OBJECT OFINVESTIGATION
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
ANALYTICAL PROCESS
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
OBJECT OF MESUREMENT
SAMPLE
SIGNAL
RESULT OF MEASUREMENT
RESULT OFANALYSIS
INFORMATION
HIDDENVARIABLES
OBJECT OFINVESTIGATION PROBLEM
STRATEGY OF SAMPLINGSAMPLING
SAMPLE PREPARATION
MEASUREMENT
REGISTRATION/EVALUATION
CALIBRATION
INTERPRETATION
PERCEPTION SOLUTION OF
THE PROBLEM
MEASURINGSYSTEM
CHEMOMETRICMETHODS
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SAMPLE (PRIMARY AND ANALYTICAL)
Chemical analysis is performed usuallyregarding small part of the object ofinvestigation. This small part is calledsample. The process of extracting the samplefrom the object of investigation is calledsampling .
Sampling - operation resulting in obtaining sample, which isrepresentative to the object of investigation in regard to aim ofanalysis.
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
SAMPLE
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Sampling is the most important stage of theanalytical process. The information obtainedas the result of the analytical process will benot better than quality of the sample.Quality of sample depends on the strategy ofsampling which must assure that sample isreprsentative.The sample must be representative inrespect to the object of investigation andthe analytical problem.
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Representative and non-representative sample
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Characteristic of sample which impact the sampling process
Solid, liquid, gas
Phase constitution
Homogenity
Size
Hardness
Voliatility
Durability
Size of the analytical sample P which is necessary to performingdetermination depends on determinability of the analytical methodA and the average content of determined substance G in theobject:
where:A – determinability of the method [g];G – assumed content of determined substance in the sample(mx mass of the determined substance, my mass of the samplematrix):
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
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Size of the sample n which should be taken from discreteobject (for example set of N pills) may be estimated roughly onbasis of square root:
More reliable and economic results are obtained fromhyphergeometric distribution, binormal distribution or Baye’stheorem. Statistical methods require to define confidence limitand assume number of analytical objects which may exceedlimiting concentration of analyte.
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Strategy of sampling
Random sampling – samplesare randomly extracted fromobject of investigation.
Systematic sampling –samples are extracted on thebasis of geometric or timescheme.
•Stratum sampling – very large object of investigation isdivided on several stratum (layers). At each stratum randomsampling is performed.
•Represenative sampling - very large object of investigation isdivided on several stratum (layers). At each stratumsystematic sampling is performed. Number of samples ineach stratum should be proportional to its size.
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Sample labelling – each container with sample must be labelled. The label should provide following information:
• venue of sampling
• time of sampling
• number of samples taken
• preservation or stabilisatin method (if any)
• for what method sample is intended
• additional information (who perform sampling, sample description etc)
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Requirements for sample containers:
• material – inert to sample constituents (also preventing adsorption and absorption)
• durability (during sampling and transportation)
• size (appropriate to sample volume)
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Sample containers
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W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Sample storage – samples should be analyzed as soon as possible. If interval between sampling and analysis time is longer nacessary is to use methods which prevents changes in the sample:
• low temperature (~4°C)
Laboratory refrigerators are equippedto keep an average temperature at+4°C while storing all different types ofsamples from reagents, whole bloodand culture media to test samples andbiologicals.
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
- deep freezing (-20°C; -40°C or temperature of liquid nitrogen)
The SWFSC Marine Mammaland Turtle Molecular ResearchSample Collection houses over70,000 DNA samples. Thesamples are stored in severalfreezers held at a constanttemperature of minus 80degrees Celsius.
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
- lyophilisation (freeze-drying)
Drying the samples to a powderform. Such samples can beaccurately weighed, easily sub-sampled and redissolved. Freezedrying is the preferred technology.Fast lyophilisation (LyoSpeed™)methodology developed byGenevac1 is implemented in theGenevac HT-12 centrifugalevaporation systems. The processof freeze drying requires threesteps:- Pre-freezing- Primary Drying- Secondary Drying
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
- application of preservatives, stabilizing-agents and other substances which prevents changes in the sample.
Influence of preservatives
Urine sample preservation (there is no single „all purpose” preservative): For determination of urea, ammonia, nitrogen and calcium- Hydrochloric acid is used (2 N or
concentrated HCL) For determination of sodium, potassium, chloride, bicarbonate, calcium, phosphorus, urea,
ammonia, amino acids, creatinine, proteins, reducing substances and ketone -thymol is used
For determination of ascorbic acid - acetic acid is used
W.W.KUBIAK - ADVANCED ANALYTICAL METHODS
Remember!
- Analytical process is the multistageprocess in which each stage isimportant and influence theuncertanity of final result.
- The sample MUST berepresentative to the object ofinvestigation