P1_Chp1 [Compatibility Mode]

7/23/2019 P1_Chp1 [Compatibility Mode]

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What is Analytical Chemistry? ualitative

Quantitative

Chemical Analysis

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Chemical Analysis

Volumetric lassware: i et

buret, volumetric flask,conical flask, graduated

, ,

Electronic anal ticalbalance, desiccator,furnaces and ovens, fume

,

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Chemical analysis

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Instrumental analysis

Automatic tiration(potential titration)

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Instrumental anal sis3

1 2VIS spectrophotometry

e erm ne ron n wa er samp e

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Anal sis Methods Chemical Analysis Instrumental analysis

Chemical analysis Instrumental analysisConcentrations of < 10-4 Manalytes : 10-2 M 10 -4 M

Labor work, long time Automatic work, shorttime

Simple tools Expensive instruments

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Classif of anal tical methodsMethods

Physical analysis

y co-c e caanalysis

Electrochemicalanalysis

Chromatography

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Classify of analytical methods

Concentrations of analytes in the smaple i h i > 1

High concentration (x = 0,1 100%) Low concentration (x = 0,01 0,1%)

Trace analysis (x < 0.01%)

i Wet sample preparation

ry samp e prepara on

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Classify of analysis methods -

- Al 3+, Ca2+ , Mg2+ :0.3000 g clay sample + 3 g

titrate wit EDTAstandard

,

then dissolved in HCl

- , e : e erm ne yVIS spectrometry

Concentration (%) 28.12 0.48 1.25 0.56 0.08

a) Method for sample preparation is

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2 3,

Fe2O3, CaO, MgO v TiO2 are.


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Lab skills

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e ne e

Problem

er orm t e

necessary chemicalseparation

Select a

Method Perform theeasurement

Representative

SampleCalculation the

Results andRe ort

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1.Define the 4. Prepare the Sample for Analysis

Sample type (gas, solid,

What is the problem(Qualitative and/orquantitative?),

qu , sso ve p ,

reagent), concentration,derivatize

2.Select a Method

Sample type, sample size,anal tes concentrations

, ,solvent extraction, solidphase extraction

5. Perform the Measurement

(large amounts or smallamounts), how much toolsor instrument available,cost s eed sensitivit

- Titrations, chromatography orelectrophoresis

6. Calculation the Results and

3.Obtain aRepresentative

epor

amp e Sampletype/homogeneity/size


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Sample

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The Anal tical Process Select a Method

Samp e type, samp e size, ana ytes,concentrations (large amounts or small

,or parts per billion (ppb) or parts per million

How much is needed, how sensitivity themethod must be

Tools or instrument available (cost, speed,sensitivit ,)

Are methods available in the chemicalliterature?


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The Anal tical Process Obtain a Representative Sample

Grab or spot samplingThe gross sample consists of several portions of thema er a o e e e .

The laboratory sample is a small portion of this, madehomo eneous.The analysis sample is that actually analyzed.

Replicate samples, or replicates, are portions of

material of approximately the size that are carriedthrough an analytical procedure at the same time and inthe same wa .


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The Analytical Process - ExampleAnalysis of dicamba (pesticide) inwater

Problem (Qualitative and quantitative) Select a Method

What kinds of water (lake, river, tap or

agricultural water) Concentration (ppm (mg/L) or ppb (g/L) (1 mg =

10 3 g; 1 g = 10 6 g)

-, ,Chromatography (GC) or High PerformanceLiquid Chromatography (HPLC))

Are methods available in the chemical

literature?


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The Analytical Process - ExampleAnalysis of dicamba (pesticide) inwater

Problem (Qualitative and quantitative) Select a Method

What kinds of water (lake, river, tap or

agricultural water) Concentration (ppm (mg/L) or ppb (g/L) (1 mg =

10 3 g; 1 g = 10 6 g)

, , -Chromatography (GC) or High PerformanceLiquid Chromatography (HPLC))

Are methods available in the chemical

literature?


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The Analytical Process - Example

Analysis of dicamba (pesticide) inwa er Problem (Qualitative and quantitative)

Select a Method

Sample amp ng me o

Prepare the Sample for Analysis

oncen ra on qu - qu ex rac on, sophase extraction)


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The Analytical Process Example Prepare the sample for Analysis

Water samples

Analyte? (acidic organiccompound).Concentrate Yes Ad ust to H 2

1000 mlCl

CO 2H

OCH3

Cl

Eliminating Interferences.

Extraction

Reduce solvent to final volume

(2 x 50 ml)

for HPLC

HPLC: High Performance liquid chromatographyLiquid-liquid extraction


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The Analytical Process - Example

Analysis of dicamba in water Per orm t e measurement

Calibration

ep ca es

Blanks


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The Anal tical Process- Calculate the Results and Reports

Laboratory NotebookLaboratory Report

Measurement Uncertainty

Si nificant Fi uresStoichiometric calculations

Documents

P1_Chp1 [Compatibility Mode]