Analytical Chemistry Introduction , Qualitative and Quantitative Analysis Applications

What is Analytical Chemistry?

Analytical chemistry is concerned with the chemical determination of matter.

Determination

An analysis of a sample to find the identity, or/and quantity of the analyte

Sample is a small portion of matter which be subjected to analysis.

The sample consist of analyte and matrix

Analyte:  The component to be determined in a sample.

Matrix All other components in a sample except  the analyte.

The sample must be representative

Qualitative and Quantitative Analysis

Qualitative Analysis

The identification or detection of materials (elements, ions or compounds) in a sample

Identification

–       What is the identity of the substance in the sample?

For example, What chemical species are present in a given drug

 Detection

–       Does the sample contain substance X?

For example, Is there any lead (Pb) in this sample ?  

Many problems in analytical chemistry begin with qualitative analysis, like:

-      The chemical tests to identify inorganic ions.

-      The chemical tests to identify organic functional groups.

-      Identifying the products of a chemical reaction.

Quantitative Analysis

Determination of the quantity (amount) of material.

How much of one or more components are present in a sample?

 How much of substance X is in the sample?

e.g.  (How much lead is in this sample?),

Perhaps the most common analytical problem is a quantitative analysis. Examples of typical quantitative analyses include:

- The elemental analysis of a newly produced compound,

- Measuring the concentration of glucose in blood.

- Determining the concentrations of Cr in steel.

Much of the analytical work in clini­cal, pharmaceutical, environmental, and industrial labs involves quantitative analysis like determining the trace amounts of chemical species in samples.

Question

For each of the following problems indicate whether its solution re­quires a qualitative analysis, or a quantitative analysis.

Both analysis may be appropriate for some problems.

(a) A waste disposal site is believed to be leaking contami­nants  

      into the local groundwater.

(b) A pharmacist is concerned that a recent drug is a forgery.

(c) Airport security determines the presence of explosive materials   

      in luggage.

(d) Screening an athlete’s urine for the presence of a performance-enhancing drug,.

(e) A new law requires knowing whether automobiles are emitting  

      too much carbon monoxide.

(f) Determining the air­borne lead Pb.

Applications

Analytical chemistry has several important applications in almost all fields of science (medicine, pharmacy, environment, quality control, ….etc.)

Examples of Applications

•         The concentrations of oxygen O₂, carbon dioxide CO₂, glucose C₆H₁₂O₆, ionized cal­cium Ca⁺⁺, …etc. are determined in millions of blood samples every day and used to diag­nose and treat diseases.

•         The measurement of quantities of hydrocarbons, nitrogen oxides NO_x, and carbon monoxide CO in automobile exhaust.

•         Determination of active ingredient and other components in pharmaceutical preparations.

•          Analysis of artificial products during their production to achieve a desired properties.

•         Determination the amount of pollutants in food (e.g. mercury in fish). 

Analytical Chemistry The Chemical Analysis Treatment of analytical data Chemical Calculations