Analytical Chemistry at Howard Payne University

Instructors: Dr. Pamela Bryant, Dr. Derek L. Smith

Howard Payne course numbers

Quantitative Chemistry—CHE 3469

Instrumental Analysis—CHE 4469

Definition

Analytical chemistry is simply the study of the chemical composition of natural and artificial materials via the conduction of quantitative measurements.  In practice quantifying analytes in a complex sample becomes an exercise in problem solving.  In order to be effective and efficient, analyzing samples requires expertise in the chemistry that can occur in a sample, analysis and sample handling methods for a wide variety of problems (the tools of the trade) and proper data analysis and record keeping.

Synopsis

In order to meet these needs, analytical chemistry courses usually emphasize equilibrium, spectroscopic and electrochemical analysis and separations—all supported and substantiated by the rigorous application of statistics.

Analytical chemistry requires a broad background knowledge of chemical and physical concepts.  With a fundamental understanding of analytical methods, a scientist faced with a difficult analytical problem can apply the most appropriate technique(s).  A fundamental understanding also enables the chemist to identify when a particular problem cannot be solved by traditional methods and gives an analyst the knowledge that is needed to develop creative approaches or new analytical methods.

Methods of Detecting Analytes[1]

v  physical means

Ø  titration

§  gravimetric(mass-based)

§  colorimetric(evidenced by appearance or absence of color)

§  conductometric(characterized by Voltage or current change)

Ø  chromatography

§  flame ionization detection

§  ultraviolet absorption detection

§  thermal conductivity detection

§  mass spectral detection

v  via electromagnetic radiation (spectroscopy)

Ø  absorption

Ø  emission

Ø  scattering

v  electrochemical

Ø  Voltammetry

Ø  amperometry

Structure

Lecture

CHE 3469

In the first semester the student is introduced to the statistics that are required for reporting scientific data properly.[2]  The lecture proceeds to introduce concepts and calculations that will be required in order to complete the scrupulous laboratory methods that are employed.  While the emphasis in lecture is upon mathematical rigor related to standard volumetric and gravimetric techniques and chemical equilibria, techniques and concepts that are not available or readily demonstrable here in our laboratory are also discussed.  Examples are electrochemical methodologies and kinetic rate determinations.  Primary emphasis is on quantitative measurements by non-instrumental methods.

offered every other year in the fall

CHE 4469

The second semester in the analytical sequence consists of instrumental analysis (CHE 4469); an advanced-level study of the theories, techniques and practical applications of scientific instrumentation; beginning with a fundamental treatment of modern digital electronics.  The nature of electromagnetic radiation and its applications to ultraviolet-visible, infrared and atomic absorption spectrophotometry are discussed and illustrated.  The related theories of quadrupole and quadrupole ion trap mass spectrometry are studied and compared.  Separatory science is explored by the use of gas chromatography (GC) and high-pressure liquid chromatography (HPLC), coupled with both physical and spectrometric detectors.  The theories of nuclear magnetic resonance (NMR) and electroanalytical techniques are also covered.  In each case emphasis is placed upon the construction and operation of each apparatus, as well as appropriate methods of sample preparation; not merely the data that may be generated thereby.

This course sequence is challenging and fast-paced in order to cover the material needed to provide students with sufficient knowledge and expertise in analytical and instrumental science so as to perform well on the GRE, MCAT, ACS and other proficiency examinations.  Moreover, as Howard Payne University now offers the forensic science degree, these two courses will be of paramount importance to a successful career in multiple regulatory and investigative agencies.

At Howard Payne University the analytical student receives the same instruction that should be found in any analytical classroom at any university; but our classes are smaller, allowing the student to receive classroom instruction directly from a professor rather than a teaching assistant.  Also, the student has greater access to the professor outside of the classroom than might be found at a larger university.

offered every other year in the spring

Laboratory

These two courses are the most laboratory-intensive classes in the chemistry and forensic science degrees, including 8 and 6 hours of laboratory time per week, respectively.  At this level in the curriculum, students will work largely independently with a modicum of input from the professor:  provided detailed procedures and using skills taught in General Chemistry, students should be able to conduct the experiments as proficient chemists.

Given the level of scrutiny that follows many quantitative analyses, students are expected to conduct experiments with utmost attention to accuracy and reliability.  Furthermore, since these analyses are routinely employed professionally in critically important (Think “commercial” and “legal.”) scenarios, students are required to maintain notebooks as a permanent, verifiable record of their endeavors.

In the instrumental portion of the sequence, emphasis is placed upon machine operation and the study of how theory is implemented in the instruments’ construction.  A very hands-on approach is presented, and in some instances students even participate in maintenance and troubleshooting.  Sample preparation is also addressed.  Proficiency in each technique is verified by the students’ ability to qualify or quantify an unknown sample provided by the professor.

First Semester Experiments

Analyses will be selected from among the following typical experiments.

The Gravimetric Determination of Chloride in a Soluble Sample

The Gravimetric Determination of Tin in Brass

Titrimetric Determination of Potassium Hydrogen Phthalate in an Impure Sample

Determination of Hardness in Water

The Determination of Calcium in a Limestone

Preparing a Standard Silver Nitrate Solution

The Determination of Chloride by Titration with an Adsorption Indicator

Standardization of Iodine Solutions

Determination of Copper in Brass

Potentiometric Titration of Chloride and Iodide in a Mixture

The Determination of Iron in Natural Water

Spectrophotometric Determination of pH

chromatographic separation and analyses

Second Semester Experiments

electrochemistry

Infrared spectrophotometry

AA

Infrared spectrophotometry

Ultraviolet-visible spectrophotometry

Ultraviolet-visible spectrophotometry

NMR      (FID transient signal and spectrum analysis will substitute for data acquisition.)

GC-MS

Column GC

Capillary GC

LC



[1] Obviously, there are manifold ways to detect an analyte, and in each of the above general categories are a multitude of specific analytical techniques.  The techniques highlighted in blue are methods that are currently available in Howard Payne laboratories.

[2] As a seminal component of the forensic science major, as well as an essential aspect of the chemistry major, the course is presented from a forensic framework, and strict adherence to both precision and accuracy of data is enforced.