INTRODUCTION TO INSTRUMENTAL ANALYSIS
Fall, 2001
Chemistry 382/378
St. Olaf College
© Professor John P. Walters

This fall marks the beginning of my 20th year at St. Olaf and the 19th offering of the combined class and lab in Instrumental Analysis. This course combination is a robust attempt to bridge your undergraduate environment with that of the beginning professional world, be that in advanced graduate work, the health-related professions, government labs and agencies, the legal professions, or the industrial sector.

As undergraduate students today, you each are in an unusual position. The opportunities for advanced education and work are many, but not unless you have the right combination of skills and interests. Strong technical skills, coupled with a desire and ability to interact in small groups ("teamwork") and communicate well are key factors. These are the exact focal points of the 382 and 378 courses.

Additionally, people today move within and between jobs and professions with far more fluidity than has been true in the past. The kinds of job changes are often between very different fields, and the skills a person has within one technology may not carry over to another. More than ever, you have to be able to reinvent yourselves in new contexts. This is exactly what we do in our labs, and your experiences there will help you understand how to engage a new technology or new professional task effectively even when you do not have the time and resources to go through a lengthy set of prerequisites.

Lab/Class Interactions

At the onset, it is important that you understand the structure of these two courses. The 378 laboratory is set up as an analytical methods development lab for building or exploring new approaches to the Role-Playing experiments that are used here and in other schools in the earlier courses in analytical chemistry. Role-Playing as such will be used in some sessions, while in others pairs of people will interact.

The first four computer-based interfacing experiments will be done individually. In all cases, the lab sessions are intended, by design, to be small, and are limited to a maximum of four people per afternoon. They are non-competitive, and intended to allow full interaction and sharing between people in a session, as well as between sessions themselves.

Sharing and interacting between lab sessions is unusual in most academic environments. Seldom do you, as students, even know what is happening in a lab session that meets at a different time than your own. That is not true here. It will be up to the people in one lab session (a group of 4 role players) to know well exactly what is going on in the other two lab sessions, and why. This is a form of communication I call technical "lateraling". It will be done by e-mail, by file sharing, by personal discussion, and by combined staff meetings. It will add a dimension to our course that is unique.

In addition to developing your communication skills, technical lateraling offers another advantage to us. Some "methods development" experiments we will work on are too intricate, too complex, or too detailed to be completed in a single afternoon’s lab session. In that case, the Group that meets on Tuesday may hand off its results to the one that meets on Wednesday, and so forth. Some projects have been "handed off" like this for up to three weeks, depending on the results of the work and the objectives of the project. This use of technical lateraling makes it possible to do research class experiments within a bounded course structure; it is an exciting way to handle labs in the undergraduate environment.

There is a strong emphasis on networking and sharing information between people in the class and lab sessions by computer. Resource sheets showing circuitry, pinouts, instrument functions, and other apparatus details are also shared, usually on the Analytical Chemistry Server computer.

These are discussed and used to plan the labs during a Staff Meeting starting at 3:00 PM each Monday. This is a meeting of all people in the course, and it reflects a "Management by Objectives" quality structure. Attendance is required at this meeting, since it is there that objectives, tasks, and techniques for the week's work are negotiated and developed, and there that the roles that require division of responsibility are defined and agreed upon.

In addition, it is during the Monday staff meeting that the person, or the Group, who will have lead responsibility for reporting out the results of that week’s lab is designated. The whole class knows who this person or Group is, and what information they will need to prepare the week’s poster, video, or demonstration. This final presentation is what I grade, and everyone else in the course gets the same grade as the person or Group who prepared the presentation. The grading criteria and expectations are presented in the Monday staff meeting.

The Texts

The 382 book is "Principles of Instrumental Analysis", by Douglas A. Skoog, F. James Holler, and Timothy A. Nieman (deceased), 5th edition. This book is well written. It offers the opportunity for you to cover a broad range of instruments, instrumental methods, and fundamental concepts, all at level on a par with "professional conventional wisdom". It is a unique book in doing so much, while not demanding excessive prerequisites. You will find this book on the desks of many professional people, as well as students.

You also will have a book of "Projection Templates", which are skeletal diagrams that I have drawn to project on the board and annotate during our classes. These help a great deal in preventing blackboard tag as we attempt to understand how the many parts of an instrument interact to give it a complex transfer function.

LabVIEW® Based Simulation Problems and Programs

You will have a LabVIEW®; based workbook on "Simulation Problems for Instrumental Analysis" to provide interesting, and even pleasing, alternatives to the problem sets taken from your textbook. As you soon will see, textbook problems in the area of instrumental analysis are not very deep, focus mainly on vocabulary, and can be done easily by referring to an appropriate formula or text passage in the book. The LabVIEW® based simulation problems, however, allow you to explore key properties of a circuit, an instrumental component or principle, or even an entire instrument for the relative consequentially of one or more of its interconnected parts. They also provide a new way to extend Role-Playing from the lab into the class environment.

The set of 19 LabVIEW® based simulation problems has been specifically designed with Role-Playing in mind. They allow roles of Manager, Chemist, Hardware, and Software to be used in collaboration for planning, designing, building, and running LabVIEW® based "virtual instruments" that help learn key ideas about instrumentation and instrumental methods. This mode of problem solving using the computer is an example of "group work" that is now being actively sought in the chemical industry. The ways in which the roles are assigned, and the grading procedures used for the simulation problems, are as follows:

Why do we learn and use National Instruments’ LabVIEW® in our Instrumental Analysis Course? Is it because we want to become computer programmers? Or does LabVIEW® represent something deeper than just computer programming? The answer to this question comes from the way others that you will meet after you graduate use software in their professional capacities. If they were using Visual Basic, then I would consider having you do that here as well. If they were using FORTRAN, or C, or C++, or whatever, in some capacity that would make you appear behind the times if you did not know that language, then I would have you use it here.

But in my opinion, the future does not lie in those languages, except in the hands of selected specialists. Rather, the bulk of the scientists and engineers who use computers on a daily basis as part of their profession have had to move away from languages that take so much time they become a big part of the cost of doing business. LabVIEW® is on the point of the new way of programming where the actual coding is but a small part of the investment you will make when using your computer as a problem-solving tool.

This is another reason that I have selected LabVIEW® for our course. I have written software using machine language, Fortran, Basic, Visual Basic, C, and Pascal. None of these efforts have produced so much, so quickly as has LabVIEW®. You will find too that you can do significant analytical work, quickly, even though you have had little or no formal "interfacing" training or experience.

LabVIEW® virtual instruments are not restricted to a particular kind of computer. The same virtual instruments that you will build on the Mac machines we use will run under Windows 98 or NT on a PC, or under Unix on a Sun. All that is required is functional equivalence. In other words, if a particular program expects to find an A/D board on the parent machine, then such a board must be present on any others to which it is transferred.

Your experience with LabVIEW® will be a "resume builder" that puts you out in front of the competition. The program is now in use in graduate research groups in analytical chemistry at the University of Wisconsin, the University of Arizona, and Indiana University (among others). It is a preferred environment in many federal labs. It also is a preferred environment in many industrial companies.

LabVIEW® will be used in working on "Simulation Problems". These are problems that are woven between the assigned textbook problem sets. Unfortunately, the problems that are included at the ends of the chapters of most instrumental analysis textbooks (ours included) are not robust, and may offer only token penetration into the depth of what makes up a true instrumental analysis. Perhaps this is unavoidable.

But, with LabVIEW®, what can be done is to prepare a virtual instrument, or a critical part of an instrument or instrumental concept, and explore what happens to it as component sizes or placement are changed, as input signals have more noise added to them, or as other key parameter changes are made. If this were a difficult task, then the cost of doing business could exceed the returns gathered over a more simplistic textbook problem. But, with your own copy of LabVIEW®, available either on your own machine or on a public machine, it is not hard to set up even complex instrument simulations.

This semester, each of you will purchase LabVIEW® 5 software at the start of the class. The textbook that accompanies this also will be in our bookstore. The whole package is expected to be in the vicinity of $75. The version of LabVIEW® that you will be using in the lab is the same as the student edition that you will be using for your simulation problems. This results from a major effort by the people at National Instruments to bring students into about the same degree of capability, as are professional development people. They have provided a remarkable similarity between the full professional edition of version 5 that we will use on the lab machines and the student edition that you will buy and keep. In simpler terms, this means that you can take your student edition out of St. Olaf when you graduate and expect it to be useful during your graduate work or on the job.

Simulation Problem Grading

Each problem handed in will start with full 10 points for the simulation. Making progressive reductions in this base score will set the final grade. Reductions follow in four categories.

1. Punctuality

The assigned and due dates for the simulations are given in the class calendar. The simulation is to be turned in, by Manager, electronically, on the day that it is due, any time before midnight. If this is met, then there is no penalty for punctuality.

a. 24 hours after due date = 50% reduction

b. 48 hours after due date = 70% reduction

c. More than 48 hours later = 80% reduction

2. Appearance

The final report turned in by Manager should have a crisp, professional appearance. Length is not at all an issue. The following features will be observed critically.

a. Spelling. 5 or more words misspelled = 30% reduction

b. Poor grammar and sentence structure = 20% reduction

c. Sloppy artwork on VI front panel = 20% reduction

d. Confusing layout on VI diagram = 10% reduction

3. Originality

a. The VI built from scratch and works = no reduction.

b. The VI taken from the server and partly modified and works = 25% reduction.

c. If the VI taken from the server and used as is = 50% reduction.

4. Technical Content

The VI must be used properly to meet the objectives of the simulation. The following apply.

a. All of the stated objectives explored and met = no reductions.

b. More than half of the objectives are met = 25% reduction

c. Less than half of the objectives met = 50% reduction

c. The Old College Try = 75% reduction

Role assignments and rotations for the fall, 1998 class are shown in the table below. Group assignments were made randomly. The simulation companies are grouped differently than the laboratory companies to encourage better communication between all members of the class. Note that the first three simulation problems are to be done alone. The grading criteria are ass given above. The point total will be 200 for all 19 problems, with the additional 10 being awarded subjectively for the quality of your professional collaboration during the semester.

 

Simulation Group "Tim"

Simulation Group "Dana"

Simulation Group "Mandy"

Sim

A

B

C

D

E

F

G

H

I

J

K

L

1

alone

alone

alone

alone

alone

alone

alone

alone

alone

alone

alone

alone

2

alone

alone

alone

alone

alone

alone

alone

alone

alone

alone

alone

alone

3

alone

alone

alone

alone

alone

alone

alone

alone

alone

alone

alone

alone

4

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

5

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

6

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

7

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

8

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

9

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

10

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

11

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

12

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

13

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

14

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

15

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

16

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

17

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

18

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

19

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

Softwr

Mgr.

Chem.

Hdwr

 

Active Class Participation Points

Not every class session will be a lecture from the front of the room. Some will involve class workshops and computer projects. Some will be "dissections" of laboratory instruments. Most will involve some active participation on everyone’s part, ranging from completing drawings on the board to sharing the results of a distributed computation. These active roles will be part of the "class participation" score assigned after each session. Class participation thus has three parts to it. They are:

1. Not sleeping, at all -worth 1 point per class session.

2. Actively responding to questions from others in the class or from the front of the room (including short periods of voluntary blackboard work) – worth 1 point per class session.

3. Discussing and/or interpreting with others in the class the meaning of a key concept – worth 0.5 point per class session.

Each day that you, as an individual member of the class, do any of these parts, you may enter one point for each one that you do, up to a maximum of 2.5 points, into the score sheet below. This will be turned in to me at the end of the semester for a total of 100 points (7.5-point bonus for accurately keeping track of your own scores.).

Self-Scheduling Examinations

Examinations (except for the final) in our course are scheduled in a unique manner. They are given out in class on a certain day, and picked up on another day. During the time between these days, you can work on them whenever and wherever you wish, but without help and only in a one-hour period. They are taken under the honor system, and a pledge is provided with each exam. This system is called "self-scheduling".

Past students have helped develop the "self-scheduling" examination procedure. Much of what is offered this semester is due to your prior classmates efforts at evolving an examination procedure that avoids some of the stress and tension of a timed classroom event, while at the same time retaining the professional validity of an examination situation. If you respect the system, and use the St. Olaf Honor System as you do in other courses, it will add an element of humane relief to what often is an anxiety-laden activity.

Self-Scheduling Examination Grading

• There are four of the above "self-scheduling", one-hour duration examinations, each worth 100 points and totaling 40% of the total course grade, given according to the times shown on the class calendar.

• These are not "take-home" exams in the conventional sense, in that they must be completed on the honor system, closed book and without assistance from another person or source, all within a proscribed continuous time interval. They are self-scheduling in the sense that they will be handed out in sealed envelopes on an announced day, and each person may choose the time and place at which they desire to work the exam. At the end of the proscribed time period, the pledge is signed (or not) and the examination is resealed in the original envelope. It is then handed in at the start of class on the scheduled date. Each examination will have, typically, four to five problems taken from:

• The examination questions will be graded individually, and scored "digitally" according to the following criteria:

(a.) CONCEPT ERROR, being a 50% reduction in the full question weight if the concept is incorrect, or the sense of direction incorrect, leading to an ultimate incorrect conclusion, interpretation, or numerical answer.

(b.) SET-UP ERROR, being a 30% reduction in the full question weight if the concept is correct but the way in which variables are set up in equations, algebraic manipulations done, or graphical interpretations made leads ultimately to an incorrect conclusion, interpretation, or numerical answer.

(c.) MATH or LABELING ERROR, being a 20% reduction in the full question weight if the concept and set-ups are correct but small errors in arithmetic, graphical interpretations, nomenclature (definitions), or instrument labeling leads ultimately to an incorrect conclusion, interpretation, or numerical answer.

The ACS Final Examination

The class and the lab are organizationally separated at St. Olaf only by historical precedent. In the professional world they seldom are, with the exception of the occasional staff meeting and seminar. It is up to you to be intellectually active in both, and to bring them together in your thinking. It is to your professional benefit. To reward those who do, the ACS final examination will take questions from the text, cover to cover, from all of the simulation problems, and from your lab experiences, regardless of what is formally discussed in class.

As you inspect your class calendar, you will see that we do not use material from all chapters of the book in class or problem activities. The final exam for the course will have questions on it from all of the chapters in the book, and the required independent reading assignments are indicated in the class outline just before and just after the appropriate examination dates. It is expected that you will do this reading. You can prepare for your final by a regular program of reading, started early in the semester, and continued up until the day of the final exam.

The ACS Final Examination Grading Procedure

The ACS final examination is worth 200 points. This examination will be a very slightly edited version of the current "ACS Certification Examination in Instrumental Analysis". It will consist of (usually) between 50 and 75 multiple choice questions based on the profession's collective understanding of what constitutes "conventional wisdom" in the area. The examination will be precisely timed at 2.0 hours, and will be held on the honor system, in class, on the day specified for this course by the College. All questions will be graded right or wrong, with no partial credit, but not "right minus wrong".

Not all of the material on this ACS final examination will have been explicitly covered in class, but, all of it is covered in the class book, Principles of Instrumental Analysis. Additional emphasis on mass spectrometry "cracking patterns" will occur in a final simulation problem. Questions from the problem sets and simulation problems concerning GC, MS, and GC/MS, will be emphasized on the final exam.

This examination reflects approximately 20% of what is expected of you at the graduate school entry level and/or as a certified, beginning BS chemist in the industry. There are equivalent examinations in Analytical, Biochemical, Inorganic, Organic, and Physical areas given upon entry into most competitive graduate programs, usually at the start and in the middle of your first year. Failure to pass them in at least three of the four areas may make you ineligible for the doctoral program, or, in some graduate programs, require passing a remedial course at a certain grade level.

 

The class has regular textbook and journal reading assignments and textbook problem sets. One person in the class who will be hired as a grader will grade these problem sets. The grader will score the problems from answers provided in the text "answer manual". This is done because there cannot be anyone here at St. Olaf who has taken the course before (it is a senior course). LabVIEW® based simulation problems, and I will grade participation activities. It is important that you note that a premium is placed on punctuality. It is unwise to be late in handing in work, except in the case it is late "due to circumstances beyond your control".

 

Disclaimer