16 minutes reading time (3175 words)

    'Get Real'- Bridging the gap between secondary and tertiary

    Brynn Hibbert
    University of New South Wales

    Introduction

    A tertiary course in chemistry may be seen as a bridge between secondary school and the workplace. Starting a course at a university brings a student into contact with working chemists whose task is to not only add knowledge about the subject, but to give an awareness of what it means to be a professional chemist. The bridge that I shall discuss here therefore is concerned with that transition between bright young student and bright, young, maturing professional.

    One approach is to ask employers of chemists what they value in a graduate. It has been reported in this conference that the wish list of employers has more general personal skills than specific chemical skills. This supports much anecdotal evidence from university chemistry departments, visiting committees and RACI surveys. It is often the case that the would-be employer takes for granted the basic chemical skills, but it is important that universities heed the comments, and find sensible ways of providing what industry wants. Rather than providing separate 'problem solving skills', or 'public speaking' classes, we believe that integrating into the chemical curriculum the need to work in groups, problem solve, or present results, is the correct approach.

    This paper explores three scenarios of real world learning; giving marks for correct results, project-based subjects and using high-profile research in undergraduate courses. The 'get real' message will also be underpinned by a discussion of why 'getting real' should matter anyway, in the light of findings about the quality of analytical chemistry results.

    A general tone of these innovations is embodied in the title of this paper - 'get real'. If the student can be exposed to situations that are sufficiently real world like, then pertinent skills will be learned.

    Marks for results
    The analytical quality problem

    Analytical chemistry is at a critical point in its history. Used as never before in industry and commerce, hardly any goods cross a national boundary without analysis by seller and buyer, almost no trip to the doctor fails to generate a specimen for analysis, no facet of the environment now goes unsampled. Whether a direct result of this increased activity, or a parallel development to it, recent publicity has been given to claims that a significant fraction of chemical analyses are wrong. The US Food and Drug Administration (FDA) announced that one quarter of all medical pathology had to be repeated. The UK Government Analyst proposed that one third of chemical analyses were not 'fit for purpose'(1). There is discussion about how uncertainty should be treated in analytical chemistry, and even whether the term 'uncertainty', which took over from 'error', should not itself give way to 'certainty' (2). Bringing this debate to the attention of students may shake their confidence in the infallibility of their mentors, but may also impress them with the need for competence when dealing with life-and- death issues.

    Recent examples come from a series of studies funded by the European Union, called the International Measurement Evaluation Programme (IMEP) (3, 4).The programme offers reference values, established by primary methods, against which participating labs can evaluate their performance. The degree of comparability is thus established against the most objective references available at present. Two of the rounds (IMEP3 and IMEP6 ) were concerned with analysing water for trace elements. Two samples were sent to each of 169 laboratories in 29 countries. The samples containing 14 elements at trace levels (0.01 - 30 mmol kg-1) had been prepared by NIST and analysed by isotope dilution mass spectrometry to an expanded uncertainty (k = 2) of 2%. Each laboratory was invited to return the concentration of each element in each sample, an uncertainty range, the method used, whether the laboratory considered itself experienced in this analysis, and whether the laboratory was accredited by a national body. The results showed evidence of bias, with a number of laboratories returning values up to 3 orders of magnitude away from the assigned value. There was no correlation between the ability to determine the correct answer and the method used, the experience of the laboratory nor the level of accreditation. Many of the laboratories did not know how to express uncertainty. There was no obvious improvement between the rounds. The leader of the programme, Professor De Bièvre has come to the conclusion that the quality of analytical results depends on but one thing - the quality of the analyst. This is a heartening conclusion for an educator.

    Another example from pathology is the determination of lithium in blood. Lithium is used to treat certain types of personality disorders. It is given orally and blood samples must be analysed frequently in order to establish a correct dose for each patient Figure 1 shows the analyses of two samples containing 19 μmol lithium in serum by six pathology laboratories. All but one laboratory obtained high results. Indeed some laboratories could not tell the difference between a therapeutic and a toxic dose. The problem with this interlaboratory comparison is that using normal statistical methods to analyse the data the only correct laboratory would have been rejected as an outlier!

    The undergraduate laboratory
    The community of analytical chemists has long known that they are obliged to deliver results that are 'fit for purpose', i.e. capable of answering the client's problem within an agreed time frame and budget. One obvious aspect of this is accuracy. having discussed with the second year analytical class about the current concerns of the outside world, we then explain that we too will demand a high level of professionalism from them. In particular the majority of the marks for the class will be given for the correct answer (i.e. value plus uncertainty plus units), and that the excuse that "the method was correct, only I made a mistake in writing the answer down", will not attract much sympathy. The scenario of a hospital with grieving relatives of a patient, who was prescribed double the correct dose of a highly potent drug because the pathologist forgot a 2 in the calculation, usually suffices to concentrate the students' minds.

    It must also be pointed out that the right answer is not everything. A properly kept work book and an ability to show how the answer was arrived at are also essential. In these laboratory classes the analyses are not particularly realistic, being designed to teach a given method. We believe, however, that an emphasis on obtaining a proper answer will prepare the students for the project-based subjects that they will encounter in their third year.

    Project based undergraduate courses
    Laboratory projectsProject-based, group practicals are an excellent way of addressing the concerns of employers that students do not have enough group skills such as problem solving in teams and presenting work to others. While many departments have introduced this into final year subjects, the School of Applied Chemistry of Curtin University of Technology has demonstrated that such classes may also fit into second year curricula (5). The argument against this approach is that time that would have been spent rehearsing and learning basic chemical techniques is given over to the more general personal skills, and that there is a danger of turning out good problem solvers who are not equipped with basic knowledge about chemistry to solve anything. However, the message from employers is clear, these skills are essential and they are lacking in the majority of chemistry graduates.

    Figure 2 shows a typical brief given to two or three third year students who have chosen the analytical chemistry elective. The ten weeks of the project, which takes place in the four hour laboratory slot for that subject, is broken up into four weeks preparation, four weeks experimental work and two to finish off and write up. At the end of the preparation phase the group gives a presentation to the class, outlining the problem and the approaches they mean to use to solve it. In the final week, they give a second presentation with the results and conclusions. The long preparation time gives the students an opportunity to understand the client's problem, search the library and internet, discuss with people in the School (who may be senior technicians - a good source of help), and try out the technique if they are not familiar with it. The presentations are encouraged to be as professional as possible, using PowerPoint on overheads or computers. In 1998 we propose to ask some groups to give a presentation to a non-chemist client, who must be persuaded that the problem is in good hands even if she cannot understand all of the jargon. We also may arrange a courtroom drama, in which some of our Science-Law students will test the students' ability to defend their work in a hostile environment.

    Case studies
    Outside the laboratory, there is opportunity to give instruction through the contemplation of realistic scenarios. In an environmental subject, a number of case studies are worked through with the students, from the point of view of the analyst who is called upon to set up a program, or to determine the effect on the environment of chemical pollution. An example popular with the students is the collision of two ships in the Mississippi River Gulf Outlet in 1980, releasing an interesting cocktail of pentachlorophenol, hydrobromic acid, vinyl polymer and ethyl merciptan into the waterway (6). With a cost of half a million dollars per day the waterway was closed, important oyster beds and nearby New Orleans, the need for rapid and accurate analysis to establish the extent of the pollution and the efficiency of the clean up. As well as the obvious analytical aspects of sampling, the analysis of the target compounds in water, sediment and biological samples, problems such as capacity of the laboratory, maintenance of quality control and health and safety of personnel are also discussed. The problem allows the lecturer to introduce information piecemeal (as, of course, happens in practice) which requires the students to estimate when they do not have full knowledge. "How much PCP is likely to have been released?" "What concentrations should we be looking for in the water?" are questions that arise early in the discussion.

    Everyone is relieved to discover that only PCP was released in significant amount and that caused little damage to the environment. Of interest is that the species analysed as having accumulated the greatest amounts of PCP during the spill were humans taking part in the clean up operation.

    Research to learning
    An excellent way of enthusing students and giving them experience is to use the results of research in the undergraduate program. We were fortunate in having a project, the electronic nose, that had attracted some high profile media coverage, was straightforward to explain in chemical terms, and could be used by the students within the constraints of an undergraduate practical.
    An electronic nose
    Electronic nose technology embodies the concept of multiple, non-selective sensors giving signals that may be calibrated for a given range of gases (7). As its name suggests the idea is to ape the mammalian olfactory apparatus (the nose). A human nose has several million receptor cells with a few thousand different types, capable of distinguishing among about ten thousand odours. Present electronic devices are more modest in their complexity, having two to thirty sensors programmed for fewer than a dozen gases. The neural network processor of a mammal (the brain) also has the edge on the algorithms used by computers to unscramble the signals coming from the sensing device (8).

    Many different types of sensor are known, but the most popular is the Taguchi sensor based on a thin film of semiconducting tin oxide. Vapours that adsorb on the surface and can react with oxygen change the resistivity of the film. By doping. some partial selectivity may be imparted to the sensor.

    UNSW developed two and three-sensor devices that were calibrated for petrol vapour (as an equivalent concentration of butane) and carbon monoxide, both pollutants associated with automobile pollution. The portable device was used to check the exhausts of individual cars, and also as a mobile pollution monitor for measuring general levels in the air (Fig 3).

    Air pollution in Sydney

    Although air pollution in cities around the world is generally less than a decade ago, following the introduction of catalytic converters, and more efficient engines, air quality is still a matter of major public concern.

    When the Sydney Harbour tunnel was opened in September 1992, we were invited to monitor the tunnel using our portable analyser. On the day the tunnel opened we went through it with a TV crew and pronounced the air in the tunnel "better than in the Central Business District". Another TV station had picked up the story and two days later we found ourselves driving through the tunnel with our device monitoring the air.

    This time we met a wall of white fumes and the sensors' responses showed a great increase(Fig.€ 4). There had been a minor problem with the settings of the ventilation, which was quickly fixed, but the incident caused a certain amount of public interest. Newspapers took up the story with headlines such as "Tunnel trapping danger gases,' (Daily Telegraph Mirror, 3/9/1992), and "Uni sensor sniffs out air culprits" (The Australian, 5/9/1992).

    It is possible to build on this incident, using the media reports of the time to discuss questions like "what is the air quality in Sydney?", "How do we measure it?", "what do we measure?", "How should the results be communicated to the public?".

    A third year project

    One of the prototype sensors was given over to a third year analytical class and formed the basis of a practical experiment. The students are asked to go out onto the main road that passes the University (Anzac Parade) and measure levels of hydrocarbons and carbon monoxide near flowing traffic, at some pedestrian traffic lights, and on the median strip. A mobile telephone can send the results back to the School by FAX. The instrument is sensitive enough to pick up the exhaust signature from individual cars and trucks, and it is possible to build up enough information for the students to start a discussion on the nature of automobile pollution.

    As this device is a real research instrument, the undergraduates tend to interact with postgraduate students, and they gain some insight into the nature of research.

    Pollution in the university?
    The involvement of undergraduate students gained a boost in 1996 when the University moved its main vehicle entrance a few hundred meters up Barker Street. and re-established it opposite a child care centre. At peak times cars queuing to enter the University (particularly those turning right) were providing a source of automobile exhaust gases close to where kindergarten children were playing. Worried parents approached us to determine if the levels in the child care centre were in any way dangerous. Two students spent a summer vacation project making measurements. They discovered the problems of sampling and calibration, and of what in the vacation when the volume of traffic was considerably less than in term time. The results suggested that there was no evidence, from this study, that the levels of hydrocarbons and carbon monoxide were at all dangerous. Both students decided to stay in the School and take honours.

    Conclusions
    It is possible to find many instances in which the philosophy of 'get real' can be applied in an undergraduate chemistry degree. From the earliest times it can be impressed on them that results do matter, and that their progress will be measured in terms of the correct answers. In the outside world there may be little room for a good effort, but the wrong result. Project work, with groups of students being set realistic tasks, should be introduced as soon as possible. Here the level of realism is only limited by the imagination of the academic. Aspects of funding and cost may be introduced, the "clients" may suddenly change their mind in medias res, and the students may have to defend their results in a 'court of law'. Institutions with a thriving research culture can draw on that experience to provide interesting and pedagogically-sound examples to feed down to the undergraduate curriculum.

    One of the more important aspects of 'get real', is that the academics themselves have to be convinced that the examples are indeed realistic and worth taking seriously. Once enthused, the students do strive to do a professional job and, hopefully, carry on this philosophy to their employment when they leave the protective confines of university.

    Acknowledgments
    The third year analytical project laboratory in the University of New South Wales was conceived and is implemented by Dr G. Moran.

    The electronic nose and pollution monitor was developed with Professor P.W. Alexander now of the University of Tasmania, Launceston.

    References
    1. Hibbert D. B. (1997). Quality and integrity of Data, Proceedings 14th Australian Symposium on Analytical Chemistry Adelaide July 1997, ed S. Mcleod, Analytical Chemistry Division, Royal Australian Chemical institute, Melbourne, ISBN 0 909589 93 3.pp7-10.
    2. Sargent M. (1996). Confidence in Analysis. VAM Bulletin (Autumn 1996)pp 3-4.
    3. van Nevel L., Taylor P.D.P.,Ornemark U. and De Bievre P. (1996). International Measurement Evaluation Programme (IMEP) - 6: Trace elements in water. Report to Participants. European Commission, Brussels.
    4. van Nevel L., Taylor P.D.P., Ornemark U., Moody J.R., Heumann K.G. and De Bievre P. (1996). The lnternational Measurement Evaluation Programme (IMEP) (EP€: Trace elements in water'. Acred. Qual. Assur. 3 56-68.
    5. Dunn J.G. and Phillips D.N. (1998). Introducing second-year chemistry students to research work through mini-projects, J. Chem. Ed.75,866-869.
    6. DeLeon I.R., Ovedon E.B. and Laseter J.L. (1982). The role of analytical chemistry in a toxic substance spill into the aquatic environment, in Analytical Techniques in Environmental Chemistry 2.Ed J.Albaiges, Pergamon Press, Oxford, 1-18.
    7. Gardner J.W. and Bartlett P.N. (1994). A brief history of electronic noses, Sens. Actuators B, 18, 211 - 220.
    8. Hibbert D. B. (1998), Data analysis of Array Sensors, ARC Special Initiatives Program. Workshop on Electrochemically Based Microsensing Arrays, University of Wollongong, Feb 2-5, 1998 Ed G Wallace, Univ. Wollongong, ISBN 0-86418- 487-5.

    About the author
    Brynn Hibbert was born in England, receiving his honours degree and PhD from King's College, University of London. Trained as a physical chemist he was appointed Chair of Analytical Chemistry at the University of New South Wales in 1987.

    Brynn has an eclectic interest in chemistry and science. His major research areas are in electrochemistry and electroanalytical chemistry, and in chemometrics. He has published on electrodeposited fractals and has an interest in non-linear dynamics. At present he is developing sensitive 'electronic noses' with the Centre for Chemosensory Research at the University of New South Wales. His "Introduction to Electrochemistry" (Macmillan, 1993) is an undergraduate text on electrochemistry and includes anecdotes and stories on curious and little-known electrochemical facts. The material Frankenstein in Part II comes from this book.

    Brynn also has an interest in scientific fraud, both from professional scientists who should know better, and from back yard inventors who may not realise they are offering to violate the laws of the Universe.

    The Discovery of Ventolin
     

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