Instrumental Methods of Analysis in Biology and Technology (6 ECTS)

Semester: 1st or 2nd

Code:

Coordinator: Luísa Barreira (lbarreir@ualg.pt)


We often work in a chemistry lab to do simple things as measuring a pH or the salinity of seawater. Or some more complicated stuff such as determining the protein concentration or the chlorophyll content of microalgae or even better: the fatty acid profile of a seaweed. All of these analyses require the use of a particular equipment: a pH meter, a spectrophotometer, GC-MS. Even though you sometimes work with this sort of equipment, do you really understand what is behind the numbers that they give you? Can you tell if a pH meter is properly calibrated? Do you know the difference between UV-vis absorbance and a fluorescence measurement? Are you planning on using AAS, HPLC, GC or some other techniques? Then this is the curricular unit for you.

The objectives of this course are: i) explain the basic concepts behind the different instrumental techniques that we often use in a laboratory to analyse and characterize biological samples (bio)chemically; 2) give you a glimpse of what you can do with them and how they can help you in your MSc thesis; and teach you how to correctly operate these equipment to ensure that you can trust your results. In this course we will work with potentiometry (e.g., pH measurement), spectrophotometry, spectrofluorimetry (e.g., fluorescence), atomic spectrophotometry, and both liquid and gas chromatography.


Workload

30 h of lectures + 40 h of labs + 98 h of independent work.

The student will use the time assigned as "independent work" to study for a written exam and write two reports.


Registration

As the registration for any elective is mandatory, please wait for an email by the MSc Coordinating Team requesting the names of the electives that you plan to choose for your 2nd year, 1st semester.


Evaluation

Final grade: 70% of theoretical assessment via a written exam + 30% of practical assessment. The latter grade will be the average of the grades obtained in 3 reports.


Syllabus


Lectures

  1. Review of basic concepts of data processing and uncertainty in quantitative chemical analysis.
  2. Methods of quantification: external standards (calibration curve), internal standard and standard addition method.
  3. Potentiometric techniques
  4. Molecular absorption spectrophotometry and molecular emission
  5. Introduction to atomic absorption and emission spectrophotometry
  6. Chromatographic techniques (liquid and gas chromatography)

Labs

  1. Potenciometry: Measuring pH. Calibration of a pH meter. Determination of the asymmetry potential and slope.
  2. Data Analysis: Development and application of spreadsheets for calculation and treatment of analytical data. Calculation of means and standard deviation. Linear regression.
  3. Molecular spectrophotometry (UV-vis Absorption Spectrometry): Determination of total phenolics in plant extracts.
  4. Molecular spectrofluorimetry: Determination of neutral lipids in microalgae by the Nile Red method.
  5. Quantification methods: Comparison of the calibration curve method and the standard addition method.
  6. Atomic Spectrophotometry (AAS): Determination of cadmium in a water sample by AAS. Comparison of atomization methods: flame and graphite chamber.
  7. Atomic Spectrophotometry (MP-AES): Determination of the mineral profile of edible organisms.
  8. Thin Layer Chromatography: Separation of lipid groups in microalgal extracts
  9. HPLC-UV: Quantification of gallic acid and salicylic acid in plant extracts.
  10. GC-MS: Analysis of essential oils in aromatic organisms.