# Analytical Chemistry II and Laboratory

**Academic Year 2022/2023**- Teacher:

**Giuseppe SPOTO**

## Expected Learning Outcomes

The aim is to provide background information on instrumental analytical chemistry with specific reference to spectroscopy and electrochemistry.

## Course Structure

Class and laboratory experiments.

Should teaching be carried out in mixed mode or remotely, changes with respect to previous statements may be introduced, in line with the outlined syllabus.

According to safety requirements linked to the pandemic, learning assessment may also be carried out online.

## Detailed Course Content

1. Spectroscopy:

Electromagnetic radiation: wave-particle dualism, photoelectric effect and diffraction, Heisenberg's principle. Electromagnetic spectrum. Refraction, refractive index, Snell's law, total internal reflection. Interaction of radiation with matter: reflection, transmission/absorption, diffusion (Rayleigh, Mie, Raman). Absorption and emission of radiation. Atomic absorption. Molecular absorption. Vibrational and rotational motions. Fluorescence, phosphorescence.

2. Molecular spectroscopy - UV-vis

Transmittance, absorbance, Beer's law. Limitations of Beer's law. Photometer and spectrophotometer. Single beam spectrophotometer, Double beam spectrophotometer. Sources. Wavelength selectors. Transducers: photovoltaic cells, photocathodes, photomultiplier tubes, series of diodes, charge injection, coupled charge.

3. Molecular spectroscopy - infrared

General characteristics. Harmonic and anharmonic oscillator, dipolar moment of transition. Molecular vibrational modes. Main IR signals: functional groups area, fingerprint area. Dispersion spectrophotometers. Fourier transform spectrophotometers: Time domain and frequency domain, Fourier transform, Michelson interferometer. Sources. Detectors. IR spectrum characteristics and interference. Cells for gas and liquid analysis. Solids analysis. Diffuse reflectance. Total attenuated reflectance. Microscopy.

4. Molecular spectroscopy - Raman

General characteristics. Raman effect. Polarizability. Comparison with IR spectroscopy. Raman signal strength. Depolarization ratio. Resonance-enhanced Raman Scattering. Surface-enhanced Raman Scattering. Sources. Dispersive and Fourier transform spectrometer. Raman microscopy.

5. Atomic spectroscopy

Instrumentation for atomic absorption, emission and fluorescence. Atomic absorption. Atomic absorption instrumentation. Atomic emission spectrometry: inductively coupled plasma sources.

6. Mass spectrometry

Fundamental. Ion sources: ICP, EI, CI, FD, FAB. SIMS, LD-MS, MALDI, ESI. Mass analyzers: magnetic sector, quadrupole, time of flight, ion trap, ICR-MS. Mathieu equation, secular frequency, ion trapping, isolation, resonant excitation, SIM, MS / MS experiments, hyphenate techniques.

7. Electroanalytical methods

Galvanic cell. Electrode potential. Nernst equation. Electrolytic cell. Junction potential, salt bridge. Double electric layer. Electroanalytical methods. Ohmic potential. Electrode polarization: concentration, reaction, adsorption, desorption, crystallization, charge transfer, mass transport. Reference electrodes: hydrogen standard, calomel, Ag / AgCl. Indicator electrodes: first, second and third species, redox, membrane. Glass electrode: glass, interphase potential, asymmetry potential, calibration, alkaline and acid error. Combined glass electrode. Potentiometer, load error, voltage trackers. Main electroanalytical techniques: potentiometry, voltammetry, amperometry.

8. Statistics of repeated measures

Absolute and relative error. Types of errors. Accuracy and precision. Descriptive statistics: Histograms, Position parameters, mean, mode, median, quartiles. Parameters of

dispersion: variance, standard deviation, standard error, relative standard deviation. Probability distributions. Binomial distribution. Poisson Distribution, Normal Distribution, Standardized Normal Distribution, Student Distribution, χ2 Distribution, Fisher-Snedecor Distribution. Statistical Inference. Estimation theory, sample mean distribution, sample variance distribution. Central limit theorem. Confidence interval for the mean and for the variance and for the difference between two means. Hypothesis test. Significant figures. Correlation between variables, covariance, correlation coefficient. Linear regression: least squares method, standard deviation of the regression, slope, intercept and values deduced from the line, goodness of fit, coefficient of determination. Matrix effect, recovery, method of standard additions. Sensitivity. Limit of detection and quantification.

9. Construction of a photometer for absorbance measurements:

Printed circuits. Symbols for electronic components. Ohm's law, Kirchhoff's law, voltage divider and current divider. Resistances and related conventions. Intrinsic and extrinsic semiconductors, p and n dopants. Diodes: forward and reverse polarization. Light emitting diode (LED). Photoresistors. Operational amplifiers: comparison devices, voltage trackers, inverting operational amplifiers.

Photometric determination of iron in aqueous solutions.

10. Potentiometric titrations

Determination of the phosphoric acid content in Coca-cola by potentiometric method.

## Textbook Information

-Class notes

-Skoog, Leary, “Chimica Analitica Strumentale”, Edises.

-Skoog, West, Holler, Crouch, “Fondamenti di Chimica Analitica”, Edises

-Rubinson, Rubinson, “Chimica analitica strumentale”, Zanichelli

## Course Planning

Subjects | Text References | |
---|---|---|

1 | Spettroscopia | Skoog, Leary, “Chimica Analitica Strumentale”, Edises |

2 | Spettroscopia UV-vis | Skoog, Leary, “Chimica Analitica Strumentale”, Edises. |

3 | Spettroscopia infrarossa | Skoog, Leary, “Chimica Analitica Strumentale”, Edises. |

4 | Spettroscopia Raman | Skoog, Leary, “Chimica Analitica Strumentale”, Edises. |

5 | Metodi elettrochimici | Skoog, Leary, “Chimica Analitica Strumentale”, Edises. |

6 | Statistica | Maria Garetto, "STATISTICA Lezioni ed esercizi". QUADERNI DIDATTICI del Dipartimento di Matematica. Università di Torino. |