Atomic Spectra Week 3 Lab S117 Fall 2011

Overview Post-Lab: MS – Modern Mass Spectrometry techniques – Analysis of Proteins – Informatics Pre-Lab: Atomic Spectra – Theory – Application of atomic spectroscopy – Practical aspects

Modern Mass Spectrometry

Double focusing instruments GC-MS MALDI-TOF Electrospray

Identification of Proteins Purified Protein Mix of Peptides Trypsin Digest Mass Data of mixture Mass Spec MS Library Identity of Protein ASRLVMKQQKD ASR LVMK QQK D Example 1 Example 2 ASRLVKMQKQD

Informatics Applied information technology The data is thereyou just have to know how to organize and find it! Genomics Proteomics

Atomic Spectroscopy Problem of line spectra Empirical series of numbers – Predicted by equations No theoretical understanding of equations Bohr model

Bohr Model

Applications of Atomic Spectra Elemental fingerprint In theory, just have to get atoms apart and pumped full of energythen measure the fingerprint of line spectrum emitted or absorbed Practice is tougher than principle! Bunsen and Kirchhoff would be proud.

This Week in Lab Collect electric emission data from 6 elements/compounds Collect flame emission data from 6 ions Use data to determine difference in energy levels and identify two unknowns

Considerations Discharge lamps: HIGH VOLTAGE – Do not touch unless unplugged – Do not stare at light – 30s on/30s off Use gloves with salts Turn off Bunsen burners when not in use Use correct Nichrome wires