Chen Yu

Mass spectrometry: Ionize molecules and separate by m/z. Molecular ion M+ gives molecular weight. Isotope patterns help (Cl: 3:1 M/M+2, Br: 1:1). HRMS gives mass to 4 decimal places for formula ID.

IR spectroscopy: Molecular vibrations absorb IR. Key bands: O-H ~3300, C=O ~1700, C-O ~1100 cm-1. Fingerprint region (1500-400) is unique per molecule. Used for functional group ID.

1H NMR basics: Chemical shift (δ) reflects electronic environment. TMS at 0 ppm as reference. 1H range: 0-12 ppm. Integration = proton count. Splitting follows n+1 rule (neighboring protons).