level: Level 1 of INFRARED
Questions and Answers List
level questions: Level 1 of INFRARED
| Question | Answer |
|---|---|
| ELECTROMAGNETIC RADIATION ranging between __ is passed thru a sample and is absorbed by the bonds of the molecules causing them to __ | 1) 400 cm-1 and 4000 cm-1 (2500 and 20 000 nm) 2) stretch or bend |
| INFRA-RED SPECTROPHOTOMETRY applications: | 1 Qualitative fingerprint check for the identity of raw material 2 Preliminary check for compound identity (C=O) 3 Fingerprint (8.0 to 15um, fingerprint region) test for films, coating and packaging plastics, semi-solid samples 4 Use to detect polymorphs of drugs |
| INFRA-RED SPECTROPHOTOMETRY Strength: Limitations: | STRENGTH - Computer control of instrument means matching of the spectrum of a compound to its standard fingerprint Limitations: - Rarely used as a quantitative technique because of difficulty in sample preparation and complexity of spectra - Sample prep requires skill since sx handling can have effect on spectrum (esp Potassium bromide) |
| 1 color of the longest wavelength of VIS region (620 -780 nm) 2 Infra (latin) means | 1 Red 2 below |
| Some drugs assayed by IR region | 1 Acetazolamide 2 Propoxyphene 3 Thiotepa 4 Diethyltoluamide |
| is most often applied for ID purposes | the MEDIUM IR region (3 – 15 µm) |
| – identify pure organic and inorganic compounds (exemptions: O2, N2, Cl2) - considered LESS PRECISSE for quantitative analyses (few applications) IR spectra – greater complexity of spectra compared to UV VIS | IR spectrometry |
| greater complexity of spectra compared to UV VIS | IR spectra |
| To meet the required set in the compendium, the spectrum of __ under investigation and the corresponding __ are prepared and compared w/ one another. The __ must exhibit absorption maxima and minima only at the same λ as that of ref. std. | 1 medicinal agent 2 USP/NF ref. std. 3 spectrum of the medicinal agent |
| In IR-EMS, water cannot be used as solvent because: | 1. it ABSORBS most of IR radiation thereby obscuring absorption by the solute 2. water could DESTROY NaCl cells which hold the sample |