Study Set Content:
employs light within the near-infrared region (roughly 750-2500 nm)
NIR
operates in the mid-infrared region (approximately 4000-400 cm-1).
FTIR
This difference in____ influences the kinds of samples that can be examined.
wavelength range
NIR and FTIR are ____ but rather serve as complementary techniques in analytical contexts.
not interchangeable
APPLICATIONS OF IR
• Used widely in chemical and physical analysis of laboratory and has a wide variety of applications during the manufacturing process.
• A qualitative fingerprint check for the identity of raw material used in manufacture and for identifying drugs.
• Used in synthetic chemistry as a preliminary check for compound identity, particularly for the presence or absence of a carbonyl group, which is difficult to check by any other method.
• Can be used to characterize samples in the solid and semi-solid states such as creams and tablets.
• Used as a fingerprint test for films, coatings and packaging plastics.
• Can be used to detect polymorphs of drugs (polymorphs are different crystal forms of a molecule that have different physical properties such as solubility and melting point, which may be important in the manufacturing process and bioavailability).
ASSAY THAT USES IR
• Assay of Meprobramate Tablets U.S.P.
• Assay of Trioxsalen, USP
• Assay 0f Acetazolamide, U.S.P
• Assay of Propoxyphene HCL Capsules U.S.P.
• Assay of Thiotepa for Injection N.F
• Assay of Diethyltoluamide NF
This technique is also used for the assay of other elements or metals such as potassium, sodium and calcium in blood and other biological samples.
FLAME SPECTROSCOPY
•FLAME SPECTROSCOPY Used in the assay o
f Lithium Carbonate, USP, an antidepressant agent.
Flame spectroscopic methods most frequently used for analysis are:
• Flame Emission spectrophotometry/ Atomic emission spectrophotometry
(AES) • Atomic absorption spectrophotometry (AAS)
can be both a qualitative analytical technique, in which the identity of a metal is revealed by the observed color (wavelength), and a quantitative analytical technique, in which the intensity of the light emitted from the analyte is a function of the number of atoms.
Atomic emission spectrometry
Atomic emission spectroscopy can be used to determine the identity, the structure and the environment of atoms by analyzing the (blank) emitted by them.
radiation
. ATOMIC EMISSION SPECTROPHOTOMETRY (AES) It has been employed to various fields, including
environmental analysis, clinical chemistry, and industrial setting.
Flame photometry provides a robust, cheap and selective method based on relatively simple instrumentation for quantitative analysis of some metals
STRENGTH
Only applicable to the determination of alkali and some alkaline earth metals.
LIMITATIONS
PRINCIPLE OF AES Atoms are (blank) so that they emit light, and the radiation emitted is (blank)
thermally excited, measured.
Flame
Monochromator
Variable slit
Anode
Photocell
