Uses Of IR spectroscopy

Question 1

USES of IR spec?

Answer 1

ID of drugs by matching specs
Functional group analysis
Detect polymorphs of drugs

Question 2

BP states some preparation and operational conditions must be same for sample and reference- T/F?

Answer 2

TRUE

Question 3

What should be used to calibrate fro similar resolution and accuracy?

Answer 3

Reference

Question 4

Which function group usually has the sharpest/ strongest peak?

Answer 4

C=O

Question 5

Which function group gives a broad peak?

Answer 5

O-H

Question 6

Which function groups are present in 2500-4000nm range

Answer 6

O-H
C-H
N-H

Question 7

Which func groups in 2000- 2500nm range?

Answer 7

C triple bond N

C triple bond. C

Question 8

Which func groups in range 1659- 1800?

Answer 8

C=O

Question 9

Which func groups in range 1550- 1650 ?

Answer 9

C=N

C=C

Question 10

Which func groups in range 650- 1550?

Answer 10

C-O
C-N
C-C

Question 11

C=O could be in the form of….?

Answer 11

ACID- COOH - broad as OH also present 
AMIDE- CONH2 if NH band also present 
ESTER- RCOOR- if C-O present 
ANHYDRIDE- RCO-O-COR- if 2 close c=o bends present 
ALDEHYDE- RVHO- if CH weak bands occur

Question 12

If C=O absent but OH present…?

Answer 12

Alcohol or phenol

Question 13

O-H and N-H are broad and almost in the same region- T/F?

Answer 13

TRUE

Question 14

Primary amine (RNH2) has how many peaks?

Answer 14

Broad with 2 sharp spikes

Question 15

Secondary amine has how many peaks?

Answer 15

Broad with one sharp spike

Question 16

The two types o instruments for IR specs?

Answer 16

1- dispersive instrument- old type

2- Fourier transform instrument- Modern

Question 17

Do both instruments produce different specs?

Answer 17

NO- same

Question 18

One advantage of Fourier transform instrument?

Answer 18

High data acquisition speed- many scans / min

Question 19

What can be inserted in the sample?

Answer 19

Solid 
Liquid 
Gas
Cream 
Film

Question 20

How to prepare a sample with a solid in it?

Answer 20

Use powdered sample - Apx 2mg + dry KBr - apx 200mg —> grind finely & compress
Disc formed
Lace in IR machine

Question 21

Can use any type of cell?

Answer 21

NO- use cells which are IR inactive in the interested range

Question 22

Which cells for an aq sample?

Answer 22

AgCl
ZnS
Diamond
Ge 
All non hygroscopic

Question 23

Which cells for non aq sample?

Answer 23

AKBr 
NaCl
CaF2 
CsI 
Not resistant to water—> dissolve

Question 24

Some applications of Near IR?

Answer 24

Quality control
Particle size
Blend uniformity
ID of polymorphic drugs

Question 25

PRO and CON of NIR

Answer 25

Pro- useful technique to determine properties of formulation
Cons- requires skilled persons