Preprocessing

method

Cefuroxime sodium

Cefotaxime sodium

Ceftriaxone sodium

Within -class variance

(I)

Between -class

variance

(O)

O/I

Within -class variance

(I)

Between -class

variance

(O)

O/I

Within -class variance(I)

Between -class

variance

(O)

O/I

VN

0.381

2.700

7.1

0.471

2.700

5.7

0.193

4.596

23.8

FD

0.021

0.325

15.5

0.054

0.228

4.2

0.011

0.228

20.7

FD+VN

0.668

21.380

32.0

3.457

16.278

4.7

0.214

16.278

76.1

SD

0.002

0.032

16

0.005

0.020

4.0

0.001

0.020

20.0

SD+VN

0.794

23.753

29.9

4.008

19.254

4.8

0.306

19.254

62.9

Table 2: Ability of spectral preprocessing methods to remove the effect of glass vials on NIR spectra of drug samples.