Chapter 5 Examining Spectrum Data

Type of Data

Suggested

 

Description

Method

 

 

 

 

 

 

 

High-resolution data

Noise

Specify the number of standard deviations of

 

Removal

noise to remove. The software automatically

 

(NR)

calculates the average white noise for all

 

 

frequencies across the spectrum, then

 

(Does not

removes the specified number of standard

 

deviations of noise.

 

affect peak

 

This method slightly affects peak intensity, and

 

resolution.)

 

removes peaks with a signal-to-noise ratio less

 

 

 

 

than the specified standard deviation.

 

 

In general:

 

 

 

If you set

% White Noise

 

 

Std Dev to:

removed is:

 

 

1

68

 

 

2

95

 

 

3

99

 

 

If applying Noise Removal with a certain Std

 

 

Dev does not yield the necessary noise

 

 

removal, return to the original trace (see

 

 

“Returning to the original spectrum” on

 

 

page 5-3)and apply Noise Removal again with

 

 

a higher Std Dev setting. Applying Noise

 

 

Removal more than one time with the same

 

 

Std Dev setting does not improve noise

 

 

removal.

 

 

 

 

 

4.Click OK.

5

The trace is displayed with an RSM, NF, NR or SM trace label.

5. To return to the original trace, see “Returning to the original spectrum” on page 5-3.

5-44 Applied Biosystems