System Suitability - Tip317

OBJECTIVE or GOAL

How to examin a System Suitability Challenge

ENVIRONMENT

• Empower
• Tip of the Week #317

PROCEDURE

Examine a System Suitability challenge. 

Challenge: To apply one set of System Suitability criteria to a peak in a blank and then apply a different set of criteria to the same peak in another sample. We will use the Acceptance Criteria Limits table in the Processing Method to accomplish this.

(NOTE: The Acceptance Criteria Limits are often used with the Method Validation Manager.)
 

Step 1
The Sample Set has a blank, which is a control sample, followed by standards and then another control sample (figure 1). 

Step 2
The amounts for the control samples and standards are entered into the Component Editor (figure 2).

Step 3
The peak field which we will evaluate is a simple peak Custom Field (figure 3).

Step 4
The System Suitability criteria for the peak in the blank is: the calculated value for the Custom Field must be greater than or equal to 100 (figure 4). 
We use the Acceptance Criteria Limits table in the following way, starting with the first row (be sure to first highlight the row for the peak in the Suitability Components table): 

• Field Name – click in the field and select the custom peak field from the list
• Left Side – you are essentially creating an equation. Click in this field and the Custom Field formula entry opens. 
  
  The left side is: 
  EQ(Label,"B")*STD_RCV+NEQ(Label,"B")*-1*50000  
  
  This works as follows and uses Boolean logic. If the label equals B (for the blank), then it returns a 1, and 1 multiplied by the value generated by the Custom Field returns the value generated by the Custom Field. If the label does not equal B, then it returns a 1. The negative 50000 returns a null so 1 multiplied by null returns an empty field.
• Operation – click in this field to select a mathematical operator, in this case, GTE for greater than or equal to
• Right Side – click in the field and the Custom Field formula entry opens. Enter the value
• Precision – enter the desired display precision
• Warning/Error – select Warning or Error
• % of Target – not applicable in this case
• Ignore Blank Values – selecting this field would instruct Empower to ignore blank values, i.e., if the Custom Field was not calculated
• Check Relative Limits – click in this field and select During Quantitation from the list

The system suitability for the peak in the other control sample is 95.5 +/- 2% which equals a range of 93.59 – 97.41. 

The left side in this case is:
EQ(Label,"C3")*STD_RCV+NEQ(Label,"C3")*-1*50000 

The same Boolean logic applies except in this case Empower is looking for the label C3 which is the label for the next control sample. The mathematical operator used in this case is RANGE since there is an acceptable range for the calculated value. Finally, we use the % of Target to set the range which is based on the entry in the Right Side field.

Step 5
A detailed view of the fields which “pop out” are displayed in figure 5. 
(NOTE: Precision, % of Target require entry of a value and Ignore Blank Values requires checking the box.)

Step 6
The result for the blank, which is the first control sample, is greater than 100 so it meets the criteria (figure 6). 

Step 7
The result for the first injection of the next control sample is 94.31, within the acceptable range so it meets the criteria (figure 7).

Step 8
The result for the second injection of the control sample is 93.283, below the lower limit of the acceptable range. Therefore, the peak name and value for the Custom Field are in bold, red, italicized font (figure 8).

ADDITIONAL INFORMATION

This can be done with either the Pro or QuickStart interface.