Enhanced methodology for porting ion chromatography retention data.

Area of Science:

• Analytical Chemistry
• Chromatography

Background:

• Column variability necessitates recalibration of ion chromatography (IC) retention time databases.
• Existing porting methods, used in commercial software like Thermo Fisher Scientific's "Virtual Column", have limitations in prediction accuracy.
• Current porting relies on two analytes and three isocratic separations, sometimes leading to errors.

Purpose of the Study:

• To improve the accuracy and robustness of the porting methodology for IC retention time prediction.
• To address observed errors in retention prediction with the existing porting approach.
• To validate an updated porting method across different IC columns and conditions.

Main Methods:

• Modified the porting methodology by increasing the number of representative analyte ions from two to six (chloride, bromide, iodide, perchlorate, sulfate, thiosulfate).
• Applied the updated porting methodology to three Thermo Fisher Scientific columns (AS20, AS19, AS11HC).
• Evaluated retention prediction accuracy for ten test anions under three eluent conditions, including on a used column.

Main Results:

• The new porting methodology achieved average errors of less than 1.5% in retention times for ten test anions across three columns and eluent conditions.
• Demonstrated acceptable accuracy on a used column with altered ion-exchange capacity.
• The enhanced method provides more accurate and robust retention predictions compared to the previous approach.

Conclusions:

• The revised porting methodology using six analytes significantly enhances the accuracy and reliability of ion chromatography retention time prediction.
• This improved method is effective across a range of columns and conditions, including those with degraded performance.
• The updated approach offers a more robust solution for maintaining and utilizing IC retention time databases.