Why must we add NaOH to the borate buffer in the Kairos application kit? - WKB111767

ENVIRONMENT

• Kairos application
• neutralization

ANSWER

The addition brings urine to a higher (correct) pH for derivatization. The borate buffer used in Kairos is the one used with AccQ•Tag Ultra.

In the case of Kairos, the result of the addition of NaOH is twofold:

• Neutralization of the sulfosalicylic acid (in the internal standard) and HCl (in the calibrator standard)
• The extra NaOH results in an optimal pH for derivatization, which is at pH 9

Without adding NaOH to borate buffer, the reaction proceeds at lower pH, around pH 8, which results in poor derivatization and slightly lower areas for the derivatized amino acids.

ADDITIONAL INFORMATION