AOAC SPIFAN Nutrients ERP Method Reviews (September 7, 2019)

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Method Optimization : Reagent and calibration blanks were analysed in all analytical batches to ensure that responses corresponding to reagent blanks are clearly identified in the multi-analyte chromatogram. There were no significant interferences observed at the retention time of target amino acids. The calibration and reagent blanks were prepared and analyzed at frequent intervals in all analytical sequences to ensure the selectivity of the method.

• Performance Characteristics: Analytical Range :

SMPR : for all analytes 0.4 – 2500 mg/100g

In both methods, a linear dynamic ranges (LDR) of calibration for all the amino acids were established with five levels of working standards. Freshly prepared working standards were used in all the analytical sequence of the validation and the levels of all the amino acids in all matrices were well within the calibration range. The correlation coefficients (r2) of all the calibrations during the validation were not less than 0.999. LOQ: SMPR: ≤ 0.4 mg/100g

The LOQ for free amino acids are between 0.01 and 0.06

The LOQ for proteinogenic amino acids are on sample as is basis between 0,02 and 0.17 and for reconstituted basis are between 0.002 and 0.017.

Accuracy/Recovery: SMPR: for all analytes in mg/100g

0.4 – 5.0 ±10% 5.0 – 50 ±8% 50 – 2500 ±5%

NIST SRM 1849a and 1869: 97 to 110%

1- Method for determination of total proteinogenic amino acids and taurine Accuracy of the method was validated using standard reference materials (NIST SRM 1849a and 1869) and spiked recovery studies. The NIST reference materials (SRM 1849a and 1869) were analysed in duplicate on six separate days (12 independent results). 2- Method for determination of free aminoacids Accuracy of the method was validated using standard reference material (NIST SRM 1869) and spiked recovery studies. The NIST reference material (SRM 1869) was analysed on three separate sequences. The methionine results for the reference materials were within 90 to 110%.

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