AOAC SPIFAN Nutrients ERP-Final Review (Jan. 2019)

2015.10 (Jan. 2019) Carn-07 MLT Report FOR ERP USE ONLY DO NOT DISTRIBUTE

corresponding internal standard peak areas to obtain relative analyte responses (normalized to IS). Relative responses of each analyte in the calibration standards are plotted on the y-axis against their corresponding concentrations on the x-axis to generate calibration curves with linear fit and 1/x 2 weighting for all compounds. Analyte concentrations in the sample extracts are derived from the calibration curves and their concentrations in the samples are determined using the following equation:

C x V x D W x 1000

= mg/kg

Where: C

= = = =

Analyte concentration in sample (ng/mL).

V D

Final volume (mL). Dilution (mL/mL). Sample weight (g).

W

1000 =

Conversion from ng/g into mg/kg

Table 2015.10A. Preparation of working standard solutions

MS grade water (mL) 6.00

Concentration (µg/mL) Extracted (ng/mL)

Source solution ID Stock solutions Stock solutions Stock solutions

Source concentration (mg/mL)

Source volume (mL)

Final volume

Standard Solution

STD6

25.0

2.00 each 1.60 each 0.800 each 1.00 0.400 0.200

10.0

5000

STD5

25.0

6.80

10.0

4000

STD4

25.0

8.40

10.0

2000

STD3 STD2 STD1

STD6 STD3 STD3

5.00 0.500 0.500

9.00 9.60 9.80

10.0 10.0 10.0

500

20 10

Note: Alternate weights or volumes may be used to scale these preparations

Table 2015.10B. HPLC parameters

Column:

Zorbax 300-SCX, 3.0 x 50 mm, 5 µm (Agilent, Santa Clara, CA) 5 mM Ammonium Formate in water:ACN (50:50, v:v) with 0.2% Formic Acid 30 mM Ammonium Formate in water:ACN (50:50, v:v) with 0.2% Formic Acid

Mobile phase A:

Mobile phase B:

Injection Volume:

5-10 μL

Run Time:

4.2 minutes

Gradient program:

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