Determination of Sulfonamides in Milk and Milk Powder

Method: SPE
Matrix: Milk
Application No.: 101728
Columns: ProElut PXC 200 mg / 6 mL 30/pk
Cat No.: 68212
Sample Pretreatment: 1. Sample preparation
To 15 mL milk (or 3 g milk powder in 15 mL H2O), add 15 mL acetonitrile, vortex for 2 min, centrifuge at 6,000 rpm for 5 min, transfer 20 mL supernatant to another centrifuge tube, and add 15 mL n-hexane, vortex for 2 min, centrifuge at 6,000 rpm for 2 min, then discard the n-hexane. Repeat 15 mL n-hexane extraction. Add 15 mL ethyl acetate to the lower layer, vortex for 2 min, centrifuge at 6,000 rpm for 2 min, and collect supernatant. Repeat 15 mL ethyl acetate extraction, and combine supernatants. Vacuum evaporate the ethyl acetate layer to near dry at 30 ºC, reconstitute with 10 mL 2% phosphoric acid.
2. Sample purification
ProElut™ PXC 200 mg / 6 mL (Cat#68212 )
Condition: 6 mL MeOH / 6 mL H2O
Load: Add sample
Wash 1: 6 mL H2O
Wash 2: 6 mL MeOH
Elute: 6 mL MeOH (5 % NH4OH)
Reconstitute: Vacuum evaporation at 30 ºC, reconstitute to 1 mL with mobile phase
Conditions: HPLC method
Column: Inspire™ 5 µm C18, 250 x 4.6 mm (Cat#81006)
Mobile Phase: A: MeCN, B: 2 % CH3 COOH in H2O
Flow Rate: 1.0 mL/min
Temperature: 35 ºC
Detection: UV 270 nm
Injection Volume: 20 µL
Author: Dikma Technologies Inc.
Keyword: Sulfonamides, Milk, Milk Powder, SPE, PXC