Determination of Melamine in Milk and Dairy Products

Method: SPE
Matrix: Milk
Application No.: 101723
Columns: ProElut PXC 60 mg / 3 mL 50/pk
Cat No.: 68203
Sample Pretreatment: 1. Sample preparation
1.1. Milk and milk powder
Dilute milk (2 mL) or milk powder (1 g) with 5 mL of trichloroacetic acid aqueous solution (10 g/L) in a 15 mL centrifuge tube, add 0.5 mL lead acetate aqueous solution (22 g/L) and 2 mL chloroform, vortex and centrifuge 2 min at 3,000 rpm, collect supernatant, add 5 mL trichloroacetic acid aqueous solution (10 g/L) to residue, vortex and centrifuge 2 min at 3,000 rpm, collect and combine supernatants.
1.2. Cream candy and cookies
Grind 1 g sample with sand into powder in a mortar, add powder to a 50 mL centrifuge tube, rinse the mortar with 15 mL of trichloroacetic acid aqueous solution (10 g/L), transfer solution to centrifuge tube then shake, add 1 mL lead acetate aqueous solution (22 g/L) and 5 mL chloroform, vortex and centrifuge 2 min at 3,000 rpm, collect supernatant, add 15 mL trichloroacetic acid aqueous solution (10 g/L) to residue, vortex and centrifuge 2 min at 3,000 rpm, collect and combine supernatants.
2. Sample purification
ProElut™ PXC 60 mg / 3mL (Cat#68203)
Condition: 3 mL MeOH / 3 mL H2O
Load*: supernatant
Wash 1: 3 mL deionized water
Wash 2: 3 mL MeOH
Elute: 3 mL 5 % NH4OH in MeOH
Reconstitute: Evaporate at 50 ºC by N2, reconstitute to 1 mL with MeOH:H2O (20:80, V / V) solution*12 mL reservoir (Cat#4810) and adaptor (Cat#4803) is available for large volume sample
Conditions: HPLC method
Column: Inspire™ 5 µm C18, 150 x 4.6 mm (Cat#81001)
Mobile Phase : Buffer:MeCN = 92:8
Flow Rate: 1.0 mL/min
Temperature: 30 ºC
Detection: UV 240 nm
Injection Volume: 20 µL
Buffer: dilute 2.02 g sodium 1-heptanesulfonate and 2.10 g citric acid with water to total volume 1,000 mL
Author: Dikma Technologies Inc.
Keyword: Melamine, Dairy Products, Milk, SPE, PXC, Inspire