1. Quantification of Melamine in Milk and Dairy Products by Liquid Chromatography after a Simple Sample Clean-Up Procedure.
- Author
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El‐sheikh, Amjad H., Al‐degs, Yahya S., Abu‐Wardeh, Asma'a H., and Al‐ghouti, Mohammad A.
- Subjects
MELAMINE ,COMPOSITION of milk ,COMPOSITION of dairy products ,LIQUID chromatography ,EXTRACTION (Chemistry) - Abstract
In this work, a simple procedure of melamine determination in dairy products is reported. This is based first on melamine extraction from dairy products by 1% acetic acid, sonication, centrifugation and filtration by 0.45 µm filter. The proposed method has a low detection limit (0.50 mg kg
−1 ), high accuracy (%recovery 98.9%), high precision (%RSD range 1.6-2.5%), high calibration sensitivity (19,335 (mg l−1 )−1 ), and a wide dynamic range (1.0-50.0 mg l−1 ). Melamine was accurately quantified in spiked powdered milk, infant powder milk, full-fat liquid milk, fat-free liquid milk, local yoghurt, and local soft cheese (spiking levels 0.5, 50, and 1000 mg kg−1 ). The samples have variable amounts of fat (0-29%) and protein (3-23%) indicating the wide applicability of the proposed method. The %recoveries with %RSD were 78.2-103.6(2.5), 92.7-98.8(4.7), 79.3-101.5(3.8), 86.3-101.0(2.6), 78.0-89.2 (8.3), and 91.8-103.8(3.2) for soft cheese, yoghurt, powdered milk, infant powder, full-fat liquid milk, fat-free liquid milk, respectively. Practical Applications A simple and accurate analytical method was proposed for quick melamine detection and quantification in milk and dairy products having variable amounts of fat (0-29%) and protein (3-23%) with minimal sample clean up. The method is mainly based on melamine extraction by 1% acetic acid, sonication, centrifugation for 4.0 min, and filtration by 0.45 μm cellulose filter. The method could detect melamine down to 0.50 mg kg−1 with acceptable accuracy and precision (2.5 mg kg−1 is the upper limit of melamine in milk and dairy products). The proposed method was found effective for melamine quantification at three variable spiked levels (0.5, 10, and 1000 mg kg−1 ) in local soft cheese, local yoghurt, powdered milk, infant powder, full-fat liquid milk, fat-free liquid milk with %recoveries (%RSD) of 78.2-103.6 (2.5), 92.7-98.8 (4.7), 79.3-101.5 (3.8), 86.3-101.0 (2.6), 78.0-89.2 (8.3), and 91.8-103.8(3.2), respectively. [ABSTRACT FROM AUTHOR]- Published
- 2017
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