Cope-LLG Catalogue 2018

1449 14. Chromatography Sample preparation/SPE GENERAL CATALOGUE EDITION 20 E & OE. SPE phases for food analysis QuEChERS method and pre-mixes Within a few years after its devleopment by Anastassiades et al. the QuEChERS method has gained a leading position for determination of pesticide residues in food by GC-MS or LC-MS allowing rapid and cheap clean-up of strong matrix- contaminated samples. Standard clean-up of food samples 10 g sample are homogenised with 10 ml acetonitrile. After adding the internal standard the sample is shaken with 4 g MgSO 4 and 1 g NaCI and afterwards centrifuged. 1 ml of the supernantant is spiked with 25 mg CHROMABOND ® Diamino and 150 mg MgSO 4 and shaken again. After centrifugation the supernatant is injected into the GC/MS. For optimising the extraction of pH-dependent compounds, for minimising decomposition of sensitive substances and for broadending the matrix spectrum, different modifications of the QuEChERS method have been elaborated. 1 1 Extraction mixtures for sample preparation for determination of pesticides in food samples. MACHEREY-NAGEL offers a number of individually weighed and pre-mixed buffers and extraction mixtures, specially composed for different sample matrices. Mix I and Mix II are extraction mixtures, Mix III to Mix VI are clean-up mixtures. The food samples will be extracted with either Mix I or Mix II. Afterwards they will be purified with one of the following mixtures: - Mix III (samples with low fat content; e.g. apples, strawberries), - Mix IV (moderate content of chlorophyll and carotinoids; e. g. carrots, lettuce), - Mix V (high content of chlorophyll and carotinoids; e. g. bell peppers, spinach), - Mix VI (high fat content; e. g. avocados). Every mix is prepacked in a 15 ml centrifuge tube. Pack of 50 pieces. MACHEREY-NAGEL Description Capacity Composition PK Cat. No. ml Mix I Citrat-Extraction-Mix Mix I Citrat-Extraction-Mix Mix II Acetat-Extraction-Mix Mix III Diamino Clean-up Mix Mix IV Diamino/Carbon Clean-up Mix Mix V Diamino/Carbon Clean-up Mix Mix VI Diamino/C 18 ec Clean-up Mix 15 15 15 15 15 15 15 4 g MgSO 4 , 1 g NaCl, 0.5 g Na 2 H citrate 1.5 H 2 O, 1 g Na 3 citrate, 2 H 2 O 0.8 g MgSO 4 , 0.2 g NaCI, 0.1 g Na 2 H-citrate 1.5 H 2 O, 0.2 g Na 3 -citrate 6 g MgSO 4 , 1.5 g Na acetate 0.15 g CHROMABOND ® Diamino with 0.9 g MgSO 4 0.15 g CHROMABOND ® Diamino with 0.9 g MgSO 4 and 15 mg Carbon 0.15 g CHROMABOND ® Diamino with 0.9 g MgSO 4 and 45 mg Carbon 0.15 g CHROMABOND ® Diamino with 0.9 g MgSO 4 and 150 mg C 18 ec 50 50 50 50 50 50 50 4.003 824 7.971 498 4.003 825 4.003 826 4.003 827 4.003 829 4.003 828 Accessories CHROMABOND ® QuEchERS Empty PP centrifuge tube with screw cap, 50 ml, without QuEchERS mixtures. 3 MACHEREY-NAGEL Type PK Cat. No. 50ml PP-centrifuge tube with crew cap 50 4.003 552 3 For more centrifuge tubes, please see page 679. 2 2 CHROMABOND ® QuEChERS extraction buffer mixes/clean-up mixes