Residues of malachite green (MG) were extracted from homogenized animal tissues with a mixture of McIlvaine buffer (pH 3.0)–acetonitrile, and purified over an aromatic sulfonic acid solid-phase extraction column followed by ... Residues of malachite green (MG) were extracted from homogenized animal tissues with a mixture of McIlvaine buffer
(pH 3.0)–acetonitrile, and purified over an aromatic sulfonic acid solid-phase extraction column followed by HPLC or LC–ESI-MS–MS analysis. Ascorbic acid and N,N,N9,N9-tetramethyl-1,4-phenylenediamine dihydrochloride were added to reduce de-methylation of the dye. Responses were recorded at 620 nm (HPLC) or by multiple-reaction-monitoring (LC–MS–MS) after post-column oxidation using PbO2 . MG and its primary metabolite leuco-malachite green (LMG) were successfully determined at 2.5–2000 mg / kg in catfish, eel, rainbow trout, salmon, tropical prawns and turbot, with a limit of detection at 1 mg / kg (HPLC) and 0.2 mg / kg (LC–MS–MS) for both MG and LMG. Recoveries for LMG were between 86±15% (prawn) and 105±14% (eel). Freeze–thawing cycles, and storage at 4°C and -20°C affected the recovery of both MG and LMG. Analyses of eel, trout and (processed) salmon field samples collected at local retailers, fish-market and -shops demonstrated trace levels of MG-residues.
A McIlvaine solution at pH 3.0 was prepared by mixing 18.9 ml 0.2 M sodium hydrogen phosphate and 81.1 ml 0.1 M citric acid, whereas these volumes were 62.5 and 37.5 ml, respectively, to obtain a McIlvaine solution at pH 6.0. The SPE-eluent was prepared just before use and consisted of a mixture of 2.5 ml 25% (m/v) ammonium hydroxide, 2.5 ml 1.0 mg/ml methanolic ascorbic acid and 45 ml methanol. The sample-solvent was composed, just before use, from 2.5 ml 1.0 mg/ml methanolic ascorbic acid, 20 ml 50 mM sodium perchlorate containing 25 mM sodium acetate and 25 mM 1-pentanesulfonic acid adjusted to pH 4.0 with acetic acid, and 27.5 ml acetonitrile. Chemicals and solutions containing the dyes were protected from light.
Fish were bought at the fish market and local stores. Blank trout were collected from aquaria at
Utrecht University (The Netherlands). Tropical prawns were collected by the Dutch Inspectorate for Health Protection and Veterinary Public Health.
残滓绿沸铜绿色(MG)从与McIlvaine缓冲混合物的均匀的动物组织被提取了
(酸碱度3.0) -乙腈和净化在一个芳香磺酸固体阶段提取专栏被HPLC跟随了或LC-ESI-MS-MS分析。 抗坏血酸和N, N, N9, N9四甲基1,4苯二胺二氢氚化物增加减少染料的de甲基化。 反应记录在620毫微米(高性能液体色谱)或由多反应监视(LC-MS-MS)使用PbO2,在岗位专栏氧化作用以后。 MG和它的主要代谢产物leuco绿沸铜绿色(LMG)顺利地被确定了在鲶鱼、鳗鱼、虹鳟、三文鱼、热带大虾和比目鱼的2.5-2000 mg/kg,与检测极限在1 mg/kg (高性能液体色谱)和0.2 mg/kg (LC-MS-MS)的MG和LMG的。 LMG的补救在86±15% (大虾)和105±14% (鳗鱼)之间。 冷冻解冻在4°C和-20°C的周期和存贮影响了MG和LMG补救。 对鳗鱼、鳟鱼和(处理)三文鱼领域样品的分析收集了在地方零售商,鱼市场和-商店MG残滓的被展示的跟踪级别。
在酸碱度3.0的一种McIlvaine解答通过混合18.9 ml 0.2 M钠氢磷酸盐和81.1 ml准备0.1 M柠檬酸,而这些容量分别为62.5和37.5 ml,获得McIlvaine解答在酸碱度6.0。 SPE洗提液在用途之前准备了并且包括了2.5 ml 25% (m/v)氢氧化铵, 2.5 ml 1.0 mg/ml methanolic抗坏血酸和45 ml混合物甲醇。 样品溶剂在用途之前组成了,从2.5 ml 1.0 mg/ml methanolic抗坏血酸, 20 ml 50 mM包含25 mM钠醋酸盐和25 mM的钠高氯酸盐对与乙酸的酸碱度被调整的1-pentanesulfonic酸4.0和27.5 ml乙腈。 包含染料的化学制品和解答被保护了免受光。
鱼在鱼市和本机商店被买了。 空白的鳟鱼从水族馆收集了在
乌得勒支大学(荷兰)。 热带大虾由卫生防护和兽医公共卫生的荷兰检查团收集。
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