Objective To develop an ultra performance liquid chromatography-tandem mass spectrometry method for the determination of Nisin residues in various foods. Methods The samples were extracted with 0.1% formic acid solution+acetonitrile (80:20, V:V), delipid with n-hexane, eluted with 0.1% formic acid solution and acetonitrile as mobile phase gradient, and separated by ZORBAX Eclipse Plus C18 (100 mm×2.1 mm, 1.8 μm). Electrospray ion source and positive ion multi-reaction monitoring mode were used for detection, and matrix matching standard curve external standard method was used for quantification. Results The linear relationship between Nisin A and Nisin Z was good in the range of 0.5 to 50.0 μg/mL, and the correlation coefficient was greater than 0.995. The limits of detection and quantitation were 0.05 to 0.30 mg/kg and 0.15 to 1.00 mg/kg, respectively. The recoveries ranged from 88.8% to 106.2% and the relative standard deviations were 1.32% to 8.85% at the 3 added levels of 1.0, 5.0 and 200.0 mg/kg. Conclusion The established method is fast, efficient, repeatable, sensitive and accurate, and can be used for the determination of Nisin A and Nisin Z in batch food samples.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |