Maca Quality And Safety Assessment Research

Maca(Lepidium meyenii), is an Andean crop that grows at an altitude of 3500 m above. In 2011, the Chinese Ministry of Health approved Maca powder as a new resource food. In this paper, Maca as the research object, macamides and sildenafil were analysised by High performance liquid chromatography tandem mass spectrometry(HPLC-MS/MS). Inorganic elements in Maca were analysised by inductively coupled plasma mass spectrometry(ICP-MS). The thesis mainly focuses on the study as follows:Firstly, a HPLC-MS/MS method was established for the analysis of macamides in Maca. SB-C18 column was chosen as the separation column, and methanol and water as the mobile phase, The separation time was no more than seven minutes for separation of five macamides. A good linear relationship was in the range of 1～500μg/L, with the correlation coefficient higher than 0.9995. The limit of detection was 0.1～100 ng/L. The method had a good reproducibility and precision. It can be applied for the analysis of macamides in Maca.Secondly, a HPLC-MS/MS method was established for the analysis of Sildenafil in Maca products. The samples were separated on SB-C18 column and eluted using mobile phase of methanol(10 mmol/L ammonium acetate):water(10 mmol/L ammonium acetate). Precursors to product ion transitions of m/z 475.3>58.1 was chosen to quantify sildenafil, and m/z 475.3>282.9 was used as qualifying ion for sildenafil. The collision energies were 50 and 60 eV, respectively. The method was with good linearity in the concentration range of 0.2～20 μg/L, and the correlation coefficient was 0.9994. The method was accurate, reliable and highly sensitive, and it can be applied in the determination of sildenafil in Maca products.Finally, an ICP-MS method was established for the analysis of inorganic elements in Maca. Maca samples were processed by microwave digestion manner, and the conditions such as the acid specie used for digestion, digestion time, and evaporation temperature.etc had been optimized. Seventy-five kinds of inorganic elements in Maca had been semi-quantitative analysised by this method. Nineteen kinds of Inorganic elements were determinated. This method can be applied for the analysis of inorganic elements in Maca products.