Determination of maleic hydrazide residue in tobacco and tobacco products using high performance liquid chromatography
Maleic hydrazide has been used as a growth regulator for grass and tobacco and as a sprout suppressant for onions and potatoes. Its popularity for growth regulator of tobacco has increased over the last few years. Maleic hydrazide has a systemic mode of action, translocating to the tubers by way of the vascular system, after being applied to the plant's leaves. According to the CORESTA, the maximum residue level (MRL) of maleic hydrazide permitted in tobacco and tobacco products is 80mg/kg. The literature contains several methods for the extraction of maleic hydrazide from a range of commodities, including garlic, onions and potatoes. However, few of them are fully appropriate for the extraction of maleic hydrazide from tobacco and tobacco products. So a method for the determination of maleic hydrazide in tobacco and tobacco products was established by high performance liquid chromatography. Tobacco samples were separated with Varian Microsorb-MV 100-5 C18 column(250*4.6mm) using 0.1M acetic acid as mobile phase, after extracted by 4mol/L hydrochloric acid (in which a mixture of free and bound maleic hydrazide is extracted), and cleaned up by C18 solid-phase cartridge. It was quantified by external standards method and determined at UV 313 nm. Results showed that the linear range for the maleic hydrazide was 0.1 µg /ml - 100µg /ml and the limit of quantify was 1 µg /g. A blank tobacco sample was spiked at 8, 80, 160µg/g for maleic hydrazide, and the average recoveries ranged from 94.18% to 96.32%, with the relative standard deviations(RSD) below 13.60%(n=6). This method could be used for determine the maleic hydrazide in tobacco and tobacco products.