| N6-Benzylaminopurine (6-BA) was the first cytokinin of artificial synthesis。Its main ingredients are purine and some inorganic substances and it is the highest active in the cytokinin. N6-Benzylaminopurine as the main component of preservative agent and growth-promoter, has been on the application stage at home and abroad. Use as a growth-promoter, 6-BA was able to enhance seed germination, seedling growth and ultimately improve productivity, often used to promote the growth of bean sprouts, increase tobacco yields. 6-BA was also able to keep plant fresh by inhibiting plant chlorophyll, nucleic acid, protein degradation and respiration, etc, so 6-BA also as preservatives was used to keep fresh and store for a variety of green leafy vegetables (such as green pepper, cucumber, beans). Excessive intake 6-BA of the body through the food chain will stimulate the esophagus, gastric mucosa, cause these phenomenons including damage, nausea, vomiting and so on. N6-Benzylaminopurine (6-BA) was allowed as food additives in national standard GB 2760-1996 which gives the maximum allowed limit (0.01 g/kg) and maximum and allowed residues (0.20 mg/kg) of N6-Benzylaminopurine (6-BA). Excessive intake of the body through the food chain 6-BA will stimulate damage of the esophagus, gastric mucosa, such as nausea, vomiting and so on. At present, standard determination for food-grade 6-BA has not been established in the domestic and foreign. In order to ensure the quality and safety of food additives N6-Benzylaminopurine for import and export, safeguard the interests of consumers, it is necessary to develop appropriate quality determination standards. The standards can guide production related to business, improve generation technology and strengthen production management. They can explore the characteristics of manufacturing enterprises in China-related security plans and provide a reliable basis for ensuring inspection and quarantine of import and export food additives.In order to find an effective implementation of monitoring to ensure the N6-Benzylaminopurine quality and smooth progress of the work of import and export trade, establishing a rapid and accurate determination of (food grade) N6-Benzylaminopurine quality methods in the industries including biochemistry, agriculture, food industry and import and export has very important significance .In this paper, standard determination of the N6-Benzylaminopurine quality (content, impurities, etc.) is to fill a gap of quality testing methods (the standard method of preparation). The N6-Benzylaminopurine residue of the vegetables was determined by High Performance Liquid Chromatography and microwave-assisted extraction with the acidified methanol as extraction agent. This paper includes two parts:Part I: The standard method which determine content of N6-Benzylaminopurine (food grade) established by high performance liquid chromatography and ultraviolet spectrophotometry fills the gaps of the country. High performance liquid chromatography experiments measured the average content of 98.49%, S=0.20; UV spectrophotometry for the measured average concentration of 98.25%, S=0.14, throw F test and T test after that precision of high performance liquid chromatography and spectrophotometry was no significant difference between the two methods and had no system errors, or both methods can be used for food grade quality of 6-BA determination. According to China's actual conditions, food additives, standards quality of 6 BA defined as: content /%≥95.0.Part II: In the first part of the content, based on high performance liquid chromatography of N6-Benzylaminopurine vegetables residues, residues two extraction methods using 6-BA in vegetable samples, namely, microwave extraction and ultrasonic extraction, two extraction methods are discussed in the liquid-solid ratio, time and temperature on the 6-BA extraction yield. UE which samples extracted from mung bean sprouts 6-BA in experimental conditions residual liquid to solid ratio of 4:1, the extraction time was 30 min, the measured extraction yield was 0.3824μg/g, the RSDs were less than 1.9, good reproducibility, recoveries between 84.85 ~ 86.57%; MAE conditions of samples of mung bean sprouts 6-BA in experimental conditions residual liquid to solid ratio of 4:1, extraction time 10 min, extraction temperature 60℃, extraction yield was measured 0.6535μg/g, the RSDs were less than 3.8%, the analysis results were reproducible good recovery between 93.92% and 96.46%. Experimental results show: Microwave extraction method is more suitable for vegetables in the 6-BA extraction, sample handling in the vegetable has a good prospect. The results of two extraction methods showed that: Compared with ultrasonic extraction, microwave extraction has the time-consuming and less extraction yields advantages. In this paper, the microwave extraction-HPLC determination of 6-BA residues in vegetables in the amount of the detection limit 0.016 mg / kg (lower than the maximum allowable residue 0.20 mg / kg); recovery of method was 93.92 ~ 96.46%, RSD <5.7%, this method can be used for vegetables in the 6-BA residues.Standards determination of N6-Benzylaminopurine (food grade) quality (purity, impurities, etc.) for the development of this project is subject to the State General Administration of Quality Supervision, Inspection and Quarantine of the commission, in collaboration with the Jilin Entry-Exit Inspection and Quarantine Bureau, Jilin University for determination of 6-BA content. At present the research results of this project has been through The People's Republic of China General Administration of Quality Supervision, Inspection and Quarantine of the approval, this standard is awaiting for enactment.
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