Methylene Blue分光光度法与高效液相色谱法测定食品中糖精钠含量的比较研究

Comparison of Methylene Blue spectrophotometry and HPLC on quantitative determination of Saccharin in Food Products

目的探讨和比较Methylene Blue分光光度法和高效液相色谱法测定食品中糖精钠含量的可靠性。方法Methylene Blue分光光度法以糖精钠磺酰基团与亚甲蓝和乙酸铜定量生成的蓝色络合物为定性指标，在656nm处进行比色测其吸光度。高效液相色谱法以：Luna5u—C18柱（250nm×4．6nm，10μm）为分析柱，以甲醇＋1．54g／L醋酸铵溶液=15＋85为流动相，流速1．0mL／min，检测波长为230nm。结果Methylene Blue分光光度法，糖精钠在0～350μg／mL范围内线性关系良好（r=0．9976），最低检出限为0．006g／mL，加标回收率为99．651％～101．957％，变异系数为0．150％-0．660％。高效液相色谱法，糖精钠浓度为1—200μg／mL时，峰面积与浓度呈良好的线性关系（r=0．9997），最低检出限为0．004g／mE，加标回收率为99．908％-101．007％，变异系数为0．050％～0．430％。配对t检验统计结果表明Methylene Blue分光光度法和高效液相色谱法检测样品中糖精钠的含量差异无统计学意义。结论Methylene Blue分光光度法和高效液相色谱法均能达到较好的准确度和精密度，可根据各自的实际条件选用不同的测定方法。

Objective To explore and compare the reliability of the quantitative determination of total saccharin from commercial food products using Methylene Blue spectrophotometry and HPLCo Methods Methylene Blue spectrophotometry is based on the reaction of sulfonyl of the saccharin and Methylene blue and its product of a blue compound （ max = 656 } which can be extracted by 1,2 - dichloroethane and determinated by colorimetfic. HPLC was performed on a Luna 5 u-C18 analytical column （250 mm × 4.6 mm, 10m ） was used with ammonium acetate （ 0. 02 mol/L, pH ： 6.5 ）/methanol （ 85 ： 15 ） as mobile phase （ 1 mL/min ） and the detector wave was at 23 Onmo Results The linear range of saccharin was 0 - 350 μg · mL^ -1 for Methylene Blue spectrophotometry （ r = 0. 997 6 ）. The detection limit was 0.006 g · mL^ -1, recoveries were ranging from99. 651% to 101. 957 % ,standard deviations were ranging from （ 0. 150 - 0.660 ） %. For HPLC analysis, saccharin had good linearity in the ranges of 1 - 200 μg· mL^ -1（ r = 0.999 7 ）, the detection limit was 0. 004 g · mL^ -1 , recoveries were ranging from 99. 908 % to 101. 007 % ,standard deviations were ranging from （0.050 - 0.430 ） %. The results of paired t test showed that the determination of saccharin from the two methods have no significant difference. Conclusion The two methods of Methylene Blue spectrophotometry and HPLC were both proved to be accurate and satisfied. We can choose the better method according to our practical needs.