硒粉催化-连续流动分析法测定烟叶中总氮的含量
Determination of Total Nitrogen in Tobacco by Selenium Powder Catalysis-Continuous Flow Analysis
张志灵 1陈庆文 1林海滨 1林祖斌 1林隆1
作者信息
- 1. 福建省烟草质量监督检测站,福州 350111
- 折叠
摘要
取约 0.2 g烟末样品置于消化管中,加入 3 mL物质的量比为 0.25%的硒/硫酸混合消化储备溶液,混匀,加入 3.0 mL的 30%(质量分数)过氧化氢溶液,升温至 330℃保持 1.0 h,冷却后用蒸馏水定容至 75 mL,在连续流动分析仪上于 660 nm处比色测定总氮含量.结果表明,总氮的质量浓度在 0.020 5～0.205 0 g·L-1 内与其对应的吸光度呈线性关系,检出限(3s)为 2.364 mg·L-1.方法用于分析实验室控制样品,测定值与标称值一致.日内平行测定实验室控制样品 6 次,日间平行测定 5 次,测定值的相对标准偏差均小于 3.0%.按照标准加入法进行回收试验,回收率为95.1%～102%.
Abstract
About 0.2 g of the tobacco powder sample was taken into digestive tube,then 3 mL of mixed digestion reserve solution of selenium powder and sulfuric acid at mole ratio of 0.25%was added.After blending,3.0 mL of 30%(mass fraction)hydrogen peroxide was added.The mixture was heated to 330℃,keeping for 1.0 h.After cooling,the obtained solution was made its volume up to 75 mL by distilled water.Total nitrogen was determined by continuous flow analyzer at 600 nm.As shown by the results,linear relationship between the corresponding absorbance and mass concentration of total nitrogen was found in the range of 0.020 5-0.205 0 g·L-1,with detection limit(3s)of 2.364 mg·L-1.This method was applied for determination of laboratory control samples,and the determined values were consistent with the nominal values.Laboratory control sample was determined 6 times in parallel for intraday and 5 timies for interday by this method,with RSDs of the determined values less than 3.0%.Test for recovery was made by standard addition method,giving results in the range of 95.1%-102%.
关键词
硒粉/总氮/烟草/测定Key words
selenium powder/total nitrogen/tobacco/determination引用本文复制引用
基金项目
福建省烟草公司科技项目(2021350000240006)
出版年
2024
NETL
NSTL
万方数据