摘要
茶叶中氮和硫都是其主要生长必要的元素,其含量检测对茶树种植有重要指导意义。目前测定茶叶中总氮和总硫含量的方法需要使用酸溶或者碱熔对茶叶进行前处理,再通过检测设备检测其含量,过程繁琐且效率较低。文章建立了一种固体直接进样—元素分析仪同时测定茶叶中的总氮和总硫的分析方法。本研究进行了助溶剂用量、称样量、加标回收和精密度实验。实验表明,称样量为100 mg,无需加入助熔剂,以磺胺为系列标准品(总氮和总硫质量梯度分别为0~8.13 mg和0~9.31 mg),氮和硫的线性相关关系分别为0.999 99和0.999 98,氮和硫的加标回收率分别为98.0%~103.4%和96.8%~103.6%,氮和硫的相对标准偏差(n=6)分别为0.85%~1.70%和1.86%~2.73%,国家标准物质的测定结果在认定值的不确定度范围内。方法具有较好的线性和较广的线性范围,以及良好的精密度和较高的准确度。该方法操作简便和自动化程度高,适用于快速测定茶叶中的总氮和总硫含量。
Nitrogen and sulfur in tea are both essential elements for its growth,and the detection of their contents has a guiding significance for tea tree cultivation.At present,the methods for determining the total nitrogen and total sulfur content in tea require the pretreatment of tea by acid dissolution or alkali fusion,and then the content is determined by detection equipment,the process is cumbersome and inefficient.This paper establishes an analytical method for the simultaneous determination of total nitrogen and total sulfur in tea by solid direct injection-elemental analyzer.The study has conducted experiments on the dosage of cosolvent,sample weighing volume,spiked recovery and precision.The experiment result shows that when the sample weight is 100 mg and no flux is added,with sulfonamide as the series of standard substances(the mass gradients of total nitrogen and total sulfur are 0-8.13 mg and 0-9.31 mg respectively).The linear correlations between nitrogen and sulfur are 0.99999 and 0.99998,respectively.The spiked recovery rates of nitrogen and sulfur are 98.0%-103.4%and 96.8%-103.6%,respectively,and the relative standard deviations(n=6)of nitrogen and sulfur are 0.85%-1.70%and 1.86%-2.73%,respectively.The determination result of the national standard substances is within the uncertainty range of the recognized values.The method is characterized with the good linearity and wide linear range,as well as excellent precision and high accuracy.It is simple to operate and highly automated,and is suitable for the rapid determination of total nitrogen and total sulfur content in tea.
作者
黄环
谷娟平
王朝晖
黄全书
廖云安
李琴
HUANG Huan;GU Juanping;WANG Zhaohui;HUANG Quanshu;LIAO Yun-an;LI Qin(China Nonferrous Metal(Guilin)Geology and Mining Co.,Ltd.,Guilin 541004,Guangxi,China;Hezhou University,Hezhou 542800,Guangxi,China;QinZhou Quality and Safety Inspection of Agricultural Products Center,Qinzhou 535000,Guangxi,China;Qinzhou Inspection and Testing Center,Qinzhou 535000,Guangxi,China)
出处
《矿产与地质》
2025年第5期1125-1130,1146,共7页
Mineral Resources and Geology
基金
广西2025年“八桂之光”访学研修计划(科技人才专项)项目
贺州市校校合作研究项目(XXHZ202403)共同资助。
关键词
茶叶
总氮
总硫
元素分析仪
固体进样
同时测定
tea leaves
total nitrogen
total sulfur
elemental analyzer
solid sample injection
simultaneous determination
