摘要
为解决高纯石墨样品前处理中高温灰化耗时长(4~10h)的问题,提出了题示方法。取高纯石墨样品0.3000g,置于50mL聚丙烯样品管中,用15mL 10%(体积分数)王水(体积比为3∶1的盐酸-硝酸混合液)超声提取20min,提取时会有部分石墨漂浮于液面上,用注射器吸取样品管中部的提取液约3mL,过0.45μm水系滤膜后收集在样品管中,在灰化温度为900℃、原子化温度为2000℃等条件下采用石墨炉原子吸收光谱法进行测定。结果表明,超声提取缩短了样品处理时间(仅为20min)。铅元素的质量浓度在5~50μg·L^(-1)内与对应的吸光度呈线性关系,检出限(3s/k)为0.11mg·kg^(-1)。对同一样品分析7次,测定值的相对标准偏差为4.6%。按照标准加入法进行回收试验,回收率为91.0%~94.0%。
In order to solve the time-consuming problem of high-temperature ashing(4-10h)in the pretreatment of high purity graphite samples,a method mentioned by title was proposed.The high purity graphite sample(0.3000g)was taken and placed into a 50mL-polypropylene sample tube,and 15mL of 10%(volume fraction)aqua regia(a mixture of hydrochloric acid and nitric acid at a volume ratio of 3∶1)solution was added for ultrasonic extraction for 20min.Some graphite floated on the liquid surface in extraction process,so 3mL of the extraction solution was sucked from the middle of the sample tube with a syringe,and passed through 0.45μm water system filter membrane.The filtrate was collected into a sample tube and determined by graphite furnace atomic absorption spectrometry under the conditions such as ashing temperature at 900℃and atomization temperature at 2000℃.As shown by the results,ultrasonic extraction shortened the sample processing time(only 20min).Linear relationship between the corresponding absorbance and mass concentration of Pb was found in the range of 5-50μg·L^(-1),with detection limit(3s/k)of 0.11mg·kg^(-1).The same sample was analyzed 7times,with RSDs of the determined values of 4.6%.Test for recovery was made by standard addition method,giving results in the range of 91.0%-94.0%.
作者
魏洪敏
孟范胜
孔轶
张卉
炼晓璐
陈文化
强晓初
WEI Hongmin;MENG Fansheng;KONG Yi;ZHANG Hui;LIAN Xiaolu;CHEN Wenhua;QIANG Xiaochu(Beijing Haiguang Instrument Co.,Ltd.,Beijing101312,China)
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2023年第9期1028-1031,共4页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
关键词
高纯石墨
石墨炉原子吸收光谱法
超声提取
铅
high purity graphite
graphite furnace atomic absorption spectrometry
ultrasonic extraction
lead
