顶空-气相色谱法与氢气微电极法用于富氢水中氢气含量的检测

Determination of Hydrogen Concentration in Hydrogen-rich Water by Headspace Gas Chromatography and Hydrogen Microelectrode

氢气含量为富氢水的关键指标之一,但目前尚无标准检测方法。本文将超饱和富氢水稀释后采用顶空-气相色谱法与氢气微电极法测定了氢气含量,对检测方法进行了条件优化、方法学评价,并对市售富氢水产品进行了氢气含量检测。结果显示,顶空-气相色谱法优化后的顶空进样平衡温度为70℃、平衡时间为20 min。在0~1.61 mg/L氢气含量范围内决定系数(R^(2))为0.9976,在0.161、0.805、1.449 mg/L添加水平,回收率分别为104.90%、102.22%和97.78%,相对标准偏差(RSD)分别为3.87%、2.29%和1.69%。氢气微电极法在0~1.61 mg/L氢气含量范围内R^(2)为0.9978,在0.161、0.805、1.449 mg/L添加水平,回收率分别为96.75%、95.78%和98.00%,RSD分别为1.84%、0.98%和2.80%。对7种市售罐装富氢水的检测发现,不同产品中氢气含量相差较大,从0.8~6.2 mg/L不等,但均达到现有团体标准的要求。开盖后超饱和富氢水中氢气存留量在30 min内降低约10%,6 h内降低约50%。本研究建立了富氢水中氢气含量的检测方法,顶空-气相色谱法与氢气微电极法均可用于实际样品的测定。

The hydrogen concentration is one of the key indicators of hydrogen-rich water,but there is no standard detection method at present.In this paper,the concentration of hydrogen in hydrogen-rich water was determined by headspace gas chromatography and hydrogen microelectrode followed by sample dilution.The detection method was optimized,the methodological evaluations were performed,and the hydrogen concentrations of hydrogen-rich water products were tested.Results showed that for headspace gas chromatography method,the optimized headspace sampling equilibrium temperature was 70℃ and the time was 20 min.The determination coefficient(R^(2))was 0.9976 in the range of 0~1.61 mg/L hydrogen content.The recoveries were 104.90%,102.22%,97.78%,and the relative standard deviations(RSD)were 3.87%,2.29%,1.69% at the spiked levels of 0.161,0.805 and 1.449 mg/L.For hydrogen microelectrode method,the R^(2) was 0.9978 in the range of 0~1.61 mg/L hydrogen content.The recoveries were 96.75%,95.78%,98.00%,and the RSD were 1.84%,0.98%,2.80% at the spiked levels of 0.161,0.805 and 1.449 mg/L.For the detection of seven commercial hydrogen-rich water products,it showed that hydrogen content varies greatly,ranging from 0.8~6.2 mg/L,although they all met the requirements of the existing group standard.The hydrogen concentration decreased by 10% in 30 min and 50% in 6 h after the cover was opened.The present study would develop the methods for hydrogen concentration detection in hydrogen-rich water,and both of the headspace gas chromatography and hydrogen microelectrode methods were reliable and can be used in actual samples.