A new ion chromatography method has been developed to study graphene oxide (GO) reduction by monitoring hydrazine concentration in the GO suspension. The method is based on ion chromatographic separation of hydrazine (from excess ammonia) and its selective determination by electrochemical detection. The developed analytical protocol overcame the significant practical challenges of atmospheric hydrazine oxidation and minimised the matrix interference in both separation and detection which result from the excess of ammonium with respect to hydrazine (up to 5.8 × 10⁴ times) in GO reduction experiments. Chromatographic separations were achieved using a high capacity IonPac CS16 cation-exchange column with a 30 mM methanesulfonic acid (MSA) eluent, within an analysis time of less than 20 min. Detection of hydrazine as hydrazinium ion using electrochemical detector was linear between 10 μM and 4 mM, with LOD and LOQ values of 3 μM and 10 μM, respectively. Standard additions confirmed 103 ± 0.8% recovery. The developed method was successfully used to determine the point of complete GO reduction with hydrazine. Reaction curves for GO reduction generated using the method were compared to results from Fourier-transform infrared spectroscopy and Raman spectroscopy to verify the utility of the approach.

已经开发了一种新的离子色谱方法，通过监测GO悬浮液中的肼浓度来研究氧化石墨烯（GO）的还原。该方法基于肼（从过量氨中）的离子色谱分离及其通过电化学检测的选择性测定。所开发的分析规程克服了大气中肼氧化的重大实际挑战，并最大程度地减少了因肼比铵过量（最多5.8×10 ^4）而导致的基质分离和检测中的基质干扰。次还原实验中）。使用高容量的IonPac CS16阳离子交换柱和30 mM甲磺酸（MSA）洗脱液，可在不到20分钟的分析时间内完成色谱分离。使用电化学检测器检测肼作为肼离子是线性的，介于10μM和4 mM之间，LOD和LOQ值分别为3μM和10μM。标准添加量确认回收率为103±0.8％。所开发的方法已成功用于确定肼完全还原GO的点。将使用该方法生成的GO还原反应曲线与傅里叶变换红外光谱和拉曼光谱的结果进行比较，以验证该方法的实用性。