Analytical and Testing Center, Sichuan University, Chengdu, Sichuan 610064, China.
Key Lab of Green Chemistry and Technology of MOE, and College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China.
Anal Chem. 2023 Mar 21;95(11):5151-5158. doi: 10.1021/acs.analchem.3c00306. Epub 2023 Mar 6.
A new compact tandem excitation source was designed and constructed by using an array point discharge (ArrPD) microplasma for a miniaturized optical emission spectrometer through coupling a hydride generation (HG) unit as a sample introduction device. Three pairs of point discharges were arranged in sequence in a narrow discharge chamber to construct the ArrPD microplasma, for improved excitation capability owing to the serial excitation. Besides, the discharge plasma region was greatly enlarged, therefore, more gaseous analytes could be intercepted to enter into the microplasma for sufficient excitation, for improved excitation efficiency and OES signal. To better understand the effectiveness of the proposed ArrPD source, a new instrument for simultaneous detection of atomic emission and absorption spectral responses was also proposed, designed, and constructed to reveal the excitation and enhancement process in the discharge chamber. Under the optimized conditions, the limits of detection (LODs) of As, Ge, Hg, Pb, Sb, Se, and Sn were 0.7, 0.4, 0.05, 0.7, 0.3, 2, and 0.08 μg L, respectively, and the relative standard deviations (RSDs) were all less than 4%. Compared with a commonly used single point discharge microplasma source, the analytical sensitivities of these seven elements were improved by 3-6-fold. Certified Reference Materials (CRMs) were successfully analyzed with this miniaturized spectrometer, which features low power, compactness, portability, and high detectability, and is thereby a great prospect in the field of elemental analytical chemistry.
设计并构建了一种新的紧凑型串联激发源，该源采用阵列点放电（ArrPD）微等离子体，通过将氢化物发生（HG）单元作为进样装置进行耦合，实现了微型光学发射光谱仪的小型化。在狭窄的放电室内顺序排列三对放电点，构建了 ArrPD 微等离子体，由于串联激发，提高了激发能力。此外，放电等离子体区域大大扩大，因此，可以拦截更多的气态分析物进入微等离子体以进行充分激发，提高了激发效率和 OES 信号。为了更好地了解所提出的 ArrPD 源的有效性，还提出、设计和构建了一种用于同时检测原子发射和吸收光谱响应的新仪器，以揭示放电室内的激发和增强过程。在优化条件下，As、Ge、Hg、Pb、Sb、Se 和 Sn 的检出限（LOD）分别为 0.7、0.4、0.05、0.7、0.3、2 和 0.08 μg·L，相对标准偏差（RSD）均小于 4%。与常用的单点放电微等离子体源相比，这七种元素的分析灵敏度提高了 3-6 倍。使用这种微型光谱仪成功分析了认证参考材料（CRM），其具有低功耗、紧凑、便携和高检测能力的特点，因此在元素分析化学领域具有广阔的前景。
