High Throughput, Multi-Element Analysis of Effluents by Microwave Plasma-AES (MP-AES)

Effluents are produced by a wide range of industrial, commercial, and agricultural processes. To prevent potentially harmful elements such as As, Cd, Pb, and Hg from contaminating the environment, effluents must be analyzed before they are discharged or treated. The presence of trace amounts of Cd and Pb in surface or ground waters can affect soil fertility and plant growth, as well as accumulating in fish. Many regulations specify maximum permitted concentrations of several elements that must be evaluated in effluents before disposal. In this study, the list of elements tested includes Ag, As, B, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sn, and Zn.

Various atomic spectrometric techniques have been used to analyze wastewaters, including Flame Atomic Absorption Spectrometry (FAAS), Graphite Furnace-AAS (GFAAS), Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES), and ICP-Mass Spectrometry (ICP-MS). However, as contract and quality control (QC) laboratories look to improve their efficiency while providing high-quality data, many have added Microwave Plasma-AES (MP-AES) to their range of elemental analysis techniques. MP-AES runs unattended without the need for flammable or expensive gases, or hollow cathode lamps, improving laboratory safety and reducing operating costs.

The Agilent 4210 MP-AES uses microwave energy to generate a robust and stable plasma using nitrogen (N2) gas. The N2 can be extracted straight from air using the Agilent 4107 Nitrogen Generator or be supplied from a tank or Dewar. Compared to Flame AAS there are considerable savings in operating costs which can be calculated with the online calculator. For the analysis of effluents under the CONOMA 430 method, the savings in operating costs means the MP-AES pays for itself in as little as 5 months*. MP-AES is a multi-element technique that is more suited to high throughput applications than FAAS.

All measurements were performed using an Agilent 4210 MP-AES equipped with an SPS 4 autosampler and AVS 4 switching valve. The instrument was fitted with a OneNeb Series 2 nebulizer, double-pass glass cyclonic spray chamber, and Easy-fit torch. For the analysis of As, Se, and Hg, the 4210 was fitted with the optional multimode sample introduction system (MSIS) accessory. By separating volatile hydride species from the sample or using cold vapor generation, the MSIS provides better performance and lower detection limits than conventional nebulization.

To learn more, view the full application note HERE