Introduction of organic solvent solutions into inductively coupled plasma-atomic emission spectrometry using a microwave assisted sample introduction system

Abstract

A microwave assisted sample introduction system based on the use of a TM 010 cavity (MWDS2) has been employed for the introduction of 10% w/w organic solvent solutions in inductively coupled plasma atomic emission spectrometry (ICP-AES). Ethanol, propan-2-ol, formic and acetic acids have been used. Firstly, the effect of the incident microwave power and the sample uptake rate on the emission signal was evaluated. For all matrices tested, the higher emission signals were obtained when operating at the highest microwave power (i.e., 290 W) and sample uptake rate (400 mL min À1 ). Results with the MWDS2 were compared with those afforded by a desolvation system based on the use of a domestic microwave oven (MWDS) and by a conventional sample introduction system (CS). The MWDS2 provides the highest emission signals (up to 7 and 17 times higher than those with the MWDS and the CS, respectively). As regards the matrix effects originated by the organic solutions, results demonstrate that the use of a microwave-based sample introduction system, mainly the MWDS2, affords a noticeable reduction in the matrix effects originated by the use of organic solvent solutions in ICP-AES with a conventional sample introduction system. This behaviour can be explained by taking into account the solution transport rates afforded by the different sample introduction systems. For all the analytical lines and matrices tested and operating at 400 mL min À1 , the MWDS2 gives rise to signal values that are, on average, 1.2 AE 0.2 times the signal obtained with water. For the MWDS and the CS, this factor takes values of 1.6 AE 0.2 and 2.0 AE 0.5, respectively. Transient matrix effects have been observed operating with the MWDS2 when switching between water and an organic matrix solution. These transient effects result in a drift time about 4.5 times higher than those with a CS.

Application of a microwave-based desolvation system for multi-elemental analysis of wine by inductively coupled plasma based techniques

“…Recently, a new design of a microwave-based desolvation 91 system (MWDS) has been reported in the literature [32,33].…”

“…Nevertheless, the MWDS has 109 been employed successfully to mitigate non-spectral matrix 110 effects in ICP-AES due to the presence of alcohol solutions 111 or organic acids [33]. Thus, the emission intensity obtained acquired at local supermarkets.…”

High-efficiency sample preparation with dimethylformamide for multi-element determination in pharmaceutical materials by ICP-AES

“…Various approaches have been reported in order to avoid, or at least to reduce, these problems. Examples of these include the use of lowflow sample introduction systems [14,15], addition of oxygen to the nebulizer and outer gas flows [14,15], cooled spray chambers [16], and use of desolvation systems [17][18][19]. However, no publication can be found regarding a technique for direct analysis of DMF solutions by ICP-AES.…”

Design and evaluation of a new fully microwave-assisted liquid sample introduction device for inductively coupled plasma atomic emission spectrometry

“…During the last five years a microwave-based thermal nebulizer (MWTN) and a microwave-based desolvation system (MWDS) 20,24 have been separately developed and extensively evaluated by our research group in ICP-AES and ICP-MS. The MWTN consists of a PTFE capillary placed inside of a TM 010 MW cavity.…”

“…Details of both devices are found elsewhere. 10,20,24 MWTN was coupled to a home-made thermostated cyclonic spray chamber (inner volume 33 cm 3 ). The temperature was kept constant at À5 C using a thermostated bath (Haake F3-K, Haake Mess-Technik GmBH U Co, Karlsruhe, Germany).…”