Hi! If you dilute your samples, for example, 50 times and your spectrometer is still able to quantitatively measure the elements in question, then the problem is solved. However, if the detection limits achieved by the spectrometer are not sufficient, methods that remove matrix elements must be used.

ZJ

You can do a small digestion and then later take an aliquot and dilute if the sediments are also on high concentration, or as Zbigniew Jońca recommends straight dilute, it is the best way. Remember for matching the matrix to the standard (in case this be prepared with nitric), adding some drops of nitric acid if the water solution is clear. Samples with high salinity are prone to either block directly the nebulizer or deteriorate the skimmer cones.

Zbigniew Jońca if the detection limits achieved by the spectrometer are not sufficient, what method (s) do you recommend to remove matrix elements?

Hi! Please tell us what ICP-MS spectrometer you have, i.e. manufacturer, model? Which trace elements can be measured and in what concentration ranges are they found in your samples? What lower values of the determination interval are required for individual elements? What are the main ionic components contained in this approximately 12 g/L? NaCl? Do you have the results of previous analyzes of your current or previous samples? Can you also have access to the ICP-AES spectrometer (ICP-OES)?

Z.J.

Zbigniew Jońca

We have Agilent 7800 ICP-MS spec. I intend to measure Cd, CO, Cr, Cu, Pb, AS, Mn, Se, Ni, Zn, and Fe. I do not have any idea of the concentration levels that these trace metal(loid)s are found in my samples as there were no data in the literature where these elements were analyzed in the rivers sampled. Apart from the direct salinity test conducted on the samples, no further test was conducted to determine the ionic components. Presently, I do not have access to ICP-MS spec.

Thanks you for your interest in my research

This means that it is a relatively new spectrometer that is certainly suitable for performing the measurements you need.

This spectrometer is probably equipped with a High Matrix Introduction system (HMI), thanks to which it is enough to dilute the samples, e.g. 5 times, or even without it, if there are few samples and there is no need to maintain the stability of the spectrometer's readings for many hours.

If your spectrometer is also equipped with the Integrated Sample Introduction System Discrete Sampling ISIS-DS), then there is certainly no need to dilute your samples at all, which would be the most beneficial for the labour intensity, time consumption and metrological quality of spectrometric measurement results.

As for the preparation of your samples for spectrometric measurements, it depends on what is being analyzed. Only the solution or together with any suspension is present, because the measurement results of many trace elements may then differ significantly. Similarly, the possible presence of organic substances, dissolved or contained in suspension, especially in such quantities that they may affect the physical properties of the sample and even the course of processes in the argon plasma. So, is it enough to just acidify the samples, or acidify them only after filtration? Is the destruction of organic substances necessary? The best solution for this purpose is the so-called mineralization with H2O2, combined with UV irradiation.

As for the spectrometric measurements themselves, the general approach and many detailed recommendations are provided, for example, by USEPA Method 6020B Rev.2 July 2014. Specific conditions and instrumental parameters can be found in various information materials and recommendations of the spectrometer manufacturer, available on its website. There are several applications available for download that describe the analysis of saline water samples, even seawater. It would be best if you started with preparatory and measurement procedures from another laboratory, equipped with a spectrometer like yours or similar, which deals with the analysis of saline water samples daily. It is also crucial to start with obtaining ready-to-use calibration and control solutions from another laboratory, including those with the status of reference materials.

Good luck.

ZJ