Inductively coupled plasma (ICP) mass spectrometry is a form of mass spectrometry that employs inductively coupled plasma to ionize a sample. It atomizes the sample and forms atomic and small polyatomic ions which can then be detected.
ICP standards are used in ICP-OES, which is a trace-level, elemental analysis method that uses the emission spectra of a sample to recognize and quantify the elements present. The involved elements can be recognized by their characteristic emission lines and quantified by the intensity of the same lines. Trace analysis is often thought of as an analyte concentration low enough to cause challenges. The challenges may be caused by the sample size, matrix, or washout issues.
What Can be Done about Washout?
Washout refers to sample solution being removed from the sample introduction system during analysis. Ensuring that the previous sample has been completely removed before introducing the next sample for analysis will eliminate carryover contamination from one sample to the next. This carryover contamination can cause incorrect results by either introducing interferences that should not be present or artificially adding elements of interest.
Some solutions contain elements that need hydrofluoric acid (HF) to maintain stability. Sample introduction systems are used in ICP and are often made of borosilicate glass. Introducing samples containing HF will cause Boron and Silicon to leach out of the glass sample introduction system parts and into the sample solution. ICP analysts will sometimes use an HF resistant system such as PFTE and PFA, however certain elements will still leach out of the coatings used in the plastic sample introduction parts. This carryover from HF resistant sample introduction system parts will increase as the concentration of HF increases.
When trying to remove washout issues when dealing with ICP standards, it's key to ensure that all parts of the sample introduction system are clean. Some elements are more of a challenge to remove through standard cleaning processes and may require that parts are soaked in cleaning solution or even replaced more frequently. One specific part that can be easy to overlook is PVC peristaltic pump tubing.
Performing the correct rinse protocol is a critical part of avoiding washout issues. It can take some experimentation to understand how much time should be spent rinsing the equipment and what rinse solution should be used is of the utmost importance. Dilute acid or water may be good enough to ensure the elimination of carryover contamination for relatively simple sample analysis. However, depending on the instrument method and the analytes/concentrations of interest the ICP analyst may dictate the use of more exotic rinse solutions.
Benefit of Using ICP Standards from Inorganic Ventures
Inorganic Ventures is an optimal company to work with as they create custom solutions, rather than off-the-shelf ones. Custom solutions cater to exactly what each experiment needs, providing higher concentration ranges for user dilution. This means that unnecessary elements are not added to solutions which could result in carryover contamination.
ICP standards from Inorganic Ventures can save users time and enhance stability, ensuring everything in the custom standards are suitable for the methods being used. We can also make recommendations for matrix and elemental compatibility, ensuring the utmost suitability.
Inorganic Standards has a wealth of experience in wet chemistry and advanced fractionation. Our portfolio of certified reference materials (CRMs) is created to be used in ICP, ICP-MS, IC, atomic absorption, wet chemistry, and QC applications. Our products are produced to be stable, compatible, NIST-traceable, and are designed and tested under ISO 17034 & ISO 17025 guidelines.
To find out more, contact our team of experts for more information.