MISP – just add sample
- Metrohm Inline Sample Preparation (MISP) puts an end to manual sample preparation for ion chromatography.
- MISP stands for methods developed by Metrohm that allow you to fully automate the preparation of even the most challenging samples.
- Not only will you increase sample throughput but also improve accuracy and reproducibility of analyses and results.
- The analytical challenge treated in the present work consists in the determination of chloride, phosphate and sulfate in the presence of difficult sample matrices that interact with the stationary column phase or even render it unusable. Metrohm`s patented stopped-flow dialysis coupled to the new 881 Compact IC pro ion chromatograph overcomes these drawbacks.
- Two standard solutions covering the concentration ranges 1.0…3.6 mg/L and 10…36 mg/L as well as two samples, an ultra-high temperature (UHT) processed milk and a baby milk powder, were characterized in terms of analyte concentration, relative standard deviation, calibration quality, carryover and recovery rates.
- While the five-point calibration curves yielded correlation coefficients (R) better than 0.9999, carryover (between two subsequent injections of a concentrated sample and a blank) was less than 0.49%. Recoveries for the low (10…36 mg/L) and high standard concentrations (1.0…3.6 mg/L) were within 91…99% and 94…100%, respectively.
- Automated compact stopped-flow dialysis is a leading-edge sample preparation technique that ensures optimum separation performance by effectively protecting the column from detrimental matrix compounds.
Sample preparation for Metrohm ion chromatography
- In the past 25 years ion chromatography has experienced a turbulent development.
- Innovations in separating columns, suppressors and in instruments and application techniques have played a considerable part in this. In addition, the most important routine methods have been standardized; in this context we may mention the ISO 10304 series and ISO 15061 (anions), ISO 14911 (cations) and DIN 38413-8 (complexing agents).
- Ion chromatography has, similar to classical (RP-)HPLC, reached a high stage of development; the only deficits still to be found are in the sample preparation techniques.
- These deficits have a negative effect on applications, which is particularly noticeable when attempts are made to automate the analytical procedures.
- The aim of this Monograph is to provide an overview of the sample preparation techniques for ion chromatography (Frenzel) and to present solid-phase extraction (SPE), the most widespread sample preparation technique, with all its advantages and disadvantages (Seubert).