Development of an electrothermal vaporization ICP-MS method and assessment of its applicability to studies of the homogeneity of reference materials

• Published in: Analytical and bioanalytical chemistry Vol. 370; no. 5; pp. 499 - 507
• Main Authors: FRIESE, K.-C, GROBECKER, K.-H, WÄTJEN, U
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Berlin Springer 01.07.2001; Springer Nature B.V
• Subjects: Analytical chemistry; Arsenic - analysis; Cadmium - analysis; Chemistry; Copper; Copper - analysis; Evaporation; Exact sciences and technology; Homogeneity; Inductively coupled plasma mass spectrometry; Iron - analysis; Lead - analysis; Manganese; Manganese - analysis; Mass Spectrometry; Organic compounds; Pyrolysis; Reference materials; Reproducibility of Results; Spectrometric and optical methods; Spectrometry; Standard deviation; Temporal resolution; Trace Elements - analysis; Vaporization; Volatilization; Zinc - analysis; Trace analysis; Arsenic; Coupled method; Diffuse reflection; Instrumentation; Standard; Transition metal; Nebulization; Inductive coupling plasma spectrometry; Certified reference material; Infrared spectrometry; Repeatability; Sensitivity; Simultaneous measurement; Homogeneity; Lead; Thermoelectric atomization; Standard deviation; Mass spectrometry
• ISSN: 0937-0633; 1618-2642; 1432-1130; 1618-2650
• DOI: 10.1007/s002160100868

A method has been developed for measurement of the homogeneity of analyte distribution in powdered materials by use of electrothermal vaporization with inductively coupled plasma mass spectrometric (ETV-ICP-MS) detection. The method enabled the simultaneous determination of As, Cd, Cu, Fe, Mn, Pb, and Zn in milligram amounts of samples of biological origin. The optimized conditions comprised a high plasma power of 1,500 W, reduced aerosol transport flow, and heating ramps below 300 degrees C s(-1). A temperature ramp to 550 degrees C ensured effective pyrolysis of approximately 70% of the organic compounds without losses of analyte. An additional hold stage at 700 degrees C led to separation of most of the analyte signals from the evaporation of carbonaceous matrix compounds. The effect of time resolution of signal acquisition on the precision of the ETV measurements was investigated. An increase in the number of masses monitored up to 20 is possible with not more than 1% additional relative standard deviation of results caused by limited temporal resolution of the transient signals. Recording of signals from the nebulization of aqueous standards in each sample run enabled correction for drift of the sensitivity of the ETV-ICP-MS instrument. The applicability of the developed method to homogeneity studies was assessed by use of four certified reference materials. According to the best repeatability observed in these sample runs, the maximum contribution of the method to the standard deviation is approximately 5% to 6% for all the elements investigated.