Abstract Standard reference material (SRM) 2584 (Trace Elements in Indoor Dust) was developed as a reference standard for evaluating field methods and for validating laboratory and reference methods for the assessment of lead contamination and exposure. In addition to lead, the toxic trace elements As, Cd, Cr, and Hg, at approximately 17, 10, 140, and 5 μg g –1 , respectively, have been certified in the SRM. These four analytes were successfully deter- mined by use of high-resolution inductively coupled plasma mass spectrometry (HR-ICP–MS). Isobaric interferences at masses of As and Cr were resolved by using the high resolution mode (nominal 8000) and the medium resolu- tion mode (nominal 3000), respectively, of the instrument. The effects of a significant drift in analyte sensitivity in the course of measurement were rectified by use of in- ternal standardization, single spike standard addition, and an optimized analysis sequence. The results were com- pared with those obtained by instrumental neutron activa- tion analysis (INAA) and isotope dilution inductively coupled plasma mass spectrometry (ID-ICP–MS). The re- sults for the quality control, SRM 2704 (Buffalo River Sediment), were in good agreement with the certified val- ues, indicated by the uncertainty intervals of the measured values overlapping the certified intervals at 95% confi- dence level. Introduction Lead poisoning is a major environmental health hazard for children. A child exposed to high levels of lead can suffer from a variety of health effects, including hyperac- tivity, lethargy, hearing or memory loss, or learning dis- abilities [1]. A primary source of the lead contamination in the indoor environment is the lead-based paint that was widely used in residential areas before the 1970s. As a re- sult, the United States Environmental Protection Agency (EPA) included prevention of lead-based paint poisoning as part of the Toxic Substances Control Act, which is codified in the Federal Regulations [2]. Standard Reference Material ® (SRM) 2584 (Trace Elements in Indoor Dust) was developed at the request of EPA. The SRM contains a nominal mass fraction of 1% lead, and is designed to be a reference material for indoor dust contaminated by lead- based paint. It serves as a tool in assisting field method development, in evaluating sampling methods, and in validating laboratory methods for the assessment of lead contamination and exposure [3, 4]. As part of the certification program the mass fractions of the toxic metals As, Cr, Cd, and Hg in SRM 2584 were determined by plasma source mass spectrometry [5]. Be- cause complete digestion of the dust sample requires per- chloric acid, determination of As and Cr by quadrupole ICP–MS is susceptible to interferences by 40 Ar 35 Cl + , 35 Cl 16 O 1 H + , and 37 Cl 16 O + at 75 As + , 52 Cr + , and 53 Cr + , respec- tively. As an alternative to quadrupole ICP–MS, which cannot resolve isobaric interferences at the masses of As and Cr, As is routinely measured by atomic absorption spectrometry (AAS) [6], and Cr is measured by induc- tively coupled plasma optical-emission spectrometry (ICP–OES) [7] or X-ray fluorescence (XRF) [8]. High-resolution inductively coupled plasma mass spec- trometry (HR-ICP–MS) is capable of resolving many plasma-, water-, and matrix-based polyatomic interfer- ences, and the technique has been used for the successful determination of elements subject to spectral interference in samples with complex matrices [9]. The argide, chlo- rine hydroxide, and chlorine oxide ion interferences with 75 As, 52 Cr, and 53 Cr can be resolved at resolutions greater than 7800, 1700, and 2600, respectively. The trade-off for using a higher resolution mode in the determinations of As and Cr is reduced analyte sensitivity. Here we report Lee L. Yu · Robert D. Vocke · Karen E. Murphy · Charles M. Beck II Determination of As, Cd, Cr, and Hg in SRM 2584 (Trace Elements in Indoor Dust) by high-resolution inductively coupled plasma mass spectrometry Fresenius J Anal Chem (2001) 370 : 834–837 © Springer-Verlag 2001 Received: 13 December 2000 / Revised: 30 March 2001 / Accepted: 7 April 2001 ORIGINAL PAPER Presented at the Eighth International Symposium on Biological and Environment Reference Materials (BERM 8), Bethesda, MD, USA, September 2000 L. L. Yu () · R. D. Vocke · K. E. Murphy · C. M. Beck II Analytical Chemistry Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899–8391, USA e-mail: lee.yu@nist.gov