David L. McCurdy

Professor of Chemistry
Department of Chemistry
Truman State University
Kirksville, MO 63501
(660) 785-7250
(660) 785-4045 (fax)
dmccurdy@truman.edu

Education

• B.S., Northwest Missouri State University
• Ph.D., Kansas State University

Courses Taught

• Chemistry for Contemporary Living
• Chemical Principles I
• Chemical Principles II
• Quantitative Analysis
• Instrumental Analysis
• Advanced Analytical Chemistry

Research Interests

Dr. McCurdy's research interests are in the area of analytical chemistry. His current work includes: (1) the Development of Methods for Trace-Level Elemental Analysis using Atomic Spectroscopy (including the Inductively Coupled Plasma, Direct Current Plasma, and Flame and Furnace Atomic Absorption Spectrophotometry), (2) the Development and Applications of Methods of Sample Introduction in Plasma Emission Spectrometry, (3) the Preparation and Treatment of Samples for Analysis, (4) the Development of New Laboratory Experiences for Undergraduate Classes in Analytical Chemistry, and (5) the Advancement of Undergraduate Research.

Modern methods for the analysis of trace (10-3 to 10-6%) and ultra-trace (10-6 to 10-9%) level elements rely heavily on the use of atomic spectroscopy, particularly the use of the inductively coupled plasma (ICP), direct current plasma (DCP), and graphite furnace atomic absorption spectrophotometry (GFAAS). In particular, the ICP and DCP have gained wide acceptance as the "instrument of choice" by analytical chemists because of their speed, sensitivity, selectivity, and simultaneous multielement capabilities.

Despite the power of plasma methods, they are not free from weakness. The introduction of samples into the ICP or DCP is considered to be a weak link in plasma spectroscopy. Most accepted methods for the introduction of samples into plasmas require the sample to be in the form of a dilute, aqueous solution with appreciable solid samples or in samples in which very limited quantities of material are available, this can prove to pose difficulties to the analyst.

Dr. McCurdy's research work is aimed at developing new approaches for the introduction of solid or microliter/microgram-quantity samples into the ICP and DCP. The work includes projects which are designed to reduce the amount of time and effort in preparing samples for rapid ICP and DCP elemental determinations, to develop methods for the direct introduction of solid samples, and to investigate methods of introduction of microsamples.

One approach currently being investigated is the use of electothermal vaporization (ETV) as a method of introducing samples into the DCP. In ETV sample introduction, microliter-sized samples are introduced on a carbon rod which is electrically heated, vaporizing the samples form the surface of the rod and ultimately into the DCP for atomic emission measurement. ETV-DCP will allow the introduction of solid or liquid samples, uses small quantities, and several projects centering around the use of community. They include studies evaluating the performance of ETV-DCP for ultra-trace level analysis in microsamples, the subsequent efforts to further improve its performance and the development of methods for the determination of ultra-trace level elements in complex samples.

Other projects being pursued in Dr. McCurdy's lab include methods of sample preparation for analytical chemistry using microwaves and the development of other forms of sample introduction for plasma spectroscopy, including slurry nebulization and thermospray nebuilzaiton.

Current Research Projects

The Development of Electrothemal Vaporization for Sample Introduction into the Direct Current Plasma

This project involves the design, development and characterization of ETV for the introduction of samples into the DCP. Students currently are critically evaluating the performance characteristics of a carbon rod vaporizer, and using these results to redesign the ETV-DCP system to further improve the reproducibility and efficiency of analyte transport of the system.

The Use of ETV-DCP for the Direct Determination of Trace-Level Elements in Coal

Students are taking advantage of the capability of ETV to allow the direct introduction of solid materials in the plasma and are working to develop quantitative methods for the direct determination of trace-level elements in solid coal samples, introduced in the form of slurries. The objective is to develop a method which involves little or no sample pretreatment prior to the measurement, as compared to current methods which involve time-consuming wet or dry ashing decomposition.

The Determination of Trace-Level Boron in Sodium Metal Using ETV-DCP

Boron impurities in sodium metal occur in the low part-per-million level and in smaller concentrations. In response to an industrial concern over these impurities, approaches for the sensitive, quantitative determination of boron and other metals present in samples of sodium metal are being pursued. The objective is to create a method which allows the rapid determination of these metals in the part-per-billion range.

The Integration of Microwave Sample Preparation into the Undergraduate Analytical Chemistry Curriculum

Efforts by students working with Dr. McCurdy are also focusing on approaches designed to bring more focus on sample preparation methods, particularly that of microwave decomposition and dissolution techniques, into quantitative analysis and instrumental analysis classes at the undergraduate level.