2007

ANALYTICAL TOPICAL GROUP

Annual Report

Officers 2007

Chairman   Robert P. Nolan, PhD
International Environmental Research Foundation
Post Office Box 3459
Grand Central Station
New York, NY 10063-3459
Tel/Fax (800) 709-0028
E-mail  rnolan@ierfinc.org
 

Chairman Emeritus  William E.L. Grossman
Department of Chemistry
Hunter College of The City University of New York
695 Park Avenue
New York, NY   10021
Tel (212) 772-5338/5330
Fax (212) 772-5332

Board
David C. Locke, Director
Department of Chemistry
Queens College of The City University of New York
65-30 Kissena Boulevard
Flushing, NY   11367-1597
Tel (718) 997-3271

Thomas Kubic, Director and Program Chair
John Jay School of Criminal Justice , CUNY
899 Tenth Avenue
New York, NY 10019

Urs Jans, Director
Department of Chemistry
The City College of The City University of New York
Convent Avenue & 138th Street
New York, NY   10031
Tel (212) 650-8369/6052
Fax (212) 650-6107
E-mail: ujans@ccny.cuny.edu
 

The Analytical Topical Group hosted six seminars this year. We continue with the participation of the forensic faculty and students from John Jay School of Criminal Justice. We had one seminar by a forensic scientist - Dr. Jo Ann Buscaglia from the FBI Laboratory. Last fall we started inviting speakers from the local colleges’ particularly junior analytical faculty to give a talk in the topical group series. We will be continuing this into the spring of 2008 as we still have speakers on our list.  Attendance continues to be about 20 per seminar.
 

Treasurer’s Report: $650.00
Minutes of Meetings: No formal meetings were held.

Wednesday - February 28, 2007, at 6 PM

“Industrial Applications of Microscopy to Study Paint and Waterborne Coatings”

Dr. John R. Reffner

The Rohm and Hass Company

Microscopy is often an important tool in studying paint and waterborne coatings.  In this seminar I will present some typical examples of the use of transmission electron microscopy, scanning electron microscopy and optical profilometry to study the visual appearance of films, defects in films and performance issues.

 Dr. John R. Reffner is currently the Team Leader for the Microscopy Group in the Central Analytical Support Department at Rohm and Haas Company where he has been employed since 1991.  He received his Ph. D. from the University of Massachusetts in Polymer Science and a B.S. in Chemistry from Rensselaer Polytechnic Institute.

 The Graduate Center of the City University of New York
365 Fifth Avenue
New York, NY
 
 
 
 
 
 

Wednesday - March 21, 2007, at 6 PM

“Solving Unusual Chemical Problems Using the Infrared Microprobe”

Dr. John A. Reffner

Senior Scientist and Research Director Smiths Detection, and Adjunct Professor at
John Jay College of Criminal Justice and the Graduate Center, CUNY as well as a Consultant in Analytical Microscopy


The growing trend in analytical chemistry to a culture of "dilute-and-shoot" fails to address many challenging problems in forensic, geological, material and pharmaceutical sciences.  When different batches of an active pharmaceutical ingredient are found to have different solubility, melting points or processing properties, it is essential to directly analyze the solid and determine both its physical and chemical properties.     Molecular spectroscopy, optical microscopy and x-ray diffraction are methods for detecting and identifying polymorphic forms.  Telling a mineralogist that a rock contains calcium carbonate is only half the answer; is it calcite or aragonite? Multiplayer laminates are commonly used as packaging materials.  A bulk chemical analysis of these films has little value.  Each layer must be identified and sequenced in the film's structure.  The forensic scientist is challenged to identify and link evidence to a common source or incident, while maintaining the evidence and records for legal review.  The infrared microprobe is a valuable tool for nondestructive analysis of molecular chemistry and microstructure, providing solutions to many unusual problems.   Dr. John A. Reffner, received his Ph.D. from the University of Connecticut (Storrs, CT).

 The Graduate Center of the City University of New York
New York, NY
 
 
 
 
 

Thursday - April 5, 2007, at 6 PM

INCREASING TREND IN DUST CLOUD INTRUSIONS FROM THE ARABO-SAHARAN REGION OVER ISRAEL

ELIEZER GANOR
Department of Geophysics and Planetary Sciences
Tel-Aviv University
POB 39040, Tel-Aviv 69978
ganor@post.tau.ac.il


 


Israel experiences periodic intrusions of natural mineral dust clouds from Africa. The natural contribution of aerosols from Dust Events (DE) can increase PM10 to 4000 _g/m3 half-hour average, a hundred times the concentration on clean days. Observations and measurements of mineral dust were recorded over the 49 year period 1958/9-2005/2006 in Tel-Aviv and Jerusalem. Dust was identified by visibility of less than 5000 meter and the presence of yellow-orange desert dust in rain-water. These comprise 18000 days of observation. From 1995 to 2006 concentrations of aerosols with diameter less than 10 micron (PM10) were measured by TEOM in Tel-Aviv, by the Israel Electric Company and the Ministry for Protection of the Environment. The records were analyzed for statistics such as beginning, duration and concentration. This data may help explain the meteorological and physical processes involved in the Dust phenomena.

Results:

1) The number of days with DE in Tel-Aviv per year has increased 1958-2006 with a slope of 2.3 days per decade, from 18 days in 1962 to 27 days in 2006.

Automatic continuous measurements are available only since 1995. For this period our results are:

2) Duration of DE was 3 to 72 hours, most fell in the range of 3-8 hours.

3) Most DE were observed to begin in Tel-Aviv between 5:00 and 8:00 in the morning, with the breaking of the inversion, and ended between 8:00 and 15:00 hours.

4) 13%-40% of DE in each year ended in rain.

5) The total duration of DE in Tel-Aviv over a year was 172 to 495 hours, average 328 hours/year.

6) The contribution of DE caused PM10 values to exceed the Israeli standard of 60 _gr/m3/year in 6 of the 12 years. Using our DE identification algorithm we computed the average PM10 with and without DE. However, even without the DE contribution PM10 exceeded the level recommended by WHO (20 _gr/m3/year) every year. PM2.5 values were over the Israeli recommended standard (15 _gr/m3/year) even without DE.

7) The contribution of DE to the annual PM10 average was 9%-27%.

These results may indicate the effect of global or local change, such as desertification, on dust intrusions. The dust could in turn affect weather and climate through direct (redistribution of heat in the atmosphere) and indirect (cloud and precipitation) effects. DE statistics are relevant for transportation e.g. through visibility, and for public health concerns.

The Graduate Center of the City University of New York
365 Fifth Avenue
New York, NY
 
 
 
 

Monday - May 14, 2007, at 6 PM

The Use of Elemental Profiles for the Comparison of Physical Evidence

Dr. JO ANN BUSCAGLlA
Counterterrorism and Forensic Science Research Unit
Federal Bureau of Investigation Laboratory
Quantico, VA.


Elemental composition has been used as a point of comparison for evidentiary items such as glass, polymers, and metal alloys in forensic investigations for over 30 years with many notable successes.  Improvements in analytical methods and their more widespread availability to a large number of forensic laboratories have renewed interest in this forensic application of analytical chemistry.

Comparison of recovered glass fragments with a broken window is, perhaps, the best example of the power inherent in the determination of elemental composition.  Several analytical methods are available to determine the concentrations of from 10 to 50 elements in glass fragments with a high degree of accuracy and precision.  Other materials of forensic interest can be more challenging than glass, both for the development of analytical protocols and the interpretation of results.  Considerations for the use of element compositions for source discrimination for a variety of materials, including analytical, sampling, and manufacturer effects, will be presented.  Methods for addressing these considerations will be illustrated using the analytical results from copper wire, glass, plastic trash bags, solder, soil, and other materials.

Dr. Buscaglia received her Ph.D. in Criminal Justice/Forensic Science from C.U.N.Y in 1999 and her B.S. (1986) and M.S. (1988) in Forensic Science from John Jay College of Criminal Justice.  Her dissertation involved the forensic characterization of trace elements in polyethylene trash bags by total-reflection x-ray fluorescence (TXRF) spectrometry.  Dr. Buscaglia has been employed by the FBI Laboratory since 1998 and is currently a Research Chemist in the Counterterrorism & Forensic Science Research Unit.  Dr. Buscaglia performs forensic science research primarily in the areas of microscopy, elemental analysis of trace evidence, and statistical interpretation of forensic data.

The Graduate Center of the City University of New York
365 Fifth Avenue
New York, NY

Science Center Room 4102
 
 
 
 
 

Wednesday - October 10, 2007, at 6 PM

Vibrational Microscopy and Imaging: Applications to Skin Pharmacology, Biochemistry and Biophysics

RICH  MENDELSOHN,
Professor of Chemistry,
Rutgers University, Newark, NJ, 07102


Vibrational microscopy and imaging are now poised to address important biomedical issues, including the diagnosis of pathological states.  A major advantage of these technologies, not widely utilized to date in imaging applications is the availability of direct molecular structure information inherent in IR and Raman spectroscopies.

Skin provides a unique opportunity for extending vibrational spectroscopic imaging to diverse areas including drug delivery, drug metabolism, and single cell biochemistry. Recent studies from our laboratory that auger well for vibrational microscopy applications to a variety of tissues will be discussed as time permits, and include the following:

1) Pro-drugs are used to enhance the delivery of therapeutic agents into skin, where they are hydrolyzed by enzymes and converted to the chemically active form of the drug. We have demonstrated the feasibility of tracking and spatially imaging, via confocal Raman microscopy, the prodrug-to-drug inter-conversion for a derivative of 5-fluorouracil, a well-known anti-cancer agent.

2) Using IR microscopy of single corneocytes isolated from particular depths within the stratum corneum, we have monitored the depth dependence of the relative concentration of the major skin humectant (natural moisturizing factor). This substance controls many skin enzymatic events, as well as the shedding processes that occur in the outer layers.

3) Proper wound healing entails a complex spatial and temporal series of events. Preliminary vibrational microscopy measurements provide evidence for the spatial evolution collagen orientation and hydration that appear during the sequence of the healing process. Our goal is to correlate phenotypes with the sequence of genes that regulate the healing events.

The Graduate Center of the City University of New York
 365 Fifth Avenue
New York, NY

Science Center Room 4102
 
 
 
 

Wednesday - October 24, 2007, at 6 PM

Iridium Oxide (IrOx) Based Fuel Acidity Sensor

JUSTYNA WIDERA
Adelphi University,
Department of Chemistry,
 1 South Avenue, Garden City, NY 11530
E-mail: widera@adelphi.edu


The measurement of acidity in organic liquids is a difficult, but important technique, for instance to ascertain the acidity of petroleum products. Measuring acidity of petroleum products during refining, storage and application is useful as a diagnostic tool for specification tests, thermal stability monitoring, R & D tool for additive development and process control application. Traditional electrochemical pH measurement technology is poorly suited for the nonaqueous environments. The measurement of acidity in organic solvent base matrices like petroleum products is much more difficult due to their complexity and the fact that they are extremely non-conducting. Currently the measurement of “Total Acid Number” in non-conducting fluids is performed by tedious, time consuming and solvent intensive methods based on titration.

This presentation will describe our efforts to develop an iridium oxide (IrOx) based acidity sensor suitable for work in low conducting media like jet fuel. The sensing probe is potentiometric and consists of the indicating and the reference electrodes. A novel iridium oxide electrode is utilized as the indicating electrode and a Ag/AgCl or Ag/Ag2O - reference electrode. When the sensing probe is exposed to the solution containing the analyte of interest, the signal is observed as a change in potential relative to the reference electrode. We have conducted extensive studies using this detector system and obtained data showing its range of detection of pH/acidity in aqueous and non-aqueous solutions. The IrOx sensor responds to compounds present in fuel that have acid-base character. This sensor allows the determination of the acidity of different fuels and to discriminate between neat and thermally stressed fuels. The correlation of the response of an IrOx sensor with the total acid numbers of different fuels will be presented. Experimental results also indicate that the low conductance of fuel and / or the material used for sensor encapsulation may influence the response time of the IrOx sensor.

We will show the feasibility of the IrOx sensor with respect to the potential application as a fast, accurate real-time acidity sensor for the testing of petroleum products. Finally, by the comparable studies of other commercially available pH sensors, the IrOx response will be demonstrated to be faster, better defined, more accurate and more
reproducible than a response of the other commercially available sensors in non-aqueous solutions.

The Graduate Center of the City University of New York
365 Fifth Avenue
New York, NY

Science Center Room C203