Research Synopsis: Applied analytical chemistry, multi element trace analysis of environmental and geological samples, forensic omega-3 dietary supplements, counterfeit consumer products
Phone: (848) 445-2590
Members of Professor Gene Halls research team will be trained with the latest state-of-the-art instrumentation in analytical chemistry. These instruments include a Fisons Instruments PlasmaQuad 2+ ICPMS, a Finnigan Element High Resolution ICPMS, and a gradient HPLC system. Your multidiscipline education will include forensic, biological, statistical, environmental, and analytical chemistry. After receiving your training and degree under my supervision, you will have excellent marketable skills to obtain employment in the exciting field of analytical chemistry. The focus of Professor Halls research team is composed of five major themes.
Identification and quantification of Pb, Cu, and Zn binding proteins in human tissues
Theme one is bio-analytical chemistry and focuses on the identification and quantification of Pb, Cu, and Zn binding proteins in human biological tissues. In collaboration with the University of Medicine and Dentistry of New Jersey (UMDNJ) - Robert Wood Johnson University Hospital, we obtain samples of human blood, follicular fluid, placenta, and amniotic fluid. We use high performance liquid chromatography (HPLC) as the method to identify and separate metal binding proteins in these fluids. The output flow solution from the HPLC is fed to an inductively coupled plasma mass spectrometer (ICPMS) to quantify elements bound to the proteins. This research allows for the first time a unique analytical method (HPLC-ICPMS) to investigate the effects of Pb speciation on metal binding proteins and Pb toxicity.
The HPLC-ICPMS is used to study pre-natal Pb poisoning and with emphasis of the importance of avoiding Pb before, during, and after pregnancy.
Environmental analytical chemistry: identification of sources of Pb in drinking water
Our second theme of research is environmental analytical chemistry that focuses on identification of sources of Pb in drinking water, consumer products (watches, dinner plates, children's toys) and food and drink. Because Pb has four stable isotopes, we determine the differences in the amount of these isotopes in drinking water. This unique water-lead isotope "fingerprint" is compared to lead isotope "fingerprints" from plumbing materials that include solder, faucets, valves, and Cu pipe. The "fingerprints" are determined by high resolution ICPMS and statistical methods are used to determine the source(s) of Pb contamination.
We also use non-destructive macro and micro energy dispersive X-ray fluorescence (EDXRF) to determine the amount of Pb, Sb, As, and Ba in various consumer products. For example, Figure 1 below shows Pb imaging in a carton character watch marketed for children ages three and above which is in violation of consumer protection laws.
Our third theme is forensic dietary supplements that are marketed as containing omega-3 fatty acids. According to recent statistics, fish oil is the sixth most consumed dietary supplements in the US. Unfortunately, a majority of these misbranded and/or adulterd dietary supplements do not contain "fish oil". Instead, they contain marine biodisel that are the ethyl esters of fatty acids. We are using cold electron impact gas chromatography time of flight mass spectrometry (GC-TOF-MS) to perform impurity profiles of these misbranded dietary supplements. Our research has shown that the analyses of more than 3,000 dietary supplements contain omega-3 fatty acids EPA, DHA, EPA, and ALA in the less bioavailable form ethyl esters. Figure 2 shows the total ion chromatogram of a fish oil dietary supplement marketed as "100% natural". The chromatogram shows more than 60 different impurities that are not disclosed on the supplement facts panel as required by law.
Our fourth theme involves non-destructive charactization of counterfeit consumer products such as Rolex watches, Coach handbags, Barbie dolls, and jewelry. We have an extensive collection of Coach handbags that were analyzed for trace elements using EDXRF. Using this non-destructive analytical method, we can easily differentiate between the counterfeit and the geniune. Consumers who purchased these counterfeity products should be aware of high concentrations of Pb in some of the hangtags.
Our fifth theme involves non-destructive characterization of postal stamps and banknotes. This is in collaboration with collectors as a means to characterize these precious cultural heritage objects. Figure 3 shows a collection of old NJ banknotes that we used FTIR, Raman, and EDXRF to understand the trace element composition of the inks and papers.
S. Xue, G.F. Herzog, G.S. Hall, B. Dong, and D.E. Brownlee, Nickel isotope abundances of Type I Deep-Sea Spheres and of Iron-Nickel Spherules from Alberta (Canada) Sediments. Geochimica et Cosmochimica Acta, Vol. 59, 4975-4981, 1995.
S. Yu, G. S. Hall, D. Persuad, S. Marcus and T. Jennis, Chronology of Pb Isotope Ratios and Concentrations in Biological Fluids From a Gun-Shot Victim. ICP Information Newsletter, Vol 22, 61, 1996.