University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Classification: Biological material -> hair -> human

Citations 13

"Simultaneous Determination Of Trace Metals In Human Hair By Dynamic Ion-exchange Chromatography"
Anal. Chim. Acta 1993 Volume 274, Issue 1 Pages 163-170
A. Sturaro*, G. Parvoli and L. Doretti, S. Zanchetta and G. Allegri, G. Battiston

Abstract: Sample was washed with non-ionic detergent solution, followed by Soxhlet extraction with ethyl ether. After drying at 105°C for 12 h, the sample was pulverized and digested with HNO3 - HClO4. The digest was evaporated to dryness and the residue was dissolved in mobile phase and mixed with Co solution (200 mg l-1; internal standard). Analysis was on a column (15 cm x 3.9 mm) of Waters Delta Pak RP-18 (5 µm) with aqueous 5% acetontrile containing 0.0433% sodium octanesulfonate and 0.6063% sodium hydrogen tartrate (adjusted to pH 3.65) as mobile phase (0.75 mL min-1) and UV and photodiode array detection at 546 and 492 nm, respectively. Online post-column derivatization with monosodium 4-(2-pyridylazo)resorcinol resulted in improved absorbance in the UV region. The simultaneous determination of Cu, Zn, Ni, Mn, Pb and Co was achieved with detection limits of ~1 µg g-1. Calibration graphs were rectilinear in the ranges 50 to 600 µg g-1, 2 to 80 µg g-1, 1 to 25 µg g-1, 5 to 200 µg g-1 and 0.1 to 2 µg g-1 for Zn, Cu, Ni, Pb and Mn, respectively. Results were confirmed by AAS and XRF.
Metals, trace Zinc Copper Nickel Lead Manganese HPIC Spectrophotometry Multidetection Post-column derivatization Method comparison Simultaneous analysis

"Continuous-flow-through Solid Phase Spectrophotometric Determination Of Trace Amounts Of Zinc"
Anal. Chim. Acta 1998 Volume 375, Issue 1-2 Pages 71-80
M. J. Ayora-Cañada, M. I. Pascual-Reguera and A. Molina-Díaz*

Abstract: A flow-through solid phase spectrophotometric sensing device for the determination of Zn(II) was developed based on the reaction of this ion with 1-(2-pyridylazo)-2-naphthol (PAN) immobilized on a Dowex cation exchanger placed in a flow-through cell. The reaction of Zn(II) with immobilized PAN and its retention on the resin developed the analytical signal. Adequate dissociation of the Zn-PAN complex left the unaltered reagent fixed on the solid support, enabling the regeneration of the sensor. The sensor allows working with several calibration Lines simply by varying the sample volume injected for the determination. As an example, linear dynamic ranges from 0.2 to 4.0 µg mL-1 and from 20 to 500 µg L-1 can be obtained by using 100 and 2000 µl, respectively, with detection limits being 0.05 µg mL-1 and 5 µg L-1, respectively. The RSD (%) being 2.1 (100 µl) and 2.3 (2000 µl) and the sampling frequency 38 and 15 samples per hour, respectively. The sensor was applied to the determination of Zn(II) in real samples, namely, human hair, pharmaceutical and cosmetic preparations and water samples.
Zinc Spectrophotometry Optosensing Solid phase detection Linear dynamic range

"Determination Of Cadmium In Biological Materials By Flame Atomic Absorption Spectrometry With Flow Injection Online Sorption Preconcentration"
Talanta 1994 Volume 41, Issue 12 Pages 2165-2172
Zhaolun Fang*, Shukun Xu, Liping Dong and Wenqing Li,

Abstract: A new on-line pre-concentration flame atomic absorption spectrometry (FAAS) system for trace element determination was developed based on sorption of soluble metal complexes on the walls of a PTFE knotted reactor using flow injection techniques. The system was applied to the determination of cadmium in biological materials. Cadmium complexed with sodium diethyldithiocarbamate was sorbed on the inner walls of the reactor and eluted on-line by isobutyl methyl ketone. The retention efficiency was 81% at a sampling loading rate of 5.2 ml/min. The enhancement factor was 66 and the concentration efficiency was 61/min with a 50 sec pre-concentration period, consuming 4.2 mL sample. A detection limit of 0.1 µg/l. Cd (3s) was obtained with a sampling frequency of 55/hr. The precisions were 1.2% RSD for 20 µg/l. Cd (N = 11). Thiourea and ascorbic acid/phenanthroline were used to overcome interferences from copper and iron, respectively. The analytical results obtained for powdered rice and human hair standard reference materials were in good agreement with the certified values.
Cadmium Spectrophotometry Preconcentration

"Spectrophotometric Determination Of Iron With Ferrozine By Flow Injection Analysis"
Talanta 1997 Volume 44, Issue 10 Pages 1793-1801
M. I. Pascual-Reguera*, I. Ortega-Carmona and A. Molina-Díaz

Abstract: Two methods for the determination of iron by normal FIA and reversed FIA were developed using sodium 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-4',4''-disulfonate (ferrozine). The reagent formed a chelate with Fe(II) in hexamethylenetetramine buffered medium at pH 5.5. In one previous reaction coil Fe(III) was reduced to Fe(II) by ascorbic acid and in the other reaction coil the complexation reaction was developed. The linear range of the determination was 0.5-6 and 0.1-5 µg mL-1 of iron for normal FIA and reversed FIA respectively. The proposed method was sensitive (detection limit 0.012 and 0.010 µg mL-1), rapid and reproducible (RSD 0.3 and 0.28%). The method was satisfactorily applied to the determination of iron in waste water, toadstool tissue, potato leaves, human hair and bauxites at a sampling rate of 90 and 50 samples h-1 for normal FIA and reversed FIA respectively.
Iron Spectrophotometry Reverse Sensitivity

"Simultaneous Determination Of Iron And Zinc By PH Gradient Construction In A Flow Injection System"
Talanta 1998 Volume 46, Issue 5 Pages 845-850
Shulin Zhao*, Xinquan Xia, Gang Yu and Bo Yang

Abstract: A flow injection method for the simultaneous determination of Fe and Zn in the human hair with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) using a pH gradient technique has been developed. The linear range for the determination of Fe is 0.1 ~ 1.8 µg/mL and for Zn is 0.2 ~ 5.0 µg/mL. About 20 ~ 30 samples can be determined in 1 h. The proposed method is simple, rapid and accurate. It has been applied to the simultaneous determination of trace amounts of Fe and Zn in the human hair with satisfactory results.
Iron Zinc Spectrophotometry pH gradient Gradient technique Simultaneous analysis

"Arsenic In Ground Water In Six Districts Of West Bengal, India: The Biggest Arsenic Calamity In The World. 2. Arsenic Concentration In Drinking Water, Hair, Nails, Urine, Skin-scale And Liver Tissue Of The Affected People"
Analyst 1995 Volume 120, Issue 3 Pages 917-924
Dipankar Das, Amit Chatterjee, Badal K. Mandal, Gautam Samanta, Dipankar Chakraborti and Bhabatosh Chanda

Abstract: Hair (0.5-1 g) and nails (0.5 ng) were digested with HNO3 at 90-100°C for 5 min. Concentrated HNO3 was added and the solution was evaporated to 1 mL and diluted to 5 mL. Urine (1 ml) was heated with HNO3 and HClO4 until fumes were evolve and thus the flow injection thermospray system can be used over wide analytical ranges. Solutions containing up to 2% of NaCl could be injected without plugging of the thermospray vaporizer capillary.
Arsenic, total Arsenate ion Arsenite Dimethylarsinic acid monomethylarsonic acid Sample preparation Spectrophotometry

"Chemiluminescence Flow System For Vanadium(V) With Immobilized Reagents"
Analyst 1997 Volume 122, Issue 7 Pages 685-688
Wei Qin, Zhujun Zhang and Chengjie Zhang

Abstract: A portion (0.19 mL) of 0.05 M H3PO4 was injected into an aqueous carrier stream (2.5 ml/min) and passed through a column of anion-exchange resin containing immobilized luminol and hexacyanoferrate(II) (preparation described). The eluate from the column was mixed with the sample stream (1 ml/min), which had previously been passed through a cation-exchange column to remove interfering ions. The resulting solution was merged with a stream (2.5 ml/min) of 0.2 M NaOH and the chemiluminescence produced was measured. A diagram of the manifold used is given. The calibration graph was linear for 0.01-10 µg/ml V(V), the detection limit was 5.4 ng/ml and the RSD (n = 7) was The throughput was 60 samples/h. The method was applied to geochemical materials and hair. A chemiluminescence (CL)-based system for vanadium(v) combined with flow injection analysis is described. The analytical regents, luminol and hexacyanoferrate(II), were both immobilized on an anion-exchange resin column. When a volume of phosphoric acid was passed through the column, these two reagents were eluted from the resin and then mixed with a vanadium(v) stream under acidic conditions. By means of the fast oxidation reaction between vanadium(v) and hexacyanoferrate(II), vanadium(IV) and hexacyanoferrate (III) were generated, both of which catalyzed the oxidation of luminol by dissolved oxygen in aqueous alkaline solution to produce CL. The CL emission intensity was correlated with the standard vanadium (v) concentration in the range from 1.0 x 10^-2 to 10 µg mL-1, and the detection limit was 5.4 x 10^-3 µg mL-1 vanadium(V). Interfering metal ions co-existing in sample solutions could be effectively separated on-line by a cation-exchange column placed upstream. A complete analysis, including sampling and washing, could be performed in 1 min with a relative standard deviation of less than 5%. The system was stable for over 100 analyzes and was applied successfully to the determination of vanadium in geochemical and human hair samples.
Vanadium(V) Ion exchange Chemiluminescence Immobilized reagent Resin Interferences Indirect

"Electrothermal Atomic Absorption Spectrometric Determination Of Molybdenum In Water, Human Hair And High-purity Reagents With Flow Injection Online Coprecipitation Preconcentration"
J. Anal. At. Spectrom. 1995 Volume 10, Issue 8 Pages 533-537
Hengwu Chen, Shukun Xu and Zhaolun Fang

Abstract: Hair (0.1 g) was digested with 5 mL 70% HNO3 and 1 mL 70% HClO4 on a sand-bath at 120-150°C to near-dryness. After cooling, the residue was dissolved in 5 mL 4 M HCl and 5 mL Fe(II) solution (500 mg/l) containing 2% ascorbic acid (sufficient to reduce any trivalent Fe present) was added. The solution was diluted to 50 mL with water and portions were injected into a stream of 0.4 M HCl (1.7 ml/min) of a flow injection system (schematic shown) and mixed with a stream of 0.25% ammonium pyrrolidinedithiocarbamate solution (0.3 ml/min). The precipitate formed [Mo-Fe(II) pyrrolidinedithiocarbamate] was collected on the walls of a knitted reactor and dissolved in 50 µL MIBK. The MIBK concentrate zone was directly introduced into the GF (program details given) with Ar carrier gas (300 ml/min) and the absorbance was measured at 313.3 nm for Mo by AAS. The detection limits were 0.04 and 0.02 µg/l of Mo, respectively, for a 30 and 60 s loading times. RSD was 3.1% at 1.3 µg/l of Mo and recoveries of spiked Mo in tap water, seawater and sodium chloride reagent were 94-104%. Results obtained from the analysis of Mo in a human hair certified reference material agreed well with the certified value.
Molybdenum Spectrophotometry Coprecipitation MIBK Preconcentration Reference material Knotted reactor

"Diagnostic Potential Of Hair Analysis As Applied To The Goldsmith Sector"
Microchem. J. 1998 Volume 59, Issue 1 Pages 32-44
S. Caroli, O. Senofonte, N. Violante, S. D'Ilio, S. Caimi, F. Chiodo and A. Menditto

Abstract: Trace elements were determined in hair of individuals involved in goldsmith activities in Italy. Three major areas of prodn. were selected: Arezzo, Valenza, and Vicenza. In total, 95 (73 exposed individuals and 22 controls) of the personnel employed in factories located in these provinces were examined Hair samples were collected, washed, and digested as prescribed by well-established procedures. Inductively coupled plasma mass spectrometry was employed for the determination of Ag, Au, Cd, Co, Cr, In, Ni, Pb, and Pt in the final solutions, whereas Hg was quantified by means of the flow injection mercury system. The expected high concentrations of Cu and Zn in the hair matrix, on the other hand, allowed the use of inductively coupled plasma atomic emission spectrometry. Certified Reference Material Human Hair (BCR CRM No. 397) was used throughout the study to check the accuracy of measurements. The geometric means obtained for exposed subjects were (µg/g) Ag, 1.293; Au, 1.445; Cd, 0.0369; Co, 0.017; Cr, 0.3270; Cu, 13.27; Hg, 1.510; In, 0.0016; Ni, 0.276; Pb, 0.662; Pt, 0.0036; and Zn, 172.3. For control subjects, on the other hand, the geometric means ascertained were (µg/g) Ag, 0.403; Au, 0.670; Cd, 0.0314; Co, 0.025; Cr, 0.2125; Cu, 11.08; Hg, 1.360; In, 0.0008; Ni, 0.467; Pb, 0.596; Pt, 0.0051; and Zn, 168.9. Statistical treatment of the data showed that the greatest difference between the values observed in exposed and unexposed subjects occurred for Ag, followed by Au, Cu, and In.
Silver Gold Cobalt Chromium Indium Nickel Lead Platinum Mercury Copper Zinc Mass spectrometry Spectrophotometry Spectrophotometry FIMS Reference material

"AAS Determination Of Trace Lead In Waters And Human Hair With Online Flow Injection Coprecipitation With Zinc Diethyldithiocarbamate As Carrier"
Fenxi Ceshi Xuebao 1997 Volume 16, Issue 1 Pages 25-29
Jin Jingchao, Chen Hengwu

Abstract: Hair (0.5 g) was digested with 10 mL of HNO3 and 1 mL of HClO4 by heating on a sand bath to near-dryness. The digest was dissolved in 4 mL of 6 M HCl with heating, and the solution was mixed with 5 mL each of 0.15% Zn(II) solution and 10% ascorbic acid and diluted to 50 mL with water. The solution was then submitted to online pre-concentration by diethyldithiocarbamate coprecipitation and flow injection GFAAS (flow diagram and procedure given). The detection limit was 2.7 ng/ml of Pd, and the RSD (n=11) was 1.3% at 200 ng/ml. The method was also used to determine Pb in water, with recoveries of 97-106%.
Lead Sample preparation Spectrophotometry Preconcentration Coprecipitation

"Co-catalytic Chemiluminescence System For The Determination Of Trace Amounts Of Copper(II) By Flow Injection Analysis"
Fenxi Huaxue 1989 Volume 17, Issue 10 Pages 922-924
Zhang, W.;Zhong, S.;Hu, H.;Gong, J.

Abstract: Water (50 ml) was acidified with 5 mL of concentrated H2SO4, evaporated to dryness and diluted with water to 50 mL. The pH of 5 mL of the solution was adjusted to 3 and the solution was diluted to 10 mL with water. A 100 µL portion of the solution was introduced into the flow injection analyzer. with 0.1 mM 1,10-phenanthroline - 15 mM NaOH - 5 mM hexadecyltrimethylammonium bromide - 1 M H2O2) reaction solution, water as carrier and chemiluminescence detection. Average recovery was 102% and the coefficient of variation was 0.9% for 10 ng mL-1 of Cu(II). The detection limit was 8 pg mL-1 and the calibration graph was rectilinear from 0.1 to 40 ng mL-1 of Cu. The method was also applied in determination of Cu(II) in human hair.
Copper(II) Chemiluminescence Catalysis

"Flow Injection Differential-kinetic Determination Of Lead With Meso-tetrakis(4-trimethylammoniumphenyl)porphyrin"
Fenxi Huaxue 1990 Volume 18, Issue 10 Pages 952-954
Mao, Q.K.;Zhang, C.;Cheng, J.K.

Abstract: Sample solution (170 µL) is mixed with 170 µL of the cited reagent (3 mM; I) each in carrier streams (1 mL min-1) of Na2B4O7 buffer solution (pH 10) in a reaction tube (15 m x 0.5 mm). The complex formed is detected at 465 nm vs. water. The working range was rectilinear up to 4 µg of Pb(II); the coefficient of variation was 0.3% for 1 µg of Pb and the sampling rate was 60 h-1. Tolerance levels of common ions are listed; there was little interference from Cd(II), Hg(II), Fe(III), Co(II), Ni(II), Zn(II), Cu(II) and Mn(II). The method was applied to the soaking extract of pottery and porcelain, and human hair.
Lead Spectrophotometry Sample preparation Kinetic Buffer pH Interferences

"Determination Of Trace Amount Of Cadmium And Lead In Human Hair Using A Flow Injection FAAS System With Online Preconcentration"
Huanjing Huaxue 1995 Volume 14, Issue 2 Pages 169-173
Chen, Shuyu; Zhang, Min; Lin, Shuqin; Peng, Zicheng

Abstract: A method to determine trace amounts of cadmium and lead in human hair was developed by coupling flow injection analysis with flame atomic absorption spectrometry (FAAS). In acidic solution, cadmium and lead are extracted into Methyl iso-Butyl ketone (MIBK) by ammonium pyrrolidinedithiocarbonate (APDC) in the extraction coil and detected by FAAS. The sensitivity of determination and sampling frequency may be improved greatly, while possible interferences may be effectively removed at the same time. The relative standard deviation was 3.4% (n=9) at 0.20 mg/mL. The sensitivity may be increased 21 times for Cd and 23 times for Pb. Cd and Pb recovery was 87.3%-97.0% and 91.9%-107.3%, respectively. Choices of experimental parameters were investigated; results obtained with some hair samples are consistent with literature values.
Cadmium Lead Spectrophotometry Preconcentration Interferences Extraction Organic solvent Optimization