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: Geological -> ore

Citations 34

"Determination Of Pd(II) By Application Of An On-line Microwave Oven And Artificial Neural Networks In Flow Injection Analysis"
Anal. Chim. Acta 2000 Volume 420, Issue 1 Pages 123-131
Sun Gang, Chen Xingguo, Zhao Yunkun, Liu Mancang and Hu Zhide

Abstract: A new methodology based on the coupling of an on-line microwave oven, employed to accelerate low-rate reactions, and artificial neural networks (ANNs), applied to the modeling and optimization of a new flow injection system, is proposed. In comparison with traditional heating, a microwave can accelerate low-rate reactions more remarkably and consume less energy. ANNs with a faster back-propagation (BP) algorithm are applied to model the system. Optimum experimental conditions are generated automatically by using jointly ANNs and optimization algorithms in terms of sensitivity, sampling rate and the energy consumed by a microwave oven. The methodology is tested on a new flow injection system for the spectrophotometric determination of Pd(II) with chlorophosphonazo-p-Cl (CPA-pC) in H2SO4 media, which has first been used as chromogenic reagent in the quantitative analysis of palladium. It is shown that the methodology can improve the ability of optimization, reduce analytical time, enhance sensitivity and consume less energy in comparison with traditional methods.
Palladium(II) Spectrophotometry Neural network Optimization Microwave Heated reaction Interferences Reference material

"Spectrophotometric Determination Of Uranium(VI) With 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol In A Flow Injection System"
Anal. Chim. Acta 1985 Volume 169, Issue 1 Pages 109-115
Elaine Anne Jones

Abstract: The sample was injected into a stream of 2% of cyclohexane-1,2-diamine-NNN'N'-tetra-acetic acid, 0.5% of NaF and 2% of ethanolamine in aqueous ethanol (pH 8.5 to 9.5) and mixed with 0.01% 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol solution in ethanol in a 4-m reaction coil. The absorbance of the complex formed was measured at 578 nm. The calibration graph was rectilinear for 0.5 to 20 mg L-1 of U(VI); the coefficient of variation (n = 12) was 1.9% for 10 mg L-1 of U(VI) in a synthetic leach liquor.
Uranium(VI) Spectrophotometry

"Segmental Flow Injection Analysis: Device And Applications"
Anal. Chim. Acta 1990 Volume 238, Issue 1 Pages 183-190
Li-Ching Tian, Xiao-Ping Sun, Yi-Yun Xu and Zheng-Liang Zhi

Abstract: The cited system possesses features of both flow injection and continuous-flow analysis. The sample zone is segmented by only two air bubbles and contained a valve designed so that sample and bubbles could be quantitatively injected into the carrier stream. The system provided residence times of >10 min at temperature up to 95°C without loss of peak height or sampling frequency, and owing to good reproducibility, analysis could be carried out before the equilibrium state was reached. The method was demonstrated by the determination of amino-acids in tea with the ninhydrin reagent, giving recoveries from 97 to 106%, a limit of detection of 5 mg L-1 and a coefficient of variation (n = 3) of 2.8%. Other applications included determination of ammonium and V in water, Cu in ores and creatine in urine.
Ammonium Vanadium Copper Creatine Detection limit

"Determination Of Gold In Ore By Flame Atomic Absorption Spectrometry With Flow Injection Online Sorbent Extraction Preconcentration"
Anal. Chim. Acta 1991 Volume 245, Issue 1 Pages 7-11
Shukun Xu, Lijing Sun and Zhaolun Fang

Abstract: A section of plastic Eppendorf pipette tip, measuring 0.6 and 5.0 mm i.d. at the lower and upper ends, respectively, was packed tightly (~2 cm) with Amberlite XAD-8 resin (25 to 50 mesh) (~220 µL). The column was fitted in the flow injection manifold such that adsorbed complexes were collected mainly at the narrower end and eluted from the broader to the narrower end. Samples (10 g) were heated (570°C, 30 min) in a muffle and then digested (50 min) in boiling 1:1 aqua regia (80 ml). After evaporation almost to dryness, concentrated HCl (10 ml) was added and brought to the boil. After cooling, the leachate and undissolved residue were made up to 250 mL with water. The complexes formed were adsorbed on the XAD-8 resin (7.6 mL min-1) and, after 40 s, adsorbed analyte was eluted with aqueous 95% ethanol (3.6 mL min-1) into the nebulizer and flame for determination by AAS (242.8 nm). The calibration graph was rectilinear up to 0.5 µg mL-1 and the detection limit was 2 ng mL-1 in the leachate, corresponding to 0.05 mg kg-1 in the ore. The coefficient of variation (n = 11) was 1.4% at 0.25 µg mL-1 for a single digest solution; the overall coefficient of variation was 3 to 5%. Recoveries of known amounts added to samples were 97 to 107%. The sampling rate was 60 h-1.
Gold Sample preparation Spectrophotometry Sample preparation Column Extraction Heated reaction Nebulizer Preconcentration Resin Amberlite

"Determination Of The Flotation Collector Ethyl Xanthate By Flow Injection Analysis"
Talanta 1990 Volume 37, Issue 11 Pages 1067-1070
Miloslav Kopanica, Vra Stará and Antonín Trojánek

Abstract: A flow-through cell suitable for voltammetric detection was constructed from Plexiglas (diagram given) containing a carbon-paste disc working electrode of silica gel - ceresine - graphite (14:43:43) and a Ag - AgCl reference electrode. Sample solution containing ~5 mg L-1 of K ethylxanthate was injected into the carrier stream of 0.1 M KNO3 (0.6 mL min-1) and voltammetric scanning (0.5 V s-1) was performed from -0.15 V to +0.9 V. Calibration graphs were rectilinear for 0.1 to 10 mg L-1 of ethylxanthate. The detection limit was 0.4 mg l-1. Interference from cations was overcome by addition of EDTA. The method was successfully applied to the analysis of ore.
Ethyl xanthate Voltammetry Electrode Flowcell Calibration Interferences Detection limit EDTA

"Flow Injection Fluorimetric Determination Of Thiamine And Copper Based On The Formation Of Thiochrome"
Talanta 1992 Volume 39, Issue 8 Pages 907-911
T. Perez-Ruiz*, C. Martinez-Lozano, V. Tomas and I. Ibarra,

Abstract: Thiamine solution was injected into a stream of Cu2+ solution (2.8 mL min-1), which was then passed through a 1-m reaction coil, mixed with phosphate buffer solution (0.9 mL min-1) and passed through a second 1-m coil at 30°C. The thiochrome formed was detected fluorimetrically at 465 nm (excitation at 370 nm). Rectilinear calibration was obtained for 0.3 to 6.0 µg mL-1 of thiamine or, by injection of a standard volume of thiamine solution, for 0.5 to 5.0 µg mL-1 of Cu. The method was applied to the determination of thiamine in pharmaceuticals and of Cu in alloys and ores. Other vitamin B components interfered with the determination of thiamine, and other transition metals with that of Cu; I- interfered in both methods. The reaction, involving the oxidation of thiamine by copper(II) in basic solutions to fluorescent thiochrome, has been adapted to the determination of thiamine by flow injection analysis Linear calibration graphs are obtained between 0.30 and 6.02 µg/mL with a sampling rate of 50 samples/h and a relative standard deviation of 0.53%. This reaction has also been adapted to the determination of copper(II) over the range 0.5-5.0 µg/mL. The applicability of both methods for determination of thamine and copper is demonstrated by investigating the effect of potential interferences and by the anal. of real samples (pharmaceuticals for thiamine and ores and allows for copper).
Thiamine Copper Fluorescence Heated reaction Interferences

"Design Of An Online Flow Injection System With A Gravitational Phase Separator For Flame Atomic Absorption Spectrometry And Its Analytical Performance"
Talanta 1993 Volume 40, Issue 7 Pages 1077-1083
Soulin Lin and Hwiping Hwang

Abstract: The design, construction and operation are described of an online phase separator for use in liquid-liquid extraction systems with segmented flows. The performance of the system was evaluated in the determination of Cu and Au by flame AAS after extraction into methylisobutyl ketone as their thiocyanate and trichloro- complexes, respectively. In each instance the calibration graph was rectilinear for 50 µg/l and the limits of detection were 1 and 1.8 µg/l for Cu and Au, respectively. For 10 µg/l the RSD were 1.8 and 2.5% for Cu and Au, respectively. Results for Au and Cu in standard ores were in good agreement with certified values.
Copper Gold Spectrophotometry Phase separator Reference material

"An Optimized Online Preconcentration System For Analysis Of Trace Gold In Ore Samples"
Talanta 1995 Volume 42, Issue 8 Pages 1081-1088
P. Di and D. E. Davey*

Abstract: A flow injection online pre-concentration technique, combined with GFAAS for the determination of Au in ore samples is presented. A 2 g ore sample was heated at 600°C for 3 h. After cooling, 20 mL aqua regia (1:1) was added and the mixture was boiled for 1 h with stirring. The sample was filtered and diluted to 100 mL. The sample was pre-concentrated using an α-amino pyridine resin microcolumn (5 cm x 3 mm i.d.) and a solution of acetone/HCl/H2O (18:1:1) was used for the Au elution. The Scaled Simplex Method was employed to optimize the flow injection manifold. The selected factors were optimized by the simultaneous consideration of two responses, absorbance and column retention efficiency. The calibration graph was linear up to 5 µg/l and the detection limit was 0.065 µg/l. The RSD was 4.3%.
Gold Spectrophotometry Preconcentration Optimization Simplex

"Flow Injection Spectrophotometric Determination Of Calcium Using Murexide As A Color Agent"
Talanta 1998 Volume 46, Issue 6 Pages 1245-1257
Kate Grudpana,*, Jaroon Jakmuneea, Yuthsak Vaneesorna, Surasak Wataneska, U Aye Maung, a and Ponlayuth Sooksamitib

Abstract: FI spectrophotometric determination of Ca using murexide was developed. The problem of the color of the dye fading and/or its complex in an alkaline medium in the batch method can be overcome by taking advantage of FIA. A Ca solution is injected into an ethylenediamine-ethylenediamine hydrochloride buffer (1 M, pH 11) which also serves as a masking agent, and is then merged with the aqueous murexide (0.005%, wt./v) and continuously monitored. Simple FIA manifolds, including an LED colorimeter detector hooked up to a PC-based data acquisition and evaluation system are described. Optimization of FIA systems was made. The proposed procedures were validated by using reference materials and comparing the results with the standard methods, and then applied to ores and drug samples.
Calcium Spectrophotometry Buffer Light emitting diode Computer Optimization Method comparison

"Flow Injection Spectrophotometric Determination Of Selenium Based On The Catalysed Reduction Of Toluidine Blue In The Presence Of Sulfide Ion"
Analyst 1989 Volume 114, Issue 6 Pages 715-717
Carmen Martinez-Lozano, Tomás Pérez-Ruiz, Virginia Tomás and Concepción Abellán

Abstract: A stream of 0.003% toluidine blue solution is mixed with a stream of alkaline 5 mM S2- containing 0.01 M BaNa2EDTA and 4% of formaldehyde (both 0.74 mL min-1), sample solution (80 µL) is injected into a carrier stream of aqueous 4% formaldehyde (0.74 mL min-1), and the two streams merge before passing to a 400-cm mixing coil. After 30 s, the flow stops for 30 s and the solution is pumped to a detector for absorbance measurement at 620 nm. The calibration graph is rectilinear for 0.2 to 2 µg of Se and the detection limit is 0.08 µg. The coefficient of variation (n = 11) for a 0.56 µg sample was 0.01%. The method was applied to ores and pharmaceuticals.
Selenium Spectrophotometry Catalysis Stopped-flow

"Application Of A Nested-loop System For The Simultaneous Determination Of Thorium And Uranium By Flow Injection Analysis"
Anal. Chem. 1989 Volume 61, Issue 15 Pages 1789-1791
Jose Luis Perez Pavon, Bernardo Moreno Cordero, Jesus Hernandez Mendez, and Rosa Maria Isidro Agudo

Abstract: The described system comprised a two-valve nested manifold, the loop of the nested (inner) valve containing a mini-column (5 cm x 2 mm) packed with Pb powder (0.1 to 0.3 mm). The injected sample (in carrier solution, 3.6 M HCl) is split into two portions, one passing through the reducing column, before mixing with the reagent stream (0.2 mM Arsenazo III in 3.6 M HCl, containing 1% Triton X-100). Complex formation was monitored at 665 nm. The detection limits were 123 nM-U and 94 nM-Th. The coefficient of variation for the second peak (corresponding to the reduced sample) were 2.1% for U and 0.9% for Th. Results for the simultaneous determination of U and Th in nine synthetic mixtures, and in a standard ore (pitchblende S-12) demonstrated that small amounts (0.09 ppm) of Th could be determined even in the presence of 16-fold amounts of U, and that the amounts U determined agreed with certified values.
Uranium Thorium-232 Spectrophotometry Nested loop Valve Triton X Complexation Reference material Surfactant

"Ion Chromatography Of Gallium, Indium And Thallium With Applications To The Analysis Of Ores"
Fresenius J. Anal. Chem. 1988 Volume 331, Issue 6 Pages 601-606
Daren Yan, Jingan Zhang und Georg Schwedt

Abstract: Gallium, In, Tl(III), Fe(III), Cu(II), Pb(II) and Zn were separated in 15 min by ion chromatography on a Nucleosil 10SA column (22 cm x 4.6 mm) with 0.1 M tartrate - 0.12% NaCl (pH adjusted to 2.25 with HCl) as mobile phase (1.1 mL min-1). After post-column derivatization with 1 mM 4-(2-pyridylazo)resorcinol - 0.5 mM ZnEDTA - 2 M NH3 at pH 11 and 60°C in a 6-m reaction coil, the metals were detected at 495 nm. Rectilinear calibration ranges varied from 0.08 to 8 ppm of Fe(III) to 0.4 to 40 ppm of Tl(III), Ga, In and Pb(II). A described procedure for the simultaneous determination of Ga and In in complex ores was applied to one synthetic and four natural samples, e.g., a silicate, containing 40 ppm to 0.1% of Ga and In. For determination of all seven metals in the synthetic sample the coefficient of variation were 2.8% (n = 7).
Copper(II) Indium Iron(III) Gallium Lead(2+) Thallium Zinc HPIC Spectrophotometry Heated reaction Post-column derivatization

"Computerized Flow Injection Potentiometric Stripping Analysis With Large-volume Wall-jet Cell"
Fresenius J. Anal. Chem. 1988 Volume 332, Issue 2 Pages 148-152
Wojciech Matuszewski, Marek Trojanowicz and Wolfgang Frenzel

Abstract: A flow injection system is described incorporating a large-volume wall-jet cell (diagram given) and a microcomputer for digital signal recording and data processing. The working electrode was a vitreous-carbon rod of 3 mm diameter pressed into PTFE. A SCE was used as reference electrode and platinum foil (1 cm2) was used as auxiliary electrode. The electrodes were immersed in 0.1 M HCl (carrier solution). The system was applied in the simultaneous determination of Cd and Pb in geological materials. Rock or ore (100 mg) was mixed with 5 mL of 40% HF and heated to dryness in a sand bath at 400°C. The residue was dissolved in 5 mL of 4% H3BO3 and the solution was diluted to 10 mL (rocks) or 50 mL (ore) with 0.1 M HCl. A 750 µL portion of solution was injected; the deposition time was 8 min at -1.15 V vs a SCE; the flow rate was 1.5 mL min-1. Potentiometric stripping was carried out under stopped-flow conditions by using 40 ppm of Hg(II) in 0.1 M HCl as oxidizing agent. Results agreed with those by AAS.
Cadmium Lead Potentiometric stripping analysis Electrode Electrode Computer Method comparison Stopped-flow

"Spectrophotometric Determination Of Uranium(VI) With Chlorophosphonazo-mN By Flow Injection Analysis"
Anal. Lett. 1994 Volume 27, Issue 10 Pages 1989-1998
Sun, J.Y.;Chen, X.G.;Hu, Z.D.

Abstract: Sample (100 µL) was injected into 0.3 M HNO3 (0.8 ml/min) and 0.298 mM chlorophosphonazo-mN (0.8 ml/min) passed through a mixer coil (12 cm x 0.5 cm i.d.) and together with 1% DTPA (0.8 ml/min) through a reactor coil (90 cm x 0.5 mm i.d.). The U(VI) - chlorophosphonazo-mN complex (1:2) was measured at 680 nm. Beer's law was obeyed for 1-15 µg/ml of U(VI). The detection limit was 0.5 µg/ml of U(VI). The sampling frequency was 60/h. In the presence of DTPA a large excess of the most common cations, with the exception of Ca(II), did not interfere with the determination of 3 µg/ml of U(VI); criterion for interference was ±5% deviation of the expected signal. The method was used to determine U(VI) in standard ores and the results (tabulated) agreed well with those obtained by the standard Arsenazo III method.
Uranium(VI) Spectrophotometry Interferences Method comparison Standard method

"Flow Injection Method For The Separation Of Thallium And Gold On A Sephadex Column And Their Extraction-photometric Determination With Rhodamine B"
Anal. Sci. 1990 Volume 6, Issue 3 Pages 421-424

Abstract: The method involves injection of a sample into 0.5 M HCl - 1 M LiCl as carrier solution (0.6 mL min-1), and passsage through a column (15 cm x 3 mm) of Sephadex G-25. The eluate is added to 0.04% rhodamine B (0.18 mL min-1), and the mixture is then mixed with benzene (0.2 mL min-1). After passage through a 2-m extraction coil and a phase separator, the absorbance of the organic phase is measured at 565 nm. The retention times for Tl and Au on the column are 5.5 and 11 min, respectively. From 0 to 5 mg L-1 of each metal can be determined. The method was applied to coal fly ash and ores. Recoveries were 97 to 98% for Tl and Au in the respective samples.
Thallium Gold Spectrophotometry Sample preparation Column Phase separator Organic phase detection Sephadex Solvent extraction Reference material

"Catalytic Spectrophotometric Determination Of Ruthenium By Flow Injection Analysis Using Amido Black 10B And KIO4"
Bull. Soc. Chim. Belg. 1992 Volume 101, Issue 12 Pages 989-994
Chen Xingguo, Hu Zhide and Zheng Hongwen

Abstract: A new method has been developed for the determination of trace ruthenium by flow injection analysis The proposed method is rapid, simple and sensitive. The method has a limit of detection for ruthenium 0.050 µg/mL and permits 60 determinations per h. The method has been applied to determine ruthenium in refined ore with satisfactory results.
Ruthenium Spectrophotometry Catalysis

"Studies On Flow Injection Analysis Of Platinum Metals. 3. Ruthenium(III) - Potassium Periodate - α-naphtholphthalein System"
Fenxi Huaxue 1989 Volume 17, Issue 3 Pages 212-216
Cai, Y.;He, X.;Chen, X.G.;Hu, Z.D.

Abstract: For determination of Ru in refined ore or chlorinated slag, a 1-g sample was fused successively with 4 g of Na2CO3 - MgO (3:1) and 7 g of Na2O2. The melt was extracted with water, the solution was acidified with H2SO4 (1:1) and, after addition of 20 mL of 30% H2O2, OsO4 was selectively distilled off. The residue was treated with 10 mL of saturated KMnO4 solution before distillation of RuO4, which was absorbed in a mixture of 10 mL of 12 M HCl and 0.2 mL of ethanol and then reduced to Ru(III) by NaBH4. The solution was diluted with water to 100 ml, and a 0.1 mL portion was injected into a carrier stream of water at 80°C to react with 1 mM KIO4 and 0.2 mM α-naphtholphthalein (I) in 0.2 M Na2B4O7 - 0.2 M NaOH buffer medium of pH 10; spectrophotometric detection was at 640 nm and involved measuring the discharge by Ru(III) of the color of the KIO4-oxidation product of I. Recoveries were 103 to 106%, the coefficient of variation was 0.8 to 1.1%, and the detection limit was 0.01 µg mL-1 of Ru(III). Up to 65 injections could be made in 1 h.
Ruthenium(III) Sample preparation Spectrophotometry Heated reaction Indirect

"Determination Of Palladium(II) By Direct Spectrophotometry And Flow Injection Analysis With 1,8-dihydroxy-2-[(4-chloro-2-phosphonic Phenyl)azo]-7-[(4-sulfonic Acid Amide Phenyl)azo]-3,6-disulfonic Acidic Naphthalene [3-(4-aminosulfonylphenylazo)-6-(4-chlo"
Fenxi Huaxue 1989 Volume 17, Issue 11 Pages 1033-1035
Chen, X.G.;Xu, Y.J.;Liu, M.;Hu, Z.D.

Abstract: For direct spectrophotometric determination, a portion of Pd solution (1 mg mL-1), was heated for 5 min, in a boiling water bath with 5 mL of 6 M H2SO4 and 0.5 mL of 1 mM of the cited reagent (I). The absorbance of the cooled solution was measured at 620 nm vs. a reagent blank. For flow injection analysis , Pd solution (100 µL) was injected over 10 s into a stream of aqueous 2% H2SO4 and reacted with 0.1 mM I and 2.5 M H2SO4 at 90°C, detection was at 620 nm; peak heights were used for quantitation. Beer's law was obeyed from 3 to 20 µg of Pd in 25 mL of solution when employing direct spectrophotometry, and 0.2 to 5 µg mL-1 of Pd for FIA with a detection limit of 0.1 µg mL-1. For analysis of 0.4 µg mL-1 of Pd, most foreign ions were tolerated. The method was applied in the analysis of ores. Recoveries were 93 to 104%.
Palladium(II) Spectrophotometry Heated reaction Interferences

"Air-segmented Flow Injection Determination Of Trace Copper(II) By Catalytic Kinetic Reaction"
Fenxi Huaxue 1991 Volume 19, Issue 10 Pages 1173-1175
Zhi, Z.L.;Tian, L.C.;Wu, Q.

Abstract: Sample (0.1 g) was treated with HCl and HO3, the pH of the solution was adjusted to 1 to 2 by 1 M NaOH and 1 M HCl and the mixture was heated at 90°C for 5 min with 0.2% hydrazine sulfate. The mixture was diluted to 25 mL with water and a portion (60 µL) of the solution was carried by a stream of water (0.8 mL min-1) to react with 1 mM Fe(III) sulfosalicyclate and 7.5 mM Na2S2O3 (both at 0.3 mL min-1) at 40°C for 2.2 min with detection at 505 nm. The calibration graph was rectilinear up to 4 µg mL-1 of Cu. Recovery was 97 to 106% with a coefficient of variation of 1.5% and a detection limit of 0.1 µg mL-1. Little interference was observed. Results are compared with those of flame AAS. The method was applied in the determination of copper in some ores.
Copper(II) Spectrophotometry Air segmentation Catalysis Heated reaction Interferences Kinetic Method comparison pH

"Determination Of Arsenic, Antimony And Bismuth By Inductively Coupled Plasma Atomic-emission Spectrometry With Flow Injection Analysis And Hydride Generation"
Fenxi Huaxue 1991 Volume 19, Issue 11 Pages 1285-1287
Gao, H.;Li, K.

Abstract: A 0.175-g ore or rock sample was wetted with a little water and then dissolved in 9 mL of HCl plus 3 mL of HNO3 and 1 mL of H2SO4 (1:1); after evaporation to fumes and cooling, 2.5 mL of HCl, 5 mL of 10% KI - 5% ascorbic acid - 5% thiourea solution and water were added to 25 mL. The solution was then carried at a flow-rate of 11 mL min-1 to react with 1% KBH4 solution (containing 0.2% of NaOH) at 5.5 mL min-1 in the flow injection system (diagram pesented), and the generated hydrides were carried by Ar (0.6 l min-1) for separation by a gas separator before passing to a direct-reading spectrometer for ICP-AES determination of As, Sb and Bi with measurement at 193.76, 217.5 and 306.7 nm, respectively. By the standard-additions method, recoveries were 94 to 107%. Determination ranges for As, Sb and Bi were up to 1000, 300 and 300 µg g-1, respectively, and their corresponding detection limits were 0.2, 0.2 and 0.1 µg g-1. Masking agents could be used to increase tolerance levels of the co-existing ions; background interferences in the gas phase could be corrected for.
Antimony Arsenic Bismuth Spectrophotometry Interferences Standard additions calibration

"Determination Of Trace Copper In Ores With Sodium Diethyldithiocarbamate By Flow Injection Extraction-spectrophotometry"
Fenxi Huaxue 1993 Volume 21, Issue 10 Pages 1168-1170
Zhao, H.Z.;Chen, S.Y.;Lin, S.Q.;Li, F.Q.

Abstract: Ore or steel was wetted with water, dissolved in aqua regia and diluted with water. A portion was mixed with 5% EDTA/20% trichloroacetic acid (mixed masking agent), then the solution was adjusted to pH 8.2 and diluted with water. Trace Cu(II) in the solution was determined by the cited method in a FIA system (diagram given) with CCl4 as extractant and 0.2% sodium diethyldithiocarbamate as color reagent. The absorbance was measured at 437 nm. Beer's law was obeyed up to 1.28 µg/ml of Cu. The RSD (n = 11) was 3.5%. The results for five reference standards agreed with their certified values.
Copper Spectrophotometry Sample preparation Reference material Extraction

"An Investigation Of Chemiluminescence Reaction In Luminol - Potassium Persulfate - Silver(I) - Triethylenetetramine System: Determination Of Trace Silver In Ores By Flow Injection Analysis"
Fenxi Shiyanshi 1986 Volume 5, Issue 9 Pages 4-7
Zhang Xinrong, Lu Jiuru, Yang Kun Zhang Zhujun

Abstract: Optimum concentration. in the flow analysis system were 75 mM for luminol, 40 mM for K2S2O8 and 0.02% of triethylenetetramine for production of chemiluminescence in alkaline solution (pH 13). The Ag was pre-separated from the ore sample by collection on mercaptoacetoxycellulose fiber. A rectilinear calibration graph was obtained over the range 10 ng mL-1 to 10 µg mL-1 of Ag with a coefficient of variation <4% (n = 11) at 0.1 µg mL-1. Of >20 foreign ions tested, serious interference was shown by Mg, Cd, Co and Mn only.
Silver Chemiluminescence Interferences Mercaptoacetoxycellulose fiber

"Studies On Flow Injection Analysis Automatic Dilution Techniques And Their Applications"
Fenxi Shiyanshi 1991 Volume 10, Issue 3 Pages 56-58
Lin, S.;Lu, L.;Li, Y.

Abstract: Three types of automatic dilution techniques, viz., small-volume injection sampling, sequental-injection zone sampling and sample splitting, were investigated, with regard to simplicity, flexibilty, dilution factors and precision. Dilution factors were from 50 (for small-volume injection sampling) to 1000 (for sample splitting). The techniques were highly efficient with excellent precision over a wide range of dilution. The sample-splitting method was applied to ores and electroplating solution; coefficient of variation were 0.3%.
Automation Dilution Precision Small sample Sample splitting Zone sampling

"Study On Applicability Of Trace Element Determination In Solution With High Salt Concentration By FIA-flame AAS"
Fenxi Shiyanshi 1993 Volume 12, Issue 4 Pages 19-22
Yuan, Y.;Guo, X.W.

Abstract: A pre-concentration system (schematic diagram given) was developed for flame AAS and applied to the determination of Pb in Cu metal, and Ag and Cd in geological samples. For determination of Ag and Cd in ore, sample (2 g) was digested with 10 mL of 1:1 aqua regia by heating, the solution was evaporated to ~5 ml, mixed with 0.5 mL of 1% gelatin before dilution with water to 10 mL. The solution was analyzed by the cited method with 1% aqua regia as carrier stream. The detection limits were 0.02 µg/g of Ag and 0.01 µg/g of Cd; RSD (n = 23) were 0.5%.
Lead Silver Cadmium Spectrophotometry Preconcentration

"Application Of 4-aminohippuric Acid Chlorophosphonazo In Determination Of Palladium(II) By Spectrophotometry And Flow Injection Analysis"
Huaxue Shiji 1990 Volume 12, Issue 1 Pages 12-14
Chen Xingguo Xu Yanjun Liu Mancang Hu Zhide

Abstract: Ore (0.2 g) is dissolved in 10 mL of aqua regia, evaporated to near dryness and further evaporated to near dryness with 2 mL of HCl prior to dilution with 10% HCl to 10 mL. For direct spectrophotometric determination, an aliquot of the solution is treated with 5 mL of 12N-H2SO4, 0.5 mL of 1 mM cited compound (N- 4-[7-(4-chloro-2-phosphophenylazo)-1,8-dihydroxy-3,6-disulfo-2-naphthylazo]benzoyl glycine; I) followed by heating in a boiling-water bath for 5 min, dilution to volume and measurement of absorbance at 631 nm (ε = 37,000) vs. a reagent blank. Beer's law is obeyed for 3 to 20 µg of Pd(II) in 25 mL of final solution For flow injection analysis, 100 µL of the solution is applied to the apparatus (diagram given) and flows to the reactor coil (at 90°C) with a stream of 2% H2SO4 to mix with 80 µM-I and then 5N-H2SO4 before measurement of absorbance at 631 nm; the sampling rate is 60 samples h-1. The calibration graph is rectilinear for 0.25 to 1.25 µg of Pd in 1 mL of solution The detection limit is 0.15 µg mL-1 and the coefficient of variation is 1% for 1 µg mL-1 of Pd. Interferences of 9 foreign ions in both methods have been studied.
Palladium(II) Sample preparation Spectrophotometry Dilution Detection limit Interferences Heated reaction

"Flow Injection Spectrophotometric Determination Of Ultra Trace Amounts Of Selenium(IV)"
Indian J. Chem. A 1997 Volume 36, Issue 1 Pages 105-107

Abstract: A schematic diagram of the FIA system is presented. Sample (250 µL) was injected into a water carrier and merged with 0.32 mM gallocyanine buffered at pH 7 by phosphate and 0.55 mM sulfide solution containing barium disodium EDTA. All reagents were pumped at 0.5 ml/min. The solutions were mixed in a 200 cm reaction coil and the decrease in absorbance of gallocyanine as a result of its catalytic (Se) reduction by sulfide was measured at 620 nm. The decrease in gallocyanine absorbance was proportional to the Se(IV) concentration from 2.5-500 ng/ml and the detection limit was 1 ng/ml. The RSD (n = 10) was 1.5% for 50 ng/ml of Se(IV). The method was applied to ores, personal care products and water. The interference effects of various ions on the determination were investigated.
Selenium(IV) Spectrophotometry Catalysis Detection limit Interferences Buffer Indirect

"Sorption-atomic Fluorescence Determination Of Gold In Ores"
J. Anal. Chem. 1998 Volume 53, Issue 7 Pages 672-678
L. V. Bogacheva, I. A. Kovalev, G. I. Tsizin, and Yu. A. Zolotov

Abstract: The sorption of gold from hydrochloric acid solutions with polyacrylate sorbents XAD-8, Spheron 1000, and Spheron 100000 is studied. The limiting stage of the metal sorption is diffusion to the sorbent grains for XAD-8 and mass transfer of the metal in solution for Spheron 1000 and Spheron 100000. Kinetic and thermodynamic parameters of sorption are determined. Based on the studies and calculations, the XAD-8 polymer is selected as the most efficient sorbent for the pre-concentration of gold. A microcolumn with the sorbent is used in a flow injection system for the pre-concentration of gold in the sorption-desorption mode. 106-108-Fold quantities of Fe, Cu, and Al do not decrease the recovery of gold from solutions A highly sensitive method is developed for the determination of gold in ores; the method includes the acid decomposition of a sample and the flow sorption-atomic fluorescence determination of gold in the solution. With pre-concentration for 2 min, the detection limit of the metal is 1.2 x 10^-6%. The method exhibits high precision (relative standard deviation = 1-6% in a wide range of determined metal concentrations). High accuracy of gold determination in ores was confirmed by the analysis of standard reference samples of ores.
Gold Fluorescence Column Resin Preconcentration Interferences Reference material

"Flow Injection Analysis - Oxidation - Reduction Titration Of Iron"
Lihua Jianyan, Huaxue Fence 1991 Volume 27, Issue 6 Pages 361-362
Chen, J.;Ma, Q.

Abstract: A method for the determination of Fe was developed and applied in the analysis of ores. Sample was wetted with a little water, dissolved in concentrated HCl and heated with 4 M H2SO4. Following dilution with water, a portion of the solution was injected into a flow injection manifold into a stream of 0.5 M H2SO4 containing 0.008% sodium diphenylamine-4-sulfonate (1.3 mL min-1) which passed through a Jones' reduction column (12 cm x 3 mm) packed with zinc amalgam. The mixture was allowed to react with a stream of 0.16 mM K2Cr2O7 containing H2SO4 and H3PO4 (1.3 mL min-1) as titrant and the absorbance of the resulting mixture was monitored at 550 nm. The calibration graph was rectilinear for 7.3 to 60.8 mM Fe, the average recovery was 105% and the coefficient of variation was 0.43%. Sample throughput was 10 to 12 h-1.
Iron Spectrophotometry Heated reaction Jones reductor Reduction column Titrations

"Study On The Flow-injection Analysis (FIA)-chemiluminescence Determination Of Zirconium(IV) Based On A Coupled Reaction"
Lihua Jianyan, Huaxue Fence 1998 Volume 34, Issue 11 Pages 486-489
Li Weihua, Li Jianzhong and Zhang Zhujun

Abstract: A new method for the FIA-chemiluminescence (FIA-CL) determination of Zr(IV) based on coupled reaction was presented. Co(II) in Co(II)-nitrilotriacetic acid (NTA) complex was replaced by Zr(IV) quantitatively, and the obtained Co(II) can catalyze the chemiluminescence of the oxidation of luminol by H2O2. The CL-intensity was in linear relation with the concentration of Zr(IV) at 1 x 10^-10 - 1 x 10^-7 g/mL, the detection limit was 3 x 10^-11 g/mL, and the relative standard deviation 2%. The existence of Cr(III), Fe(III), and Cu(II) interfered in the determination The method was used for the determination of Zr(IV) in ores with the relative standard deviation 4-5%, and the results were consistent with the reference values.
Zirconium(IV) Chemiluminescence Indirect Interferences

"Advances In Online Particulate Composition Analysis"
Powder Technol. 1992 Volume 69, Issue 1 Pages 93-99
Harrison R. Cooper

Abstract: A review is presented, with 32 references, of techniques including X-ray diffraction, XRF, prompt NAA, magnetic resonance methods and flow injection spectrophotometry in online analysis of bulk powdered solids, e.g., ores and coals. Measurements required to define properties of particulate materials include size, composition and density among the important variables. In managing a particulate-related process, one or more of these variables would be significant to defining control parameters for materials being treated in the process. Therefore, inspection methods for size, composition and density are of particular interest. Advances in methods employed for inspection are reviewed from the standpoint of establishing particulate composition data. Principle attention is given to on-line automated procedures adaptable for use with controls.
Spectrophotometry Review

"Construction Of Flow-through Ion-selective Electrodes And Their Use In Flow Injection Analysis. Potentiometric Determination Of Gold(III)"
Quim. Anal. 1988 Volume 7, Issue 3 Pages 311-321
Ortuno, J.A.;Torrecillas, M.C.;Sanchez Pedreno, C.

Abstract: A 1-mm portion of a 2-cm length of plastic-coated tinned copper wire is immersed for 1 min in 0.01 M HAuClO4 in 0.1 M HCl. It is then repeatedly (~20 times) dipped into a solution containing 0.1 g of PVC, 0.1 g of dibutyl phthalate and 10 mg of 1,2,4,6-tetraphenylpyridinium tetrachloroaurate in 2 mL of THF. The resulting electrode is fitted into a polymethacrylate flow mini-cell (illustrated) for use as a potentiometric detector (in conjunction with a double-junction reference SCE) in a flow injection system. The electrode is conditioned with 0.1 M HCl and 10 µM-HAuCl4 in 0.1 M HCl. Response is rectilinear for 1 µM to 10 mM Au(III), and the detection limit is 0.3 µM. Sampling rate is 115 h-1 for 10 µM-Au. Of 23 foreign ions tested, only Tl(III) and Sb(V) interfere. The system has been successfully applied in the determination of Au (0.3 g t-1) in ores; samples were decomposed with aqua regia, solution in 1.4 M HCl were extracted with ethyl ether, the extracts were evaporated and the residues were dissolved in 0.1 M HCl for analysis.
Gold(3+) Electrode Electrode Potentiometry Sample preparation Apparatus Interferences

"Flow Injection Catalytic Photometric Determination Of Trace Iodine In Rock And Ore Samples"
Yanshi Kuangwuxue Zazhi 1983 Volume 2, Issue 4 Pages 314-315
Li Kaiyuan, Hua Ping

Abstract: Trace iodine in rock and ore samples was determined by a photometric method based on the reaction 2Ce4+ + As3+ (orange-red) -> 2Ce3+ + As6+ (colorless) catalyzed by ions. The reaction was carried out in a flow injection analyzer with a detection limit of 8 ppb. Thus, a rock sample 0.5 g was added to 1N H2SO4, heated in a boiling water bath for 30 min with vigorous shaking, an aluminum potassium sulfate solution (7 g/100 mL H2O) 1 mL added, and diluted to 10 mL with 1N H2SO4. A 63 mL portion of the sample solution was analyzed in a flow injection analyzer containing sodium arsenite and Ce(SO4)2 solutions at 37°C and 420 nm. Iodine was determined in an apatite sample to be 0.0030%.
Iodine Spectrophotometry Catalysis Heated reaction

"Determination Of Micro Bismuth In Ores By Hydride Generation-electrothermal Atomic Absorption Spectrometry Combined With Flow Injection Analysis"
Yejin Fenxi 1998 Volume 18, Issue 4 Pages 49-50
Yang, Yi

Abstract: A method for the determination of µBi in ores by hydride generation-electrothermal AAS combined with FIA was presented. The determining wavelength was 306.7 nm. Thiourea, ascorbic acid, and KI were used as masking agents. The method was applied to determine Bi in ores with the RSD 2.4-3.9%.
Bismuth Spectrophotometry Spectrophotometry Volatile generation Interferences

"Spectrophotometric Determination Of Microamount Of Gold By Flow Injection Analysis"
Youkuangye 1988 Volume 7, Issue 4 Pages 24-28
Liu Shaorun Xia Buyun

Abstract: A new method of the determination of microamount of gold is established and presented in this paper. The method has been used in the assay of gold in ores (containing gold 0.x to xx g/t) with a RSD of 15%. After the sample solution has passed through the CL-5209 extractant-containing resin column, almost all the coexisting ions in common ores do not interfere the determination. The standard calibration curve ranges over 0.05 -0.3 µg/mL with correlation coefficient of 0.999. Sixty samples can be determined each hour by this method.
Gold Spectrophotometry Triton X Interferences Resin