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
Email: schalk@unf.edu
Website: @unf

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Gui B. Jiang

Abbrev:
Jiang, G.B.
Other Names:
Gui Bin Jiang, Guibin Jiang, Jiang Gui-bin
Address:
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China
Phone:
+86-10-62849124
Fax:
+86-10-62923563

Citations 18

"Evaluation Of A Reagent-injection Flow Injection Technique For Sample Background Absorption Elimination: Determination Of Chloride In Cigarettes"
Talanta 2001 Volume 54, Issue 2 Pages 329-332
Liu Jing-fu and Jiang Gui-bin

Abstract: The applicability of reagent-injection flow injection (FI) technique in elimination of background absorption was evaluated by using the FI determination of water-soluble chloride in cigarettes, based on the mercury thiocyanate method, as a model. Some parameters of the proposed reagent-injection FI method were optimized and the proposed procedure had a linear range of 0-7.5 mg L-1 Cl, a detection limit of 0.02 mg L-1 Cl, a sampling rate of 60 h-1 and a relative standard deviation of 0.1% at 5 mg L-1 Cl. Eight cigarette samples were analyzed by this proposed reagent-injection Fl method and the referential membrane dialysis Fl procedure. The relative errors were < 4.3%, and paired c-test shows that there are no significant differences between these two methods. As no dialysis unit was needed, the reagent-injection FI method has much simpler flow system than the existed CFA and FI methods. (C) 2001 Elsevier Science B.V. All rights reserved.

"Selective Determination Of Orthophosphate And Total Inorganic Phosphates In Detergents By Flow Injection Photometric Method"
Talanta 2000 Volume 52, Issue 2 Pages 211-216
Liu Jing-fu and Jiang Gui-bin

Abstract: A flow injection photometric system was developed for the determination of orthophosphate and total inorganic phosphates in detergents. While orthophosphate was directly determined in the presence of other phosphates by utilizing the kinetic discrimination of flow injection analysis, total inorganic phosphates was analyzed after on-line hydrolysis of polyphosphates in 2.5 mol L-1 sulfuric acid for 50 s under 145°C. Sodium dodecyl sulfate (SDS) was added to mask the interference of non-ionic surfactants. The detection limits and the sampling rates were 2.5 mg L-1 P2O5 and 40 h-1 for total inorganic phosphates, and 1.0 mg L-1 P2O5 and 80 h-1 for orthophosphate determination. The proposed method was applied to analyze orthophosphate and total inorganic phosphates in washing powders. The experimental results are in good agreement with those obtained by the Chinese national standard methods.

"Distributions Of Arsenic And Selenium In Selected Chinese Coal Mines"
Sci. Total Environ. 2002 Volume 296, Issue 1-3 Pages 19-26
Bin He, Lina Liang and Guibin Jiang

Abstract: The contents of arsenic and selenium in 33 coals collected from the main coal mines in northeastern, northern and eastern China were determined by flow injection-hydride generation and non-dispersion atomic fluorescence spectrometry (HGAFS). The concentrations of As in the northeast region are relatively higher with the values >100 µg g-1; in the east they are lower with values <100 µg g-1. The contents of Se in these three areas are the opposite, most of them from the northeast mines are < 1 µg g-1 and increase as the mine location advances south where the average contents are >5 µg g-1. (C) 2002 Elsevier Science B.V. All rights reserved.

"Optimization Of The Extraction For The Determination Of Arsenic Species In Plant Materials By High-performance Liquid Chromatography Coupled With Hydride Generation Atomic Fluorescence Spectrometry"
Spectrochim. Acta B 2002 Volume 57, Issue 11 Pages 1705-1711
Bin He, Yu Fang, Guibin Jiang and Zheming Ni

Abstract: A study has been conducted for the separation and the determination of arsenic species in plants using high-performance liquid chromatography-hydride generation atomic fluorescence spectrometry with emphasis on sample extraction procedures. Various extraction solvents have been applied to extract arsenic species from plants in order to investigate the uptake, transfer and accumulation processes of arsenic. The method was optimized with respect to the selection of extraction solvent, extraction time and the number of extraction steps. The analytical procedure has been validated by analyzing standard reference material GBW 82301, (peach leaves) and successfully used for the arsenic speciation in plants grown on contaminated soil near an arsenic mine. Inorganic arsenic, especially arsenate (As(V)) appears to be the major component in plants and organic arsenic species of monomethylarsenic acid and dimethylarsenic acid were detected at low concentrations. (C) 2002 Elsevier Science B.V. All rights reserved.
Speciation

"Determination Of Anionic Surfactants In Detergents By Microporous Membrane Liquid-liquid Extraction And Flow Injection Spectrophotometry"
Microchem. J. 2001 Volume 68, Issue 1 Pages 29-33
Liu Jing-fu and Jiang Gui-bin

Abstract: The applicability of microporous membrane liquid-liquid extraction (MMLLE) and flow injection spectrophotometry to the determination of anionic surfactants in detergents was studied. Optimization of variables of the flow injection manifold, groove length of the MMLLE unit, and pore size of the membrane was performed. Experiments showed that the long-term reproducibility of the system was limited when the peristaltic pump and the displacement bottle arrangement were used, but the system was still applicable in routine analysis if calibration was carried out every 20 min. The proposed method has a linear range of 0.2-2 mmol L-1 sodium dodecylbenzenesulfonate (DBS) and a detection limit (S/N=3) of 0.1 mmol L-1 DBS. The sampling rate was 50 h-1 and the relative standard deviation was 1.8% (n=11) at 1.0 mmol L-1 DBS level. Eleven washing powder samples were analyzed with the proposed procedure and the standard Epton method, and paired t-tests showed that there is no significant difference between these two methods.

"Identical Flow Injection Spectrophotometric Manifold For Determination Of Protein, Phosphorus, Calcium, Chloride, Copper, Manganese, Iron, And Zinc In Feeds Or Premixes"
J. AOAC Int. 2001 Volume 84, Issue 4 Pages 1179-1186
Jing-Fu Liu, Ying-Di Feng, and Gui-Bin Jiang

Abstract: A simple procedure using an identical manifold was developed for determination of nitrogen (protein) phosphorus, calcium, chloride, copper, manganese, iron, and zinc in feeds and feedstuffs. By changing appropriate reagents and detection wavelength, these 8 elements were determined successively with a simple identical double-line flow injection (FI) manifold. FI spectrophotometric determinations were made by the blue indophenol reaction for ammonium, the molybdenum blue method for phosphate, the cresolphthalein complexone procedure for calcium, and the mercuric thiocyanate procedure for chloride. The chromogenic reagents for copper, iron, manganese, and zinc determination were bis(cyclohexanone)oxalydihydrazone (Cuprizone), 1,10-phenanthroline, formaldoxime, and xylenol orange, respectively. Sample digestion catalyst, Fl manifold, and some chemical parameters were optimized. The proposed procedure had a sampling rate of 90/h for each analyte. The determination ranges (mg/L) were 10^-60 for N, 1-15 for P and Ca, 5-40 for Cl, and 0.5-15 for Cu, Fe, Mn, and Zn, respectively. Results of the analyzes of animal feed and feedstuff samples by this procedure did not differ significantly from those obtained by proven manual methods.

"Determination Of Manganese In Feedstuffs By Flow Injection Spectrophotometry Based On Rapid Formation Of Permanganate At Room Temperature"
J. AOAC Int. 2001 Volume 84, Issue 4 Pages 1011-1015
Jing-Fu Liu, Ying-Di Feng and Gui-Bin Jiang

Abstract: A simple and rapid flow injection spectrophotometric procedure was developed for determination of manganese. In the presence of pyrophosphate and acetate, manganese was immediately oxidized to permanganate by periodate at room temperature in slightly alkaline medium. Under optimized conditions, the determination was made with a sampling rate of 120/h, a linear range of 0-30 mg/L Mn(II), a detection limit (S/N = 3) of 0.08 mg/L, and a relative standard deviation of 0.6% (n = 11) at 10 mg/L Mn(II). The proposed method was used to determine manganese in trace mineral premixes and feedstuffs. Results agreed well with those obtained by the standard atomic absorption spectroscopy method. [Journal Article; In English; United States]

"Flow Injection Spectrophotometric Determination Of Copper, Iron, Manganese, And Zinc In Animal Feeds Using A Common Manifold"
J. AOAC Int. 2000 Volume 83, Issue 6 Pages 1293-1298
Jing-Fu Liu, Gui-Bin Jiang, and Ying-Di Feng

Abstract: A rapid and simple procedure was developed for the determination of copper, iron, manganese, and zinc in animal feeds using an identical flow injection spectrophotometric manifold but different chromogenic reagents and different detection wavelengths, Bis(cyclohexanone)oxalydihydrazone, formaldoxime, 1,10-phenanthroline, and xylenol orange were adopted as chromogenic reagents for Cu, Min, Fe, and Zn, respectively. Detection conditions such as manifold parameters, buffer pH, reagent concentration, temperature, and acidity of sample solution were optimized. Analytical characteristics of the method and interference of metal ions commonly present in feeds were studied. By changing the reagents and detection wavelengths, which can be done quickly, the proposed low cost flow injection system can determine Cu, Fe, Mn, or Zn in the range of 0.5-10 mg/L with a sampling throughput of 120/h.
Preconcentration

"Trace Analysis Of Sulfonylurea Herbicides In Water By On-line Continuous Flow Liquid Membrane Extraction-C18 Precolumn Liquid Chromatography With Ultraviolet Absorbance Detection"
J. Chromatogr. A 2003 Volume 995, Issue 1-2 Pages 21-28
Jing-fu Liu, Jing-bo Chao, Gui-bin Jiang, Ya-qi Cai and Jie-min Liu

Abstract: An on-line system that consists of continuous-flow liquid membrane extraction (CFLME), C18 precolumn, and liquid chromatography with UV detection was applied to trace analysis of sulfonylurea herbicides in water. During pre-concentration by CFLME, five target compounds, including metsulfuron methyl, bensulfuron methyl, tribenuron methyl, sulfometuron methyl, and ethametsulfuron, were enriched in 960 µl of 0.5 mol L-1 Na2CO3-NaHCO3 (pH 10.8) buffer used as acceptor. This acceptor was on-line neutralized and transported to the C18 precolumn where the analytes were absorbed and focused. Then the focused analytes were injected onto a C18 analytical column for separation and detection at 240 nm. The proposed method was applied to determine sulfonylurea herbicides in water, river, and reservoir water with detection limits of 10^-50 ng L-1 when enriching a 120 mL sample. Throughput is typically one sample per hour.

"Determination Of Sulfonylurea Herbicides By Continuous-flow Liquid Membrane Extraction On-line Coupled With High-performance Liquid Chromatography"
J. Chromatogr. A 2002 Volume 955, Issue 2 Pages 183-189
Jing-bo Chao, Jing-fu Liu, Mei-juan Wen, Jie-min Liu, Ya-qi Cai and Gui-bin Jiang

Abstract: On-line coupling continuous-flow liquid membrane extraction (CFLME) with HPLC, a novel automatic system was developed for the determination of sulfonylurea herbicides in water. After an automatic trace-enrichment process by CFLME, which is the combination of continuous flow liquid-liquid extraction and support liquid membrane (SLM) extraction, the target analytes were concentrated in 50 µl of 0.2 M Na2CO3-NaHCO3 (pH 10.0) buffer. The concentrated sample solutions were injected directly onto a C18 analytical column with a valve, and detected at 240 nm with a diode array detector. Metsulfuron methyl (MSM), and DPX-A 7881 were baseline separated with a mobile phase consisting of methanol and 67 mM KH2PO4-Na2HPO4 (pH 5.91) buffer (45+55, v+v) at a flow-rate of 1.0 mL min-1. With an enrichment time of 10 min and enrichment sample volume of 20 ml, the enrichment factors and detection limits are 100 and 0.05 µg L-1 for MSM, and 96 and 0.1 µg L-1 for DPX-A 7881, respectively. The linear range and precision (RSD) are 0.1-50 µg L-1 and 7.0% for MSM, and 0.2-50 µg L-1 and 9.2% for DPX-A 7881, respectively. This proposed method was applied to determine MSM and DPX-A 7881 in seawater, tap water, and bottled mineral water with spiked recoveries in the range of 83-95% for MSM and 88-100% for DPX-A 7881, respectively.

"Arsenic Speciation Based On Ion Exchange High-performance Liquid Chromatography Hyphenated With Hydride Generation Atomic Fluorescence And On-line UV Photo Oxidation"
Fresenius J. Anal. Chem. 2000 Volume 368, Issue 8 Pages 803-808
He Bin, Jiang Gui-bin, Xu Xiao-bai

Abstract: An on-line method capable of the separation of arsenic species was developed for the speciation of arsenite As(III), arsenate As(V), monomethylarsenic (MMA) and dimethylarsenic acid (DMA) in biological samples. The method is based on the combination of high-performance liquid chromatograph (HPLC) for separation, UV photo oxidation for sample digestion and hydride generation atomic fluorescence spectrometry (HGAFS) for sensitive detection. The best separation results were, obtained with an anion-exchange AS11 column protected by an AG11 guard column, and gradient elution with NaH2PO4 and water as mobile phase. The on-line UV photo oxidation with 1.5% K2S2O8 in 0.2 mol L-1 NaOH in an 8 m PTFE coil for 40 s ensures the digestion of organoarsenic compounds. Detection limits for the four species were in the range of 0.11-0.15 ng (20 µL injected). Procedures were validated by analysis of the certified reference materials GBW09103 freeze-dried human urine and the results were in good agreement with the certified values of total arsenic concentration. The method has been successfully applied to speciation studies of blood arsenic species with no need of sample pretreatment. Speciation of arsenic in blood samples collected from two patients after the ingestion of realgar-containing drug reveals slight increase of arsenite and DMA, resulting from the digestion of realgar.
Optimization

"Tin Compounds And Major Trace Metal Elements In Organotin-poisoned Patients Urine And Blood Measured By Gas Chromatography-flame Photometric Detector And Inductively Coupled Plasma-mass Spectrometry"
Bull. Environ. Contam. Toxicol. 2000 Volume 65, Issue 3 Pages 277-284
Jiang Gui-bin, Zhou Qun-fang, He Bin

Abstract: During 1999 New Year's Days, more than 1000 people in southeast China's Jiangxi province, Longnan and Dingnan county, were poisoned by misusing organotin contaminated industrial lard as cooking oil, among them, hundreds people were hospitalized and three people died from it In this paper, we analyzed urine and blood samples from the patients in this incident The trace levels of inorganic and organotih compounds were determined by a simple and sensitive method which was based on the conversion of tin species into corresponding pentylated compounds and subsequent analyzed by capillary GC-FPD Total tin and 11 major trace metal elements were measured by ICP-MS To our knowledge, this is the first time to found methyltin species in human urine and blood
Derivatization

"Determination Of As Species In Extracts Of The Chinese Medicines Realgar And Orpiment By Ion Chromatography And Hydride Generation GFAAS"
Atom. Spectrosc. 2000 Volume 21, Issue 4 Pages 143-148
He, B.;Jiang, G.B.;Zhang, M.;Xu, X.B.

Abstract: A comprehensive method for the determination of arsenic speciation using ion chromatography (IC) and hydride generation graphite furnace atomic absorption spectrometry (HG-GFAAS) is proposed. Arsenic species including arsenite As(III), arsenate As(V), monomethylarsenate acid (MMA), and dimethylarsenate acid (DMA) were separated on a column system which consisted of an AG11 guard column and an AS11 separation column connected in series with 5 mmol L-1 NaH2PO4 as the mobile phase. Fractions eluted from IC were collected and determined by HG-GFAAS. For a 20 µL injection, the detection limits (3s) were 0.25, 1.76, 0.28, and 9.78 ng mL-1 as As for As(III), As(V), MMA, and DMA, respectively. Bg application of this method, the presence of As(III), As(V), and DMA in various extracts of the Chinese medicines realgar and orpiment were determined.

"Comprehensive-trace Level Determination Of Methyltin Compounds In Aqueous Samples By Cryogenic Purge-and-trap Gas Chromatography With Flame Photometric Detection"
Anal. Sci. 2001 Volume 17, Issue 11 Pages 1279-1283
Jiemin Liu, Guibin Jiang, Qunfang Zhou And Ziwei Yao

Abstract: A comprehensive method was developed for the sensitive and fast determination of trace levels of methyltin compounds in aqueous samples. Tin compounds in aqueous solution at pH 5 were converted to the corresponding volatile hydrides: CH3SnH3, (CH3)(2)SnH2, and (CH3)(3)SnH, by reaction with potassium borohydride. A CP-4010 purge and trap injector (PTI) was used to purge analyte species from water directly. The volatile derivatives were base-line separated on a capillary column in an Angilent-6890 gas chromatograph by a suitable temperature program and were detected by a flame photometric detector (FPD). The detection limits were 18 ng L-1 for monomethyltin, 12 ng L-1 for dimethyltin, and 3 ng L-1 for trimethyltin, respectively. This method was successfully applied to the determination of methyltin compounds in different aqueous samples.

"High Performance Liquid Chromatography Determination Of Chlorophenols In Water Samples After Preconcentration By Continuous Flow Liquid Membrane Extraction On-line Coupled With A Precolumn"
Anal. Chim. Acta 2003 Volume 487, Issue 2 Pages 129-135
Jing-Fu Liu, Xia Liang, Yu-Guang Chi, Gui-Bin Jiang, Ya-Qi Cai, Qing-Xiang Zhou and Guo-Guang Liu

Abstract: A continuous flow liquid membrane extraction (CFLME)-C18 precolumn-liquid chromatography system was developed for pre-concentration and determination of chlorinated phenols (CPs). After pre-concentration by CFLME, which is based on the combination of continuous flow liquid-liquid extraction and supported liquid membrane, CPs were enriched in 960 µL of 0.5 mol L-1 NaOH used as acceptor. This acceptor was on-line neutralized and transported onto the C18 precolumn where analytes were absorbed and focused. Then the focused analytes were injected onto the C18 analytical column for separation and detected at 215 nm with a diode array detector. CFLME related parameters such as flow rates, pH of donor and acceptor concentration were optimized. The proposed method presents detection limits of 0.02-0.09 µg L-1 (S/N=3) when 100 mL samples were enriched. The proposed method was successfully applied to determine CPs in tap water and river water samples with spiked recoveries in the range of 70-121%.

"Determination Of As(III) And As(V) In Soils Using Sequential Extraction Combined With Flow Injection Hydride Generation Atomic Fluorescence Detection"
Anal. Chim. Acta 2003 Volume 477, Issue 1 Pages 139-147
Jian-bo Shi, Zhi-yong Tang, Ze-xiang Jin, Quan Chi, Bin He and Gui-bin Jiang

Abstract: An analytical procedure for determination of As(III) and As(V) in soils using sequential extraction combined with flow injection (FI) hydride generation atomic fluorescence spectrometry (HG-AFS) was presented. The soils were sequentially extracted by water, 0.6 mol L-1 KH2PO4 solution, 1% (v/v) HCl solution and 1% (w/v) NaOH solution. The arsenite (As(III)) in extract was analyzed by HG-AFS in the medium of 0.1 mol L-1 citric acid solution, then the total arsenic in extract was determined by HG-AFS using on-line reduction of arsenate with -cysteine. The concentration of arsenate (As(V)) was calculated by the difference. The optimum conditions of extraction and determination were studied in detail. The detection limit (3s) for As(III) and As(V) were 0.11 and 0.07 µg l-1, respectively. The relative standard deviation (RSD) was 1.43% (n=11) at the 10 µg L-1 As level. The method was applied in the determination of As(III) and As(V) of real soils and the recoveries of As(III) and As(V) were in the range of 89.3-118 and 80.4-111%, respectively.

"Speciation Analysis Of Mercury In Seafood By Using High-performance Liquid Chromatography On-line Coupled With Cold-vapor Atomic Fluorescence Spectrometry Via A Post Column Microwave Digestion"
Anal. Chim. Acta 2003 Volume 477, Issue 1 Pages 131-137
Li-Na Liang, Gui-Bin Jiang, Jing-Fu Liu and Jing-Tian Hu

Abstract: An automatic system, based on the on-line coupling of high-performance liquid chromatography (HPLC) separation, post column microwave digestion, and cold-vapor atomic fluorescence spectrometry (CVAFS) detection, was proposed for the speciation analysis of four mercury compounds. Post column microwave digestion, in the presence of potassium persulfate (in HCl), was applied in the system to improve the conversion efficiency of three organic mercury compounds into inorganic mercury. Parameters influencing the on-line digestion efficiency and the separation effect were optimized. To avoid water vapor and methanol entering into the atomic fluorescence detector, ice-water mixture bath was used to cool the microwave-digested sample solution. Four mercury species including inorganic mercury chloride (MC), methylmercury chloride (MMC), ethylmercury chloride (EMC) and phenylmercury chloride (PMC) were baseline separated within 13 min by using RP C18 column with a mobile phase of 50% (v/v) methanol containing 10 mmol L-1 tetrabutyl ammonium bromide and 0.1 mol L-1 sodium chloride pumped at 1.2 mL min-1. Seafood samples, composed of three gastropod species and two bivalve species from Yantai port, China, have been analyzed by the proposed method. Dogfish muscle (DORM-2) was analyzed to verify the accuracy of the method and the result was in good agreement with the certified value.

"Continuous Flow Liquid Membrane Extraction: A Novel Automatic Trace-enrichment Technique Based On Continuous Flow Liquid-liquid Extraction Combined With Supported Liquid Membrane"
Anal. Chim. Acta 2002 Volume 455, Issue 1 Pages 93-101
Jing-Fu Liu, Jing-Bo Chao and Gui-Bin Jiang

Abstract: Combining the continuous flow liquid-liquid extraction (CFLLE) and supported liquid membrane (SLM) extraction, a novel aqueous-aqueous extraction technique that we termed continuous flow liquid membrane extraction (CFLME) is developed for trace-enrichment. The analyte was firstly extracted into the organic phase in the CFLLE step, then transported onto the organic liquid membrane that formed on the surface of the µporous membrane of the SLM equipment. Finally, it passed through the liquid membrane and was trapped by the acceptor. Aspects related to CFLME were studied by using dichloromethane as liquid membrane, and sulfonylurea herbicides as model compounds. An enrichment factor of over 1000 was obtained when 10 µg L-1 of MSM was enriched for 120 min by this technique. The drawbacks of only a few organic solvents can be selected as liquid membrane with a limited lifetime in SLM operation was overcome. In this CFLME method, almost all solvents that used in the conventional liquid-liquid extraction (LLE) can be adopted and the lifetime of liquid membrane is no longer a problem.