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Sun H.,Hebei University | Ge X.,Hebei University | Lv Y.,Hebei University | Wang A.,Beijing Titan Instruments Co.
Journal of Chromatography A | Year: 2012

Accelerated solvent extraction (ASE) has become a popular green extraction technology for different classes of organic contaminants present in numerous kinds of food and feed for food safety. The parameters affecting ASE efficiency and application advancement of ASE in the analysis of organic contaminants, natural toxins compounds as well as bioactive and nutritional compounds in animal origin food, plant origin food and animal feed are reviewed in detail. ASE is a fully automated and reliable extraction technique with many advantages over traditional extraction techniques, so it could be especially useful for routine analyses of pollutants in food and feed. © 2012 Elsevier B.V..


de Jesus A.,Federal University of Rio Grande do Sul | Sturgeon R.E.,National Research Council Canada | Liu J.,Beijing Titan Instruments Co. | Silva M.M.,Federal University of Rio Grande do Sul | Silva M.M.,Brazilian National Council for Scientific and Technological Development
Microchemical Journal | Year: 2014

Quantitation of mercury in gasoline by graphite furnace atomic absorption spectrometry following its photochemical vapor generation is described. Samples were prepared as a mixture of gasoline and propan-2-ol. A high efficiency flow through 19W photochemical vapor generator was used to process prepared samples with in-situ collection of the resultant Hg0 vapor onto reduced palladium in the graphite tube. Response from inorganic and organomercury standards added to the samples did not differ significantly. A limit of detection and characteristic mass of 0.1μgL-1 and 0.6ng were obtained, respectively. Relative standard deviations of replicate measurements of 3.0ngmL-1 added Hg(II) were typically 7-8%. Recoveries of spikes from samples ranged from 90 to 97%. The concentration of mercury in all tested samples of gasoline was below the limit of quantitation (0.3μgL-1). The method was rapid, efficient, green, fit-for-purpose, responsive to both inorganic and organic mercury species and should also respond to any Hg0 endogenously present in the sample. © 2014 Elsevier B.V.


Mao X.,Chinese Academy of Agricultural Sciences | Qi Y.,Chinese Academy of Agricultural Sciences | Huang J.,Beijing Titan Instruments Company | Liu J.,Chinese Academy of Agricultural Sciences | And 5 more authors.
Analytical Chemistry | Year: 2016

A novel dielectric barrier discharge reactor (DBDR) was utilized to trap/release arsenic coupled to hydride generation atomic fluorescence spectrometry (HG-AFS). On the DBD principle, the precise and accurate control of trap/release procedures was fulfilled at ambient temperature, and an analytical method was established for ultratrace arsenic in real samples. Moreover, the effects of voltage, oxygen, hydrogen, and water vapor on trapping and releasing arsenic by DBDR were investigated. For trapping, arsenic could be completely trapped in DBDR at 40 mL/min of O2 input mixed with 600 mL/min Ar carrier gas and 9.2 kV discharge potential; prior to release, the Ar carrier gas input should be changed from the upstream gas liquid separator (GLS) to the downstream GLS and kept for 180 s to eliminate possible water vapor interference; for arsenic release, O2 was replaced by 200 mL/min H2 and discharge potential was adjusted to 9.5 kV. Under optimized conditions, arsenic could be detected as low as 1.0 ng/L with an 8-fold enrichment factor; the linearity of calibration reached R2 > 0.995 in the 0.05 μg/L-5 μg/L range. The mean spiked recoveries for tap, river, lake, and seawater samples were 98% to 103%; and the measured values of the CRMs including GSB-Z50004-200431, GBW08605, and GBW(E)080390 were in good agreement with the certified values. These findings proved the feasibility of DBDR as an arsenic preconcentration tool for atomic spectrometric instrumentation and arsenic recycling in industrial waste gas discharge. (Figure Presented). © 2016 American Chemical Society.


PubMed | Beijing Titan Instruments Company, Chinese Academy of Agricultural Sciences and U.S. Department of Agriculture
Type: Journal Article | Journal: Analytical chemistry | Year: 2016

A novel dielectric barrier discharge reactor (DBDR) was utilized to trap/release arsenic coupled to hydride generation atomic fluorescence spectrometry (HG-AFS). On the DBD principle, the precise and accurate control of trap/release procedures was fulfilled at ambient temperature, and an analytical method was established for ultratrace arsenic in real samples. Moreover, the effects of voltage, oxygen, hydrogen, and water vapor on trapping and releasing arsenic by DBDR were investigated. For trapping, arsenic could be completely trapped in DBDR at 40 mL/min of O2 input mixed with 600 mL/min Ar carrier gas and 9.2 kV discharge potential; prior to release, the Ar carrier gas input should be changed from the upstream gas liquid separator (GLS) to the downstream GLS and kept for 180 s to eliminate possible water vapor interference; for arsenic release, O2 was replaced by 200 mL/min H2 and discharge potential was adjusted to 9.5 kV. Under optimized conditions, arsenic could be detected as low as 1.0 ng/L with an 8-fold enrichment factor; the linearity of calibration reached R(2) > 0.995 in the 0.05 g/L-5 g/L range. The mean spiked recoveries for tap, river, lake, and seawater samples were 98% to 103%; and the measured values of the CRMs including GSB-Z50004-200431, GBW08605, and GBW(E)080390 were in good agreement with the certified values. These findings proved the feasibility of DBDR as an arsenic preconcentration tool for atomic spectrometric instrumentation and arsenic recycling in industrial waste gas discharge.


Qin D.,Beijing Titan Instruments Co. | Gao F.,Beijing Entry Exit Inspection and Quarantine Bureau | Zhang Z.,Beijing Entry Exit Inspection and Quarantine Bureau | Zhao L.,Beijing Titan Instruments Co. | And 4 more authors.
Spectrochimica Acta - Part B Atomic Spectroscopy | Year: 2013

A novel method, which coupled an on-line solid phase extraction (SPE) enrichment with ultraviolet vapor generation (UVG) atomic fluorescence spectrometry (AFS), was developed to improve the sensitivity of mercury determination and to remove the interference of some anion and organics to UVG of mercury. A high mercury retention efficiency and maximum exclusion of inorganic and organic matrix in water samples were achieved by using C 18 SPE mini cartridge modified with sodium diethyldithiocarbamate (DDTC). Fast and efficient elution from the cartridge was found by using l-cysteine mixing solution. Furthermore, through the investigation of different UV reactor designs, the most important factor was the structure of the reactor (which corresponded roughly to the photon flux) wherein the tubing was sintered into the UV lamp to give the highest UV generation efficiency. The second factor was the materials of the tubing (which roughly corresponded to the working wavelength). Synthetic quartz, characterized by the highest transparency at 185 nm, attained the highest UVG efficiency, suggesting that the most favorable wavelength for UVG was 185 nm. Under optimum conditions, the achievable detection limit (3σ) with sample loadings of 10.0 mL was 0.03 ng L - 1 and 0.08 ng L- 1 with different manifolds, respectively. The method was successfully applied to the determination of Hg in tap water, river water and lake water samples. © 2013 Elsevier B.V.


Feng L.,Beijing Titan Instruments Co. | Liu J.,Beijing Titan Instruments Co.
Journal of Analytical Atomic Spectrometry | Year: 2010

A new solid sampling device and procedure for determination of trace cadmium in food samples by atomic fluorescence spectrometry was developed, which made use of a graphite fibre felt (GFF) as the vaporizer and a tungsten-coil (TC) as the cadmium trap. The procedure was optimized by changing temperature and gas atmosphere at vaporizing, trapping and releasing steps respectively. Under optimized conditions, cadmium in solid sample was vaporized with the matrix by GFF at about 1600 °C, then separated from the matrix by trapping on the TC at room temperature; finally, cadmium was released from TC at 2000 °C and directly determined by a non-dispersion atomic fluorescence spectrometer (AFS) without extra atomization. The detection limit (DL) of this procedure was shown to be 30 ng L-1 (0.3 pg); the relative standard deviation (RSD) was less than 5% at 10 μg L-1 (100 pg); and no significant interference was found within a 10% error range. The recoveries for some certified reference materials and the spiked recoveries for some food samples were all satisfied. Furthermore, the mechanism of this procedure was interpreted. © 2010 The Royal Society of Chemistry.


Patent
Beijing Titan Instruments Co. | Date: 2013-10-30

The Ultraviolet pretreatment device in the present invention relates to an interface technique in the field of coupling technology for the analysis of chemical element species. The objective is to provide an Ultraviolet pretreatment device with simple structure, enhanced UV illuminance, and high digestion efficiency. The Ultraviolet pretreatment device in the present invention comprises low pressure Mercury lamp and quartz tube, wherein, the said low pressure Mercury lamp comprises lamp tube, electrodes and power source. The said quartz tube is located within the said lamp tube, the two ends of the quartz tube are fixedly and respectively joined with the tube wall of the lamp tube, the inner wall of the said lamp tube and the outer wall of the quartz tube form a sealed gas chamber, and the said electrodes are located in the gas chamber.


Patent
Beijing Titan Instruments Co. | Date: 2010-12-19

The Ultraviolet pretreatment device in the present invention relates to an interface technique in the field of coupling technology for the analysis of chemical element species. The objective is to provide an Ultraviolet pretreatment device with simple structure, enhanced UV illuminance, and high digestion efficiency. The Ultraviolet pretreatment device in the present invention comprises a low pressure Mercury lamp and a quartz tube, wherein, the low pressure Mercury lamp comprises a lamp tube, electrodes and a power source. The quartz tube is located within the lamp tube, the two ends of the quartz tube are fixedly and respectively joined with the tube wall of the lamp tube, the inner wall of the lamp tube and the outer wall of the quartz tube form a sealed gas chamber, and the electrodes are located in the gas chamber.


An electrothermal vaporization atomic fluorescence spectrometer for determination of Cadmium comprising a sampling system, a light source, an atomizer, a light path system, a detection system, and a display device. The sampling system includes an electrothermal vaporization device and a capture trap; the capture trap comprises a Tungsten or Molybdenum coil (6), a holder (15), a cover (7) and a power supply (17); the cover (7) and the holder (15) form a sealed space; the Tungsten or Molybdenum coil (6) is arranged on the holder (15); the Tungsten or Molybdenum coil (6) is located inside the sealed space formed by the cover (7) and the holder (15); and the cover (7) is provided with an inlet (12) and an outlet (13) thereon. An electrothermal vaporization atomic fluorescence spectroscopy for determination of Cadmium is also provided.


The present invention discloses an electrothermal vaporization atomic fluorescence spectroscopy and spectrometer for determination of Cadmium. The atomizer of the electrothermal vaporization atomic fluorescence spectrometer includes an atomization device and a capture trap; the capture trap comprises a Tungsten or Molybdenum coil, a holder, a cover and a power supply; the cover and the holder form a sealed space; the Tungsten or Molybdenum coil is arranged on the holder; the Tungsten or Molybdenum coil is located inside the sealed space formed by the cover and the holder; the cover is provided with an inlet and an outlet thereon. The electrothermal vaporization atomic fluorescence spectroscopy for determination of Cadmium comprises the following steps: dry the sample to be measured in the air, ash it, and collect the ash; under the Argon gas atmosphere, increase the said ash temperature to 1600~2000 C, and make the resulting steam contact the Tungsten or Molybdenum coil; under the Hydrogen and Argon gas atmosphere, increase the temperature of the said Tungsten or Molybdenum coil to 1600~2000 C release the Cadmium atom, and measure the Cadmium content byanalysis of the atomic fluorescence spectroscopy. The electrothermal vaporization atomic fluorescence spectroscopy and spectrometer for determination of Cadmium in the present invention can efficiently eliminate the matrix interference, and realize the accurate measurement of Cadmium.

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