In situ determination of nitrogen fixation in Antarctica using a high sensitivity portable gas chromatograph

1982 ◽  
Vol 7 (4) ◽  
pp. 395-402 ◽  
Author(s):  
ALLAN DAVEY
Keyword(s):  
Nitrogen Fixation ◽  
High Sensitivity ◽  
Gas Chromatograph ◽  
Portable Gas Chromatograph

scholarly journals Air pollution in landfill of wastes other than hazardous or inert / Zanieczyszczenia powietrza na składowiskach odpadów innych niż niebezpieczne i obojętne

2015 ◽  
Vol 41 (2) ◽  
pp. 41-46 ◽  
Author(s):  
Ewa Miaśkiewicz-Pęska ◽  
Mirosław Szyłak-Szydłowski
Keyword(s):  
Air Pollution ◽  
Chemical Analysis ◽  
Microscopic Fungi ◽  
Gas Chromatograph ◽  
Psychrophilic Bacteria ◽  
Air Samples ◽  
Atmospheric Air ◽  
Bacteria And Fungi ◽  
Portable Gas Chromatograph

Abstract Microbiological and chemical analysis of air was carried out on the area of landfill of wastes other than inert or hazardous. The landfill covers 20 ha and 40 000 Mg of wastes is deposited annually. Municipal waste is not segregated at the landfill. The research was conducted in April, May and November 2012. Number of the psychrophilic and mesophilic bacteria and fungi was estimated by a culture-based method. Quantitative determination of sulfur compounds and meteorological and olfactrometric examinations were also carried out. Chemical analysis was conducted with a Photovac Voyager portable gas chromatograph. Air samples were collected at 5 points. The largest group of microbes were psychrophilic bacteria, especially in summer. The highest concentration of hydrogen sulfide and other odorants was found at leachate tank and landfill body. According to the Polish Standard for the assessment of atmospheric air pollution the air in the area of the landfill is classified as not contaminated and sporadically moderately contaminated. In spring and summer the number of microscopic fungi was increased also in control samples.

A method of high sensitivity and in situ determination of trace cobalt(II) in water samples with salicyl fluorone

2014 ◽  
Vol 70 (7) ◽  
pp. 1182-1187 ◽  
Author(s):  
Zhe Chen ◽  
Hua Li
Keyword(s):  
Flow Injection ◽  
Water Samples ◽  
High Sensitivity ◽  
Basic Solution ◽  
Optimum Conditions ◽  
Cetylpyridinium Bromide ◽  
Test Conditions ◽  
Relative Standard

Based on the sensitive reaction of Co(II) and salicyl fluorone with the presence of cetylpyridinium bromide in basic solution, a new method of flow injection micelle-solubilized spectrophotometry was developed for the determination of cobalt. The reaction was monitored for the absorbance of Co(II) at 540 nm. The reagents, flow injection variables and effects of foreign ions were investigated and the optimum conditions were established. At the optimum test conditions, the developed method provides a linearity range of 3–40 μg L−1 with a detection limit of 0.1 μg L−1 at about 60 h−1 sampling frequency. Relative standard deviation of 0.91, 0.95 and 0.89% were obtained for the determination of 3, 15 and 30 μg L−1 Co(II) solution. The proposed method has been successfully applied for analysis of trace amounts of cobalt in water samples.

Portable Gas Chromatograph with Tunable Retention and Sensor Array Detection for Determination of Complex Vapor Mixtures

2003 ◽  
Vol 75 (6) ◽  
pp. 1400-1409 ◽  
Author(s):  
Chia-Jung Lu ◽  
Joshua Whiting ◽  
Richard D. Sacks ◽  
Edward T. Zellers
Keyword(s):  
Sensor Array ◽  
Gas Chromatograph ◽  
Array Detection ◽  
Vapor Mixtures ◽  
Portable Gas Chromatograph

On-site determination of nerve and mustard gases using a field-portable gas chromatograph-mass spectrometer

2006 ◽  
Vol 24 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Hiroyuki Sekiguchi ◽  
Koji Matsushita ◽  
Shigeharu Yamashiro ◽  
Yasuhiro Sano ◽  
Yasuo Seto ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Gas Chromatograph ◽  
Portable Gas Chromatograph

Combined headspace single-drop microextraction and solid-phase microextraction for the determination of phenols as their methyl ethers by gas chromatography-mass spectrometry

2017 ◽  
Vol 9 (46) ◽  
pp. 6590-6598 ◽  
Author(s):  
Archana Jain ◽  
Soumitra Soni ◽  
Kishan Reddy-Noone ◽  
Aradhana K. K. V. Pillai ◽  
Krishna K. Verma
Keyword(s):  
Solid Phase Microextraction ◽  
Solid Phase ◽  
High Sensitivity ◽  
Large Mass ◽  
Gas Chromatography Mass Spectrometry ◽  
Gas Chromatograph ◽  
Single Drop ◽  
Single Drop Microextraction ◽  
Single Drop Extraction

A combination of headspace large volume single drop extraction and solid phase microextraction permitted attainment of high sensitivity by transferring an overall large mass of analytes into a gas chromatograph.

Determination of Eight Organochlorine Pesticides at Low Nanogram/Liter Concentrations in Groundwater Using Filter Disk Extraction and Gas Chromatography

1992 ◽  
Vol 75 (6) ◽  
pp. 1091-1099 ◽  
Author(s):  
Bruce A Tomkins ◽  
Roosevelt Merriweather ◽  
Roger A Jenkins ◽  
Charles K Bayne
Keyword(s):  
Organochlorine Pesticides ◽  
Environmental Protection Agency ◽  
Anhydrous Sodium Sulfate ◽  
Capillary Column ◽  
High Sensitivity ◽  
Gas Chromatograph ◽  
Method Detection Limit ◽  
Limit Values ◽  
Groundwater Samples

Abstract Eight organochlorine pesticides may be quantitated routinely at levels below 10 parts per trillion (ng/L) in natural groundwaters. Analytes are extracted rapidly from 1 L groundwater samples by using conditioned Teflon filter disks impregnated with silica containing bonded octadecyl phase. Filter is dried briefly under vacuum, and pesticides are eluted with 10 mL ethyl acetate. The extract is dried with about 1 g anhydrous sodium sulfate and then concentrated to exactly 1 mL. Pesticides are separated in a gas chromatograph equipped with a capillary column, detected by a high-sensitivity electron capture detector, and quantitated by the method of external standards. Certified reporting limit (CRL) values for the 8 pesticides ranged between 2 and 7 ng/L. Preliminary data demonstrated that the organochlorine pesticides could be collected on the filter disks and stored up to 4 weeks in the dark at either refrigerated or ambient temperature without obvious degradation of the sample. Calculated CRL values are comparable (within a factor of 2) to method detection limit values defined by the U.S. Environmental Protection Agency.

scholarly journals A home – made purge and trap – thermos desorption - gas chromatograph coupled with atomic fluorescence detector for the determination of ultra – trace methylmercury

2019 ◽  
Vol 2 (3) ◽  
pp. 94-101
Author(s):  
Mai Thi Huynh Le ◽  
Hau Cong Nguyen ◽  
Thanh Quan Huynh ◽  
Dong Van Nguyen
Keyword(s):  
Aqueous Sample ◽  
Gas Chromatograph ◽  
Fluorescence Detector ◽  
Atomic Fluorescence ◽  
Separation Device ◽  
Purge And Trap ◽  
Quality Control Chart ◽  
Ultra Trace

A hyphenated system for methylmercury based on a gas chromatograph (GC) coupled with an atomic fluorescence spectrometric (AFS) detector equipped with an online purge and trap as a preconcentrator was made. Operating parameters for the whole system were optimized and analytical performances of the system are verified by quality control chart for stability. Organomercurial compounds in an aqueous sample were in-situ ethylated and purged to a trap in-line with a separation device instead of conventional off-line solvent extraction. A 100 mL aqueous sample containing methylmercury in an impinger was mixed with sodium tetraethylborate at pH 5.0. The forming volatile ethylmethylmercury was purged for 30 minutes with the assistance of an Ar flow and trapped into a Tenax sorbent. The trap was then heated to release volatile compounds including ethylmethylmercury into a GC-AFS for separation and detection. The instrumental detection limit was 4.8 pg Hg/L. The method can therefore be applied for the determination of methylmercury in water samples at ultra – trace.

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