Chromatography liquid with electron capture

Very few biological materials have been analyzed for the presence of MBOCA or its metabolites. MBOCA and its metabolites have been measured in urine of exposed humans and experimental animals. Hemoglobin adducts have also been measured in the blood of exposed animals. The most frequently used techniques are gas chromatography (GC) with electron capture detection (ECD) and high-performance liquid chromatography (HPLC) with electrochemical detection (ED). Detailed methodologies from selected studies are presented in Table 6-1. 

Since NIV occurs as a co-contaminant with other trichothecene mycotoxins, it is often analyzed simultaneously with the co-contaminants rather than alone. Analytical methods developed so far include thin layer chromatography (TLC) capillary gas chromatography (GC) with electron-capture detection (BCD), flame ionization detection (FID), or mass spectrometric detection (GC/MS) high-performance liquid chromatography (HPLC) with ultraviolet (UV), fluorescence, or mass spectrometric detection supercritical fluid chromatography (SFC) and time-of-flight mass spectrometry (LC/TOF-MS). 

A sensitive method was described for the detection and estimation of residues of niclosamide in bananas involving extraction of niclosamide, purification of the extract by solvent partition and column chromatography, formation of the hepta-fluorobutyryl derivative of 2-chloro-4-nitroaniline in 99% yield, and determination of the derivative by gas liquid chromatography with electron capture detection. 

Shimoishi [ 555 ] determined selenium by gas chromatography with electron capture detection. To 50-100 ml seawater was added 5 ml concentrated hydrochloric acid and 2 ml 4-nitro-o-phenylenediamine (1%) and, after 2 hours, the product formed was extracted into 1 ml of toluene. The extract was washed with 2 ml of 7.5 M hydrochloric acid, then a sample (5 pi) was injected into a glass gas-liquid chromatography column (lm x 4 mm) packed with 15% of SE-30 on Chromosorb W (60-80 mesh) and operated at 200 °C with nitrogen (53 ml/min) as carrier gas. There is no interference from other substances present in seawater. The detection limit is 5 ng/1 with 200 ml samples, and the precision at a Se level of 0.025 pg/1 is 6%. 

Techniques for analysis of different mercury species in biological samples and abiotic materials include atomic absorption, cold vapor atomic fluorescence spectrometry, gas-liquid chromatography with electron capture detection, and inductively coupled plasma mass spectrometry (Lansens etal. 1991 Schintu etal. 1992 Porcella etal. 1995). Methylmercury concentrations in marine biological tissues are detected at concentrations as low as 10 pg Hg/kg tissue using graphite furnace sample preparation techniques and atomic absorption spectrometry (Schintu et al. 1992). 

Spectrophotometric determination with 4-hexylresorcinol and a fluorometric method with m-aminophenol are the most commonly used procedures for the determination of acrolein. However, gas chromatography and high-performance liquid chromatography procedures are also used (USEPA 1980 Kissel etal. 1981 Nishikawa and Hayakawa 1986). Acrolein concentrations in rainwater between 4 and 200 pg/L can be measured rapidly (less than 80 min) without interference from related compounds the method involves acrolein bromination and analysis by gas chromatography with electron capture detection (Nishikawa and Hayakawa 1986). Kissel etal. (1981) emphasize that water samples from potential acrolein treatment systems require the use of water from that system in preparing blanks, controls, and standards and that acrolein measurements should be made at the anticipated use concentrations. 

Petrick G, Schulz DE, Duinker JC. 1988. Clean-up of environmental samples by high-performance liquid chromatography for analysis of organochlorine compounds by gas chromatography with electron- capture detection. J Chromatogr 435(1 ) 241 -248. 

Infrared spectra were recorded on a Perkin Elmer Model 567 Spectrophotometer. Ultraviolet spectra were obtained on a Cary 1756 Spectrophotometer. Gas chromatograms were recorded on a Tracor Model 220 with electron capture detector. High pressure liquid chromatography studies were conducted with a Waters Model ALC-200 with ultraviolet and refractive index detectors. 

It is difficult to compare recoveries obtained by different laboratories because their extraction conditions (pH, phase ratio, number and time-length of extractions, salinity) are generally different. Sample volumes can be very high, up to 200 1 [433], and 50 1 of surface water [434] or 201 of sea water allow the extraction of 5 ng/1 of alkanes. When using a specific detection method, the sample volume can be lower 2 ng/1 of PAH was determined from 11 of river water using liquid chromatography and fluorescence detection [435]. Chlorophenols below the 10 ng/1 level were determined from 100 ml of sea water with electron capture detection (ECD) GC [436]. 

Munch DJ, Munch JW, Pawlecki AM (1995) EPA Method 552.2. Determination of haloacetic acids and dalapon in drinking water by liquid-liquid extraction, derivatization and gas chromatography with electron capture detection. U.S. EPA, Cincinnati, OH, Available at http //www.caslab.com/EPA-Methods/PDF/552 2.pdf... 

For the detection, gas chromatography (GC) [15,18-20, 28] and liquid chromatography (LC) [14—16, 21, 22, 24, 26-29] coupled with mass spectrometry (MS) or tandem mass spectrometry (MS/MS) have been the techniques most frequently used in the determination of pesticides in ground water. Examples of the application of both techniques in the area of study, Catalonia, are the work of Garrido et al. [17], who used GC-MS and GC with electron capture detection (ECD) for the analysis of 44 pesticides in groundwater samples from Catalonia and that of Kampioti et al. [25], who used online SPE-LC-MS/MS to analyse 20 pesticides in river water and... 

The inherent insensitivity of these methods prompted an evaluation of gas-liquid chromatography with electron capture detection for the analysis of TRIS. Due to the... 

T Mizutani, K Tajima, N Okino, K Yamamoto. Derivatization of butylated hydroxytoluene for gas chromatography with electron-capture detection and high-performance liquid chromatography with ultraviolet detection. J Chromatogr 333 171-174, 1985. 

JJ Jimenez, JL Bernal, MJ del Nozal, JM Rivera. Determination of pesticide residues in waters from small loughs by solid-phase extraction and combined use of gas chromatography with electron-capture and nitrogen-phosphorus detection and high-performance liquid chromatography with diode array detection. J Chromatogr A 289-300, 1997. 

A. Sedman and J. Gal, Simultaneous determination of the enantiomers of tocainide in blood plasma using gas liquid chromatography with electron capture detection, J. Chromatogr., 506 155-164 (1984). 

Beryllium has been determined [764] in non saline waters and in sea water at oceanic levels of 2.30pM. Two ml of 0.1M EDTA, 2ml of 1.0M sodium acetate, 1.0ml of benzene and lOOpl of l,l,l-trifluoro-2-4-pentanedione were added sequentially to 150ml samples. Following liquid-liquid extraction using detailed handling procedures, the organic phase was mixed with 1.0ml of 1.0M sodium hydroxide (de-emulsifier), washed several times with distilled water and the resultant beryllium l,l,l-trifluoro-2,4-pentanedione complex analysed by gas chromatography with electron capture detection. 

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