Trichloroacetic detection limit

The phenols pyrocatechol, resorcinol and hydroquinone can be detected with all chloramine T reagents. The detection sensitivity is about the same with chloramine T - sodium hydroxide and chloramine T - trichloroacetic acid. In all cases the detection limits are ca. 75 ng substance per chromatogram zone after the plate has been subsequently dipped in a paraffin oil solution. Somewhat less favorable detection limits of 150 to 200 ng substance per chromatogram zone are obtained after treatment with chloramine T - hydrochloric acid and chloramine T - sulfuric acid. 

Gas Chromatography. In plasma or urine trichloroethanol, ECD—D. J. Berry, Chromat., 1975,107, 107-114. In blood or urine chloral hydrate, trichloroethanol and trichloroacetic acid, head-space analysis, detection limit 500 ng/ml for chloral hydrate and trichloroethanol, ECD—D. D. Breimer et al., J. Chromat., 1974,88, 55-63. 

Quantification. Gas Chromatography. In blood using head-space analysis, FID—F. N. Prior, Anaesthesia, 1972, 27, 379-389. In blo or urine trichloroethanol and trichloroacetic acid, using headspace analysis, detection limit 500 ng/ml for trichlo-... 

Serum copper analysis was performed using a Perkin-Elmer atomic absorption spectrophotometer. Model 308. The previously described method by Prasad (136) was used after slight modification. For protein precipitation we used 7.5% trichloroacetic acid instead of 2N HCl used by Prasad. Analytical sensitivity for copper with this method was 0.2 jxg/ mL for 1% absorption and a relative detection limit of 0.005 fig/mL, Recovery studies done by adding known amounts of copper to the serum ranged between 96-104%. Analysis for ceruloplasmin was made by using commercially available immunodiffusion plates (Hyland, Inc. normal range, 20-35 mg/100 mL). Precision of the method has been tested by running 20 determinations for both copper and ceruloplasmin on one aliquot. CoeflBcient of variation did not vary by more than 3-5%. All samples were run in duplicates. 

An axenic poplar cell culture experiment exhibited conclusively that poplar cells are capable of transforming and mineralizing TCE without the involvement of microbial metabolism. The metabolites of TCE in cell cultures include trichloroethanol, trichloroacetic acid, and dichloroacetic acid, which was the most predominant. Chloral hydrate was also found at levels lower than the detection limit and is a product of TCE oxidation by cytochrome P-450 oxygenase and the precursor of trichloroethanol and trichloroacetic acid in mammalian systems. The same metabolites were identified in field sites where vegetation was exposed to TCE contaminated groundwater and in laboratory studies. ... 

Berman (1967) complexed mercury with ammonium pyrrolidine dithiocarbamate (APDC) in urine, blood, and other tissue samples treated with trichloroacetic acid. She extracted the complex into methylisobutyl ketone (MIBK), and reported a detection limit of about 10 /complexed with APDC, can be quantitively extracted into MIBK from hydrochloric acid (at least up to 6 M) and nitric acid (up to 1.5 M) solutions (Brooks et al., 1989). 

Several methods are available for the analysis of tetrachloroethylene in biological media. The method of choice depends on the nature of the sample matrix required precision, accuracy, and detection limit cost of analysis and turnaround time of the method. Since tetrachloroethylene is metabolized in the human body to trichloroacetic acid (TCA), TCA may be quantified in blood and urine as an indirect measure of tetrachloroethylene exposure (Monster et al. 1983). It should be pointed out that the determination of TCA may not provide unambiguous proof of tetrachloroethylene exposure since it is also a metabolite of trichloroethylene. Trichloroethanol has also been thought to be a metabolite of tetrachloroethylene, identified following occupational exposure (Bimer et al. 1996 Ikeda et al. 1972 Monster et al. 1983). However, rather than being a metabolite of tetrachloroethylene, it is more likely that trichloroethanol is formed from trichloroethylene, which is often found as a contaminant of tetrachloroethylene (Skender et al. 1991). Methods for the determination of trichloroethylene and trichloroethanol are summarized in the Toxicological Profile for Trichloroethylene (ATSDR 1993). 

Nitric acid, trichloroacetic acid, dichloroacetic acid, chloral, and acetic acid in water were resolved on a Cjg column (2 = 210nm) using an aqueous 150mM ammonium sulfate mobile phase [1555]. Peak shapes were excellent except for chloral, which was badly tailed. The tailing may be indicative of the instability of this compound. Detection limits of 10 pg/L (S/N = 4) were reported. Elution was complete in 16 min. 

A similar approach was used to deposit myoglobin on mesoporous Ti02/ AuNP. The wave found at -0.34 V versus Ag/AgCl (3.0 M KCl) shifted linearly as a function of pH with a slope of -51.3 mV/pH, as expected for a reversible electrochemical process coupled with a proton transfer reaction. This biosensor was sensitive to trichloroacetic acid exhibiting a linear response in the 2.0-12 pM range and the detection limit was estimated as been 0.12 pM [173]. 

Bergstrom et al. [63] used HPLC for determination of penicillamine in body fluids. Proteins were precipitated from plasma and hemolyzed blood with trichloroacetic acid and metaphosphoric acid, respectively, and, after centrifugation, the supernatant solution was injected into the HPLC system via a 20-pL loop valve. Urine samples were directly injected after dilution with 0.4 M citric acid. Two columns (5 cm x 0.41 cm and 30 cm x 0.41 cm) packed with Zipax SCX (30 pm) were used as the guard and analytical columns, respectively. The mobile phase (2.5 mL/min) was deoxygenated 0.03 M citric acid-0.01 M Na2HP04 buffer, and use was made of an electrochemical detector equipped with a three-electrode thin-layer cell. The method was selective and sensitive for mercapto-compounds. Recoveries of penicillamine averaged 101% from plasma and 107% from urine, with coefficients of variation equal to 3.68 and 4.25%, respectively. The limits of detection for penicillamine were 0.5 pm and 3 pm in plasma and in urine, respectively. This method is selective and sensitive for sulfhydryl compounds. 

Shaw et al. [64] described a (D)-penicillamine detection method in blood samples that had been treated with EDTA, deproteinized with trichloroacetic acid, and analyzed within 1 h. Penicillamine was detected at a vitreous-carbon electrode operated at +800 mV after HPLC separation. A linear calibration graph was obtained, and the method had a limit of detection equal to 5-20 ng. The method was useful in clinical and in pharmacokinetic studies. 

PDMS = polydimethylsiloxane. PA = polyacrylate. CW = Carbowax. DVB = divinylbenzene. FID = flame ionization detection. NPD = nitrogen-phosphorus detection. TSD = thermionic-specific detection. LOQ = limit of quantitation. LOD = limit of detection. TCA = trichloroacetic acid. PICI-MS = positive ion chemical mass spectrometry. SIM = selected ion monitoring. 

The Frank and Demint [200] method is directly applicable to water samples. After addition of sodium chloride (340g IT1) and aqueous hydrochloric acid (1 1) to bring the pH to 1, the sample was extracted with ethyl ether and the organic layer was then extracted with 0.1M sodium bicarbonate (saturated with sodium chloride and adjusted with sodium hydroxide to pH8). The aqueous solution adjusted to pHl with hydrochloric acid was extracted with ether and after evaporation of the ether to a small volume, Dalapon was esterified at room temperature by addition of diazomethane (0.5% solution in ether) and then applied to a stainless steel column (1.5m/3mm) packed with Chromosorb P (60-80 mesh) pretreated with hexamethyldisilazane and then coated with 10% FFAP. The column was operated at 140°C, with nitrogen carrier gas (30mL muT1) and electron capture detection. The recovery of Dalapon ranged from 91 to 100% the limit of detection was O.lng. Herbicides of the phenoxyacetic acid type did not interfere trichloroacetic acid could be determined simultaneously with Dalapon. 

LOD, limit of detection NR, not reported MDC. mircodiffusion cell TCA, trichloroacetic acid AAS. atomic absorption spectrometry UV, ultraviolet absorbance detection ECD, electron capture detection NPD, nitrogen phosphorus detection GC-MSD, gas chromatography-mass selective detection GC, gas chromatography ATC, 2-amino-1hiazoline-4-carboxylic acid. 

For their detection, the papers may be sprayed with reagents commonly used for the detection of keto and aminodeoxy sugars. Those of particular value include the direct Ehrlich reaction, the orcinol-trichloroacetic acid reagent, the chlorine-benzidine reagent for the detection of —NH—CO— groupings, and the Bial reaction as modified by Bohm und Baumeister. The limit of detection with the orcinol-trichloroacetic acid reagent is reported to be 5 ixg. of V-acetylneuraminic acid. For the detection of methoxyneuraminic acid, ninhydrin may also be used. 

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