High-pressure liquid chromatography Electrochemical detection

Biochemical analyses of 6-OHDA-injected animals revealed a 93 percent depletion of dopamine. The tissue was assayed using electrochemical detection following separation by high-pressure liquid chromatography (Felice et al. 1978). recorded as ng/mg protein in the nucleus accumbens and compared to control rats with sham lesions (sham=65.5 4.4, lesion=4.9 1.5 t(39)=23.4). A lesion was defined as complete if 75 percent or more of the dopamine was determined to be depleted from the nucleus accumbens compared to mean sham group values. 

MTHF was initially measured by microbiological and radioisotope dilution assay [12, 13], and later by high-pressure liquid chromatography (HPLC) using electrochemical (EC), ultraviolet, or fluorescence detection [14-16]. Compared to other methods, EC detection is more sensitive. 

Electrochemical detection under convective conditions has been applied widely in freshwater measurements. In addition, seawater measurements have been combined with flow injection analysis (FIA) and high pressure liquid chromatography (HPLC) (D.C. Johnson et al., 1986). Well-developed commercial product lines exist, and detection limits are typically in the range of femtomoles. For in situ, shipboard, and land-based measure-... 

J. K. Baker, R. E. Skelton, and C-Y. Ma, Identification of drugs by high pressure liquid chromatography with electrochemical detection, J. Chromatogr., 765 417 (1979). 

The rapidity means that full square-wave voltammograms can be registered in quick succession, chronovoltammograms, an important application being in electrochemical detection of eluents from high-pressure liquid chromatography columns. 

The suprahypothalamic neurotransmitter level can be assessed by a determination of catecholamines in circumscribed brain areas, the technique requires preparation of frozen tissue and isolation of specific nuclei by the micropunch technique. The catecholamines and indolamines can be measured by a radio-enzymatic methods and by a high-pressure liquid chromatography (HPLC) with electrochemical detection. These mechanistic investigations are mostly initiated due to questions arising from the receptor interaction profile of the drug candidate, they may be required to prove that such receptor interactions truly change the functional state of neurotransmitters (functional expression). Mostly, however, the peripheral effects of such neurotransmitter mechanisms (for instance prolactin secretion) are sufficiently distinct. 

High Pressure Liquid Chromatography. In plasma sensitivity 100 ng/ml, electrochemical detection—C. Tovey et al, J. Chromat., 1983, 278 Biomed. AppL, 29, 216-219. 

Quantification. High Pressure Liquid Chromatography. In serum or urine electrochemical detection—L. A. Pachla and P. T. Kissinger, Analyt. Chem., 1976,48, 364-367. In urine UV detection—E. S. Wagner et al., J. Chromat., 1979,163 Biomed. Appl, 5, 225-229. In postmortem tissues UV detection—W. J. Allender, J. analyt. Toxicol., 1982, 6, 202-204. 

Quantification. High Pressure Liquid Chromatography. In equine plasma detection limit lOOpg/ml, electrochemical detection—G. E. Hardee and J. W. Lai, Analyt. Lett. (Part B), 1983,16, 69-75. 

High Pressure Liquid Chromatography. In plasma or serum haloperidol and reduced metabolite, sensitivity 1 ng/ml, electrochemical detection—E. R. Korpi et al., Clin. Chem., 1983, 29, 624-628. 

Quantification. High Pressure Liquid Chromatography. In plasma or urine detection limit 40 pg, fluorescence detection— Y. Kishimoto et al., J. Chromat., 1982, 231 Biomed. Appl., 20, 121 -127. In plasma or urine sensitivity 1 ng/ml, electrochemical detection—R. C. Causoneta/., J. Chromat., 1984, 306 Biomed. Appl., 31, 257-268. 

High Pressure Liquid Chromatography. In plasma sensitivity 5 ng/ml, electrochemical detection—R. F. Suckow et al., J. pharm. Sci., 1982, 71, 889-893. 

High Pressure Liquid Chromatography. In serum electrochemical detection—P. Surmann, Arch. Pharm. Bert, 1980,313, 1052-1054. 

Quantification. High Pressure Liquid Chromatography. In whole blood, plasma or urine sensitivity 75 ng/ml for plasma and urine, 450 ng/ml for whole blood, electrochemical detection—R. F. Bergstrom et ai, J. Chromat., 1981, 222 Biomed. AppL, 77, 445-452. In serum sensitivity 130 ng/ml, fluorescence detection—E. P. Lankmayr et al., J. Chromat., 1981, 222 Biomed. AppL, 11, 249-255. 

High Pressure Liquid Chromatography. In serum or urine detection limit 10 ng/ml, electrochemical detection—L. Nord-holm and L. Dalgaard, J. Chromat., 1982, 233 Biomed. AppL, 22, 427-431. In serum or urine detection limit 100 ng/ml, UV detection—R. Gochin et al, J. Chromat., 1981, 223 Biomed. AppL, 12,139-145. 

Sodum, R.S., Fiala, E.S. (2001). Analysis of peroxynitrite reactions with guanine, xanthine, and adenine nucleosides by high-pressure liquid chromatography with electrochemical detection C8-nitration and oxidation. Chem. Res. Toxicol. 14 438-50. 

High pressure liquid chromatography with electrochemical detection has been used for castanospermine, 1-deoxynqjirimycin, 1-deoxymannojirimycin and swainsonine using a cation exchange column. With this technique it was possible to detect the compounds when added to urine and plant extracts [119],... 

DNP = dinitrophenol ELCD = electrochemical detection FID = flame ionization detection GC = gas chromatography HPLC = high pressure liquid chromatography HRGC = high resolution gas chromatography MS = mass spectrometry PAD = pulse amphrometric detection PID = photodiode array detection UV = ultraviolet detection... 

Pitts, N. I., Deftereos, D. and Mitchell, G. Determination of succinylcholine in plasma by high pressure liquid chromatography with electrochemical detection. Br. J. Anaesth. 85,592-598 (2000). 

For analytical purposes cholesterol oxidase has been immobilized on various carriers (Table 6). Electrochemical, optical, and calorimetric indication have been used as detection methods. Combination of a thermistor-coupled flow-through system with immobilized COD permitted the measurement of 0.03-0.15 mmolA cholesterol (Mattiasson et al., 1976). Ogren et al. (1980) described an immobilized COD reactor for the analysis of steroid fractions obtained by high pressure liquid chromatography. The UV absorption at 240 nm of enzymatically formed cholestenone was used as the measuring signal. Linearity was found between 10 and 80 pmol/1. 

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