A highly reproducible procedure was developed for gas-liquid chromatographic analysis of trimethylsilyl derivatives of normal human cerebrospinal fluid. Fourteen normal human cerebrospinal fluid samples tested with this procedure contained alpha- and beta-glucose as well as isomers of two unidentified sugars. Chromatographic changes in three cases of meningeal inflammation (two cryptococcosis a...

an important property that has been extensively studied in quantitative structure activityrelationship (qsar) is the chromatographic retention index. qsar study is suggested for theprediction of retention index of alkanes and alkenes compounds. modeling of the retention indexof alkanes and alkenes compounds as a function of molecular structures was established bydifferent chemometrics methods. ...

The analytical evaluation is described of a [125I]-aldosterone radioimmunoassay method for measuring aldosterone in human plasma, which requires no chromatographic purification before quantification by radioimmunoassay but does require organic solvent extraction. Rabbit anti-aldosterone serum is used, generated against aldosterone-3-oxime coupled to thyroglobulin. The antibody demonstrates negl...

The simple and easy performed automated method for the IR determination of petroleum products (PP) in water using extraction-chromatographic cartridges has been developed. The method assumes two stages: on-site extraction of PP during a sampling by using extraction-chromatographic cartridges and subsequent determination of the extracted PP using sequential injection analysis (SIA) with IR detec...

A high-performance liquid chromatographic (HPLC) assay suitable for the evaluation of 3-methoxy-4-hydroxyphenylglycol (MHPG) in 1-ml aliquots of plasma is presented. Preparatory steps include extraction into ethyl acetate and minicolumn chromatography. Recoveries are monitored with [3H]MHPG. The HPLC procedure utilizes a C18 column, isocratic elution and amperometric detection. The assay was ch...

A simplified radioimmunoasay procedure is described for determination of free ovarian steroids in plasma or serum. Ether extracts were chromatographed on a Sephadex LH-20 column equilibrated with benzene-methanol (85:15 by vol) and estrone, estradiol, estriol, progesterone, and llcw-hydroxyprogesterone were resolved from each other. With relatively specific antibodies, all five hormones were sp...

This article describe the applicability of 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2].2Cl) as a green, versatile and Brönsted acidic ionic catalyst in the promotion of the synthesis of phthalazine derivatives via one-pot three component reaction between aromatic aldehydes, 1,3-diketone derivatives and phthalhydrazide under solvent-free reaction cond...

L-Carnitine is used extensively in functional foods and food supplements; consequently, the control of its enantiomeric purity is of paramount importance. A new derivatization procedure and chiral gas chromatographic method with flame ionization detection, using a cyclodextrin based stationary phase, enables prompt, simple, and inexpensive screening of the enantiomeric ratio of L- and D-carniti...

We have developed a reversed-phase liquid-chromatographic procedure for simultaneously determining phenylalanine and tyrosine in serum and eluates of dried blood spots. Batch derivatization with phenylisothiocyanate and a 10-min linear gradient chromatographic assay with ultraviolet absorbance detection provide rapid sample throughput. Interrun precision (CV) is less than 12%; analytical recove...