Organogenic elements and compounds in surface samples from the sea of tranquillity.

Organogenic elements, mainly carbon, nitrogen, phosphorus, and sulfur are present in the particulate material and in a breccia rock from Tranquillity Base in amounts ranging from 5 to 4200 parts per million. The major compounds of carbon released by heating are carbon monoxide and carbon dioxide; the former predominates. Small amounts of other compounds of carbon have also been observed. Sulfur can be released as hydrogen sulfide by treatment with acid. The carbon isotopic delta(13L)C values are definitely nonterrestrial (+ 13 to + 18.5 per mil).

The determination of steroids with and without natural electrophores by gas chromatography and electron-capture detection.

The response of the electron-capture detector to organic compounds is poorly defined, and the steroids are no exception to this observation. For those steroids which are naturally electron-capturing, the structures of the electrophores will be defined. Other steroids can be made electron-capturing by the formation of appropriate derivatives. Some new or infrequently used reagents for this purpose (flophemesyl ethers, t-bulflophemesyl ethers, pentafluorophenylhydrazone derivatives and halogen-substituted aromatic boronic acids) are described.

Artifacts in chromatography: an overview.

A brief overview of the field of analytical artifacts is provided, with examples of solvent impurities, stabilizers, polymer additives, and problems relating to Teflon, glassware, and laboratory contaminants.

Volatile organic components in the Skylab 4 spacecraft atmosphere.

The volatile organic components in the spacecraft cabin atmosphere of Skylab 4 were trapped on a solid adsorbent at various times during the mission. In post-flight analyses, more than 300 compounds in concentrations from less than 1 ppb up to 8000 ppb could be detected by high-resolution gas chromatography. In the samples of the 11th, 47th, and 77th day of the mission, approximately 100 components in the molecular weight range of 58 to 592 were identified by mass spectrometry. Besides components known from other environments, such as alkanes, alkenes, and alkylated aromatic hydrocarbons, components typical for the human metabolism such as ketones and alcohols were found. Other typical components in the spacecraft atmosphere are fluorocarbons (freons) and various silicone compounds, mostly normal and cyclic methylsiloxanes.

Column elution and concentration of volatile compounds in biological fluids.

A new solvent elution method is described for the isolation and concentration of volatile metabolites in biological fluids. The procedure involves elution of the sample with a solvent through a micro-column of an adsorbent into glass-wool and evaporation of the excess solvent in a stream of helium at room temperature. The volatiles are revocered by subsequent heat desorption into a chromatogrpaphic system. Both elution and evaporation are made in a single step using a novel sampling device. Since the technique is based on liquid-solid adsorption chromatography, the adsorbent-solvent system which gives the maximum yield of volatile constituents was studied. The method is simple, highly efficient and reproducible, requiring only small volumes of biological fluids (less than 100 mul).

A micro method for the determination of volatile metabolites in biological samples. A preliminary report.

A new method for analyzing volatile metabolites in biological fluids and tissues has been developed. The procedure involves extraction of the sample with diethyl ether, concentration on a short column of glass wool by elution of the diethyl ether, then thermal desorption of the trace constituents into a chromatographic system. Small samples of 100 mul are quite adequate. The method is applicable to serum, plasma, urine and other fluids. Small tissue samples can also be used with this technique.

The determination of sucrose in molasses by high-performance thin-layer chromatography.

A method is described for the determination of sucrose in molasses by high-performance thin-layer chromatography. A baseline separation of sucrose is achieved in about 40 min using acetone--water (90:10) as developing solvent. The relative standard deviation of determinations by this method is about 2.2%. Results agree with those obtained by isotope dilution analysis of the same molasses samples.

Gas chromatographic-mass spectrometric analysis of volatile constituents in saliva.

Present methods for the development of metabolic profiles are limited to the use of headspace techniques and solvent extraction methods. A new method for the development of saliva profiles which provides information complementary to existing analyses has been developed. The results of the developed methodology provide a reliable, reproducible method for metabolic profiling. Gas chromatographic-mass spectrometric analysis of the volatile constituents provided positive identification of 39 compounds. Application of the developed protocol toward the investigation of saliva as a vehicle for the non-invasive detection of certain pathological states, specifically diabetes mellitus and liver disorders, may be possible.

Profiles of volatile metabolities in body fluids.

A method for the analysis of volatile metabolites present in plasma, urine, breast milk and amniotic fluid collected from mother-infant pairs has been developed which requires only 100 mul of plasma, 3 ml of urine, 20 mul of breast milk and 500 mul of amniotic fluid. After extraction with diethyl ether, the volatile compounds were absorbed on glass wool in a special concentration tube and subsequently desorbed and transferred to a 100-m nickel capillary column for analysis by gas chromatography and gas chromatography-mass spectrometry. The separations, carried out by temperature programming, were complete in 90 min.

The determination of bifunctional compounds. IX. A selective reaction for the determination of guaifenesin in plasma by gas chromatography.

Guaifenesin after extraction from plasma with an organic solvent can be selectively derivatized with 2,4-dichlorobenzeneboronic acid and determined by gas chromatography with electron-capture detection. The detection limit for guaifenesin was 15 ng ml-1 for a 2.0-ml plasma sample. The mass spectra of the boronate derivatives of guaifenesin and mephenesin, used as internal standard, show good molecular ions with characteristic modes of fragmentation useful for their identification.

Methionine dipeptide stationary phases for the resolution of enantiomers.

N-Trifluoroacetyl-L-methionyl-L-methionine cyclohexyl ester as well as the disulfide and disulfone derivatives of this phase have been synthesized. The methionine phase exhibits improved properties as a stationary phase for the separation of amino acid enantiomers as compared to other dipeptide stationary phases and can be used at temperatures ranging from 70 to 150 degrees. The sulfoxide phase, however, was incapable of resolving the enantiomeric derivatives. Physical properties of the sulfone compound limit its use as an effective resolving agent.

The role of organic volatile profiles in clinical diagnosis.

The organic volatile constituents of biological fluids contain clinically useful diagnostic information for the recognition of metabolic disorders in man. To gain access to this information, it was necessary to develop the methodology for reproducibly stripping the trace concentrations of volatiles from biological fluids (dynamic headspace, gas phase-stripping, solvent extraction, and the transevaporator technique), to separate the complex extracts by high-resolution capillary column gas chromatography, and to develop computer-aided data-handling and pattern-recognition techniques for analyzing the immense amount of information generated. The normal and pathological organic volatiles identified by gas chromatography--mass spectrometry in urine, serum, and breast milk are tabulated. Clinical applications of the above techniques to the study and diagnosis of diabetes mellitus, respiratory virus infection, renal insufficiency, and cancer are described.

Simultaneous determination of antiarrhythmia drugs by high-performance thin-layer chromatography.

A method is described for the determination of antiarrhythmia drugs in serum by high-performance thin-layer chromatography. Baseline separations are achieved for all the drugs and clozapine, an internal standard, in two developments with solvents of different polarity. Lidocaine and diphenylhydantoin are scanned at 220 nm after the first development. Procainamide, propranolol and quinidine are scanned at 290 nm after the second development. The relative standard deviation of the determination varies between 3 and 14% depending on the nature of the drug and its concentration.

Solid-phase extraction of chloramphenicol with graphitized carbon black.

The sorption and desorption properties of graphitized carbon black (GCB) were evaluated for enrichment of highly polarizable chloramphenicol (CP) from biological fluids. The distribution of CP between GCB and water lay strongly toward GCB. Among the organic solvents examined, methanol gave the lowest adsorption coefficient. The optimum packing amount of GCB, and the optimum volume and flow-rate of the eluent were deduced from the breakthrough curve and methanol elution curve, respectively. The inner diameter of GCB extraction columns was chosen from the sorption efficiency curve obtained by plotting CP recovery against column inner diameter. The solid-phase extraction method using GCB was applied to the assay of CP in serum samples in the concentration range of 5 to 50 micrograms/ml.

Paraffinic hydrocarbons in the Orgueil, Murray, Mokoia and other meteorites.

Small samples of the Orgueil (Wiik Type I), Murray (Wiik Type II), Mokoia (Wiik Type III) and other meteorites (Alais, Ivuna, Al Rais, Bells, Cold Bokkeveld, Mighei, Nogoya, Santa Cruz, Grosnaja, Kaba, Lance, Ornans, Chainpur, Karoonda, Warrenton, and St. Caprais) were extracted with organic solvents, fractionated by silica gel chromatography, and analyzed by gas chromatography and by a new gas chromatographic-mass spectrometric technique. Only the high molecular weight hydrocarbons eluted by n-heptane were analyzed. The following observations were made: All meteorites contain paraffinic hydrocarbons in varying amounts and with a certain distribution. Normal and isomeric alkanes from Cl5 to about C25 with a maximum at C19-C21 were found in the Orgueil, Murray and Mokoia meteorites. Pristane and phytane, two saturated polyisoprenoid hydrocarbons, known to be degradation products of chlorophyll, were found in all meteorites except the Ornans, although in several (Type I and Type III, except Mokoia) the amounts were very small. No predominance of odd over even carbon-number hydrocarbons was observed except in the C22-C27 normal alkane range of some samples of the Orgueil. The concentration of alkanes in certain samples of the Orgueil was found to be about one order of magnitude lower than in others indicating a significant heterogeneity in the distribution of hydrocarbons. Practically all the meteorites of Type II and some of Type III (Mokoia) gave an essentially identical or very similar hydrocarbon chromatographic pattern, indicating a common origin for the hydrocarbons. The distribution of paraffinic hydrocarbons, including pristane and phytane, in some of these meteorites was found similar to that of microfossil-bearing pre-Cambrian rocks 2 x 10(9) years old or older. The Orguiel was similar to the Gunflint chert and Type II meteorites were similar to the Soudan rock. It remains to be seen whether these hydrocarbons were formed on the earth-moon system as suggested by Urey, on the asteroids, in the solar nebula, or whether they may be the result of a unique terrestrial contamination process.

High-performance thin-layer chromatographic determination of psychopharmacologic agents in blood serum.

High-performance thin-layer chromatography affords a rapid, sensitive method for determination of psychopharmacologic agents in blood serum samples. Quantitation of the representative drugs chlorpromazine, amitriptyline, nortriptyline, imipramine, and desipramine at levels as low as 5 ng/ml is demonstrated by scanning the developed thin-layer plates with a chromatographic spectrophotometer in the ultraviolet absorption mode. Neither derivatization prior to, nor color development after chromatographic separation is required to achieve sensitivity and reproducibility of determinations.

Identification of dihydrothiazoles in urine of male mice.

The compounds 2-isopropyl-4,5-dihydrothiazole and 2-sec-butyl-4,5-dihydrothiazole were identified in urine of male mice. Their excretion in mouse urine is sex-dependent. In the urine of female mice the two dihydrothiazoles are either absent or present only in trace amounts. The analytical procedure includes the adsorption of the volatile mouse urine constituents on Tenax GC, their gas chromatographic separation and the detection of the sulfur compounds by the sulfur-specific detector. The identified compounds were synthesized. Natural and synthetic compounds had the same mass spectrometric properties and retention data.

Capillary column gas chromatographic profile analysis of volatile compounds in sera of normal and virus-infected patients.

Using a transevaporator sampling technique, the volatile profiles from 70 microliter of serum were obtained by capillary-column gas chromatography. The complex chromatograms were interpreted by a combination of manual and computer techniques and a two-peak ratio method devised for the classification of normal and virus-infected sera. Using the K-nearest neighbor approach 85.7% of the unknown samples were classified correctly. Some preliminary results indicate the possible use of the method for the assessment of virus susceptibility.