Mass fragmentography methods

They generally lack sensitivity and a direct relation to molecular structure. GC-MS is fast, direct, and very sensitive, and the spectrum provides a result which puts identification beyond dispute. Computer-assisted systems are now available which embody extensive drug reference libraries and can be automatically searched to identify unknown spectra. The further development of chemical ionization and mass fragmentography methods using stable isotopes now permits very accurate quantitative work. 

Tsukioka et al. [187] determined these contact herbicides in soil by mass fragmentography. The method is based on the reaction of l-benzyl-3-p-polytriazene with an extract of Frenock and Dalapon from strongly acidified sample solutions to form benzylated species. In the analysis of soil samples, steam distillation was applied prior to extraction. Recoveries were >92% and precision <5%. 

H4. Hammer, G.-G., Holmstedt, B., and Ryhage, R., Mass fragmentography identification of chlorpromazine and its metabolites in human blood by a new method. Anal. Biochem. 25, 532-548 (1968). 

Ashraf, J., Butterfield, D. A., Jamefelt, J., and Laine, R. A. (1980). Enhancement of the Yu and Ledeen gas—liquid chromatographic, method for sialic acid estimation Use of methane chemical ionisation mass fragmentography. J. Lipid Res. 21, 1137-1141. 

Bjorkhem, I., Blomstrand, R., Lantto, O., Svensson, L., and Ohman, G. (1976). Towards absolute methods in clinical chemistry Application of mass fragmentography to high-accuracy analyses. Clin. Chem. 22, 1789-1801. 

Gambert, P., Lallemant, C., Archambault, A., Maume, B. F., and Padieu, P. (1979). Assessment of serum cholesterol by two methods gas liquid chromatography on capillary columns and chemical ionisation mass fragmentography with isotope dilution of 3,4-13C-cholesterol as internal standard. J. Chromatogr. 162, 1-6. 

The methods employed for isolation of the alkaloids depend on the nature of the compounds, and specific conditions have frequently been devised for the selective isolation of particular types of compounds. Usually, fresh or dried plant material is extracted with dilute acid solution or with alcohol, and the extract obtained is further fractionated by extraction into organic solvents with variation of pH. Extraction columns (288), membrane processes (425), and ion-exchange materials (288-290) may be particularly useful for subfractionation or isolation procedures. For further identification and isolation of separate compounds, preparative thin-layer chromatography, (288, 291, 292, 426), liquid chromatography (293, 294), or gas chromatography may be used (202, 296, 297). Because some of the products reviewed in this chapter occur naturally in very small amounts, they have not been isolated in crystalline form. Gas chromatography-mass spectrometry (87, 213, 299), mass fragmentography (192), and mass spectrometry-mass spectrometry (301, 359) have proved to be particularly useful techniques for identification of trace alkaloids in complex mixtures. 

The GC/MS procedures for methamphetamine are described in Table 4. The papers published in Japanese - have corresponding reports in English. - - Methamphetamine was detected and determined by mass fragmentography in rat hair after administration of the substance. Nine methods also detected the metabolite amphetamine or amphetamine alone. Suzuki et al. determined methamphetamine also in nail, sweat and saliva. The workup (EX after acid or alkaline hydrolysis) and derivatization technique (methanol-trifluoroacetic acid [TEA]) is rather uniform in most procedures. Nakahara et al. ° used methoxyphenamine excretion into beard hair to discuss several washing procedures. Alkaline or methanolic extraction are used with one exception. Derivatization is mainly made by fluorinated anhydrides. A review ° gives details on analytical procedures, incorporation rates of amphetamines from blood to hair, and relationship between drug history and drug distribution in hair. 

De Graeve et al. described two methods for the papaverine determination in blood samples for pharmacokinetic studies, one utilizing a packed column with 0V-1 1 % and interfaced with a LKB 9000 S mass spectrometer equipped with a multiple ion detector for mass fragmentography,... 

Many analytical problems arise when sensitivity has to be combined with specificity, as in the determination of arachidonic acid metabolites. In fact, the analytical method required for the analysis of these compounds must be sensitive, due to the very low levels of Prostaglandins (PCs) in body fluids and tissues. On the other hand, the method must be specific in order to avoid interferences in the measurement of a single PG such interferences can arise from other PGs or from chemically related compounds (other insaturated fatty acids) present in the same tissues. Several different methods have been set up and are utilized for PGs determinations Bioassay, Radioimmunoassay (RIA) and Mass Fragmentography (MF) are among those commonly used. 

The same sample workup procedure described in Table 2 was used. The data reported in Tables 6 and 7 are raw data obtained in cortex samples of different weight. As it can be seen, MF, Bioassay and RIA gave results of the same order of magnitude. It must be noted, however, that the data for MF are in many cases about twice those obtained by the other methods. It is difficult to attribute a statistical significance to this discrepancy it must be reminded, on the other hand, that only mass fragmentography is able to correct, for each sample, losses due to sample manipulation, since deuterated internal standards are added prior to purification of the sample. 

In a first set of four samples of human urine the results obtained with the three methods are in excellent agreement (Table 8). Mass fragmentography proved to be a less sensitive method than Bioassay or RIA in fact in two samples PGE2 was below the detection limit, even if a larger aliquot of the ethanol extract was used for MF. On the other hand, these low levels were confirmed by RIA. 

PACE ASCIAK CR Deuterium isotope dilution method for the specific measurement of 6-keto-prostaglandin by mass fragmentography. 

A Method for the Estimation of Acetanilide, Paracetamol and Phenacetin in Plasma and Urine Using Mass Fragmentography... 

Validation of Routline Methods for Serum Progesterone Determinations Using Mass Fragmentography Clin. Chim. Acta 65(3) 343-350 (1975) CA 84 56150a-... 

Mass Fragmentography of Creatinine Proposed as a Reference Method Clin. Chem. (Winston-Salem, N. C.) 23 (11) 2114-2121 (1977) CA 88 18526c... 

Assessment of Serum Cholesterol by Two Methods Gas-Liquid Chromatography on a Capillary Column and Chemical Ionization-Mass Fragmentography with Isotopic Dilution [3,4- C]-Cholesterol as Internal Standard J. Chromatogr. 162(1) 1-6 (1979) CA 1348. 90 50804u... 

A Simple Method for the Simultaneous Analysis of Reverse Triiodothyronine and 3,3 -Diiodothyronine by Mass Fragmentography Using GC-MS. II. Mass Fragmentographic Identification of 3,3 -Diiodothyronine and Reverse Triiodothyronine in Biological Fluids... 

Heki, N., Noto, M., and Hosojima, H. An Improved Method for the Simultaneous Analysis of Norepinephrine, Epinephrine and Dopamine at the Picogram Level by Mass Fragmentography... 

Schwertfeger, G., and Rnedel, M. Improved Method for the Quantitation of Serum Phytanic Acid by Glass Capillary Chromatography-Mass Fragmentography... 

A Method for the Identification of Acid Metabolites of Tetrahydrocannabinol (THC) by Mass Fragmentography... 

Evaluation of Three Clinical Chemical Routine Methods for the Determination of Serum Uric Acid, by Mass Fragmentography Clin. Chim. Acta 95(2) 219-226 (1979) CA 91 153866r... 

Sakaguchi, K., Katayama, K., Tsutsumi, J., and Kawabe, K. Determination Method of Bile Acids in Biological Materials by Mass Fragmentography Yakugaku Zasshi 99(4) 421-431 (1979) CA 91 71116g... 

The determination of trimethylsilylated pantoyllactone by gas chromatography-mass fragmentography (GC-MF) with a packed column has been developed for the assay of pantothenic acid by Tarli et al. (23). Umeno et al. (24) used the same method to investigate hopantenic acid levels in serum and urine after administration of calcium hopantenate. 

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