This paper is the second of a series dealing with the analysis of penicillin by means of a chromatogram using solvent-phosphate buffer partition on a silica base. The first paper (Levi, 1948) described the development of this type of chromatogram which is based on that ofMartin & Synge (1941), and outlined the principles of its application to the study of penicillin. The work described was carr...

An improved mass defect filter (MDF) method employing both drug and core structure filter templates was applied to the processing of high resolution liquid chromatography/mass spectrometry (LC/MS) data for the detection and structural characterization of oxidative metabolites with mass defects similar to or significantly different from those of the parent drugs. The effectiveness of this approa...

The development of a technique combining solid-phase microextraction (SPME) with microbore high-performance liquid chromatography (micro-HPLC)-tandem quadrupole time-of-flight (QTOF) mass spectrometry (MS) for determination of dissolved microcystins in water is reported. Several important parameters affecting the efficiency of SPME extraction of microcystins are investigated. A microbore C18 co...

BACKGROUND Analysis of exhaled breath, especially of volatile organic compounds (VOCs), is of increasing interest in the diagnosis of lung cancer. Compared with other methods of breath analysis, ion mobility spectrometry (IMS) offers a tenfold higher detection rate of VOCs. By coupling the ion mobility spectrometer with a multicapillary column as a pre-separation unit, IMS offers the advantage ...

The direct sequencing of PCR products generates heterozygous base-calling fluorescence chromatograms that are useful for identifying single-nucleotide polymorphisms (SNPs), insertion-deletions (indels), short tandem repeats (STRs), and paralogous genes. Indels and STRs can be easily detected using the currently available Indelligent or ShiftDetector programs, which do not search reference seque...

We describe a procedure for treatment of thin-layer chromatographic serum lipid patterns so that they may be stained by dyes for evaluation by densitometry. After development of the chromatogram [Clin. Chem. 18, 384 (1972)] the plates are dried and sprayed with butyryl chloride. This esterifies the free cholesterol. After drying, the plate is treated with iodine monobromide, to add iodline to t...

BACKGROUND Atractylodis rhizoma is one of the most often used drugs in traditional Chinese medicine. Stir frying with wheat bran is the most common processing method. To clarify the principle of processing, an experiment was carried out to compare the tissue distribution of typical constituent after oral administration of raw A. rhizoma and processed ones. OBJECTIVE To compare the tissues dis...

Selected reaction monitoring (SRM) is a powerful tandem mass spectrometry method that can be used to monitor target peptides within a complex protein digest. The specificity and sensitivity of the approach, as well as its capability to multiplex the measurement of many analytes in parallel, has made it a technology of particular promise for hypothesis driven proteomics. An underappreciated step...

Direct injection for gas chromatographic profi ling of alcoholic beverages is usually preferable, but where spirits and liquors contain appreciable amounts of non-volatile material, some mode of pre-treatment may be required to avoid both inlet and column contamination. This consideration applies in particular to products aged for extended periods in wooden barrels and especially products conta...

Background: Analysis of exhaled breath, especially of volatile organic compounds (VOCs), is of increasing interest in the diagnosis of lung cancer. Compared to other methods of breath analysis, ion mobility spectrometry (IMS) offers a ten-fold higher detection rate of VOCs. By coupling the ion mobility spectrometer with a multi-capillary column as a pre-separation unit, IMS offers the advantage...