HPLC report chemical structure

FIGURE 13 An HPLC report using mass detection and chemical structure libraries. 

To improve the separation of the derivatives of fatty acids with the same effective carbon number, e.g., palmitoleic (C16 1), linoleic (18 2), andmyristic (C14 0), Baty et al. (33) reported the preparation of the anthrylmethyl esters derivatives of several fatty acids (with 9-hydroxy-methylanthracene and the catalyst 2-bromo-l-methylpyridinium iodide (BMPI)) with a view to analysis by HPLC and LC-MS (with gradient elution on a ZORBAK 5-/zm Cl8 column) (see Chemical Structure 1). The excess reagents were evaporated under nitrogen at 50°C, and the de-rivatized acids were taken up in 1 ml of mobile phase prior to chromatography. This method did not allow the resolution of the C16 1, 08 2, and C14 0 esters, although HPLC data obtained for the other acids correlated well with that obtained by capillary gas-liquid chromatography. 

The comparison of three coumarin compounds, 4-(bromomethyl)-7-methoxy-coumarin (Br-MMC), 7-(diethylamino)coumarin-3-carbohydrazide (DCCH), and 7-(diethylamino)-3-[(4-(iodoacetyl)amino)phenyl]-4-methylcoumarin(DCIA) as potential chemiluminescence with HPLC was reported by Grayeshi and Vasto (35) (see Chemical Structure 2). 

Highly purified esters were obtained by preparahve HPLC [5, 17]. The chemical structure of the purified monoesters was determined by and H nuclear magnetic resonance (NMR) and their molecular masses were determined by a mass spectroscopy (MS) technique as reported elsewhere [5, 17]. 

Lyngbyatoxin A (34) was isolated from a Hawaiian L. majuscula strain by a combination of size exclusion chromatography and HPLC, and its structure elucidated by the analysis of and NMR data, spin-spin decoupling experiments, and chemical derivatization to the acetate and the tetrahydro derivative. Two oxidized derivatives, lyngbyatoxins B (35) and C (36), were reported in 1990 from another L. majuscula specimen collected from the same beach as the initial lyngbyatoxin A producer. Interestingly, 34 was also isolated from Streptomyces sttavas and is known as teleocidin A-1. ... 

The dimethylarsinoyl derivative of sulfated ribitol (see Fig. 2, compound 15) was isolated from the red alga Chondria crassicaulis (38). It had been observed as a major arsenical in C. crassicaulis by high performance liquid chroma-tography-inductively coupled plasma mass spectrometry (HPLC-ICPMS), and was initially reported as an unknown because it did not match any available standard (39). Subsequently, the compound was isolated and a chemical structure was proposed chiefly on nuclear magnetic resonance (NMR) data chemical synthesis of authentic material confirmed the proposed structure (38). This com-... 

Other Examples of the Use of Principal Properties Characterization by principal properties has been reported for classes of compounds in applications other than organic synthesis Aminoacids, where principal properties have been used for quantitative structure-activity relations (QSAR) of peptides [64], Environmentally hazardous chemicals, for toxicity studies on homogeneous subgroups [65]. Eluents for chromatography, where principal properties of solvent mixtures have been used for optimization of chromatographic separations in HPLC and TLC [66],... 

A detection technique(s) capable of producing chemical information specific to the molecular structure of each individual organic impurity at sensitivities matching those of the reporting analytical technique/method (e.g., HPLC/UV and GC/FID). 

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