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Entomopathogenic fungi (EF), in particular the genus Metarhizium, have shown success in the control of insect pests. However, only a few have been commercialized mainly due to problems associated with the registration schedule, with emphasis on the lack of mandatory specific data requirements for the detection of secondary metabolites. In this study destruxin production for Metarhizium strains BIPESCO5, EAMa 01/58-Su, ARSEF 23 and ART 2825 was determined with an improved method of ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), which has shown high precision in the detection and quantification of dtxs in four culture media (CM, MM, CN2 and OSM) representing different stress conditions. Every 3 days samples were taken for analysis over 18 days that allowed detecting 15 dtxs, with dtx A and B as the most abundant. However, very significant differences among strains in dtxs production were detected, and for each strain, dtxs production was highly dependent on culture medium, which highlights that the selection of a suitable medium for strain production for the risk assessment of secondary metabolites produced by EF is mandatory. [ABSTRACT FROM AUTHOR]

Flow Injection analysis represents an attractive tool because of its great advantages, such as versatility, speed, high sampling rate and wide applicability in the field of pharmaceutical analysis. However, due to the inherent characteristics of the technique, the choice of the best set of operational and chemical conditions is complicated and the conventional univariate optimisation method present some limitations, mainly due to fact that the interdependence of variables is not considered. In relation to the calibration process, because of the transient character of the signals obtained using FIA manifolds coupled with different detection techniques, different strategies can be used in calibration to solve some problems related to the nature of the signal thereby improving the performance characteristics of the method. This paper offers an overview of different methodologies used in optimisation based on the use of statistically designed experiments and some strategies developed for calibration applied to the analysis of pharmaceuticals. [ABSTRACT FROM AUTHOR]

A new sensitive analytical procedure for the determination of albumin is presented, based on the participation of a fluorescent derivative of the protein in the peroxyoxalate chemiluminescent system using imidazole as a catalyst. The chemiluminescent emission is detected in a flow injection analysis (FIA) system, employing micellar medium as carrier, whereas the derivatisation reaction is carried out off-line using fluorescamine as a label. The optimisation of the operational and chemical variables of the method such as concentration of reagents, flow-rates, injection volume, etc., involves the use of experimental designs, including Draper–Lin small composite design, scarcely used in analytical chemistry. The performance characteristics were established and a detection limit of about 0.1 fmol of albumin was obtained. The method has been validated and satisfactorily applied to the determination of albumin in human serum and urine. [ABSTRACT FROM AUTHOR]

An overview of the principles and general applications of analytical pervaporation is presented. The different designs of both the analytical pervaporation module and the continuous manifolds to which the pervaporator is connected are discussed. The versatility of this non-chromatographic continuous separation technique for circumventing some of the shortcomings encountered in the automation of the overall analytical process is shown. Examples of methods developed for samples (both liquid and solid) in the environmental, food and beverage, and clinical and pharmaceutical fields are shown. The potential of pervaporation as an alternative to static and dynamic well-established approaches such as headspace and purge-and-trap sampling prior to gas-chromatographic separation is demonstrated. Examples of this approach involving both solid and liquid samples are discussed. [ABSTRACT FROM AUTHOR]

The supercritical-fluid extraction of vitamins D2 and D3 with carbon dioxide is reported for the first time. The extraction recovery was enhanced by direct addition of diethyl ether to sample contained in the extraction cell. Separation and detection of the analytes was performed off-line by reversed-phase liquid chromatography with UV-detection. The quantification limit of the method is 4.1 μg for both analytes, with precision, expressed as relative standard deviation, of 3.8 and 6.3% for vitamins D2 and D3, respectively (η=7). The proposed method has been applied to the determination of vitamin D in different pharmaceutical products; recoveries were between 85 and 105%. [ABSTRACT FROM AUTHOR]