Only Optimists Work at Sartorius! Practical Experience of Stress Management in a Pandemic
Estimation of Measurement Uncertainty During Calibration of Laboratory Metering Devices In accordance with the requirements of GOST ISO / IEC 17025-2019 General requirements for the competence of testing and calibration laboratories, a laboratory performing calibration, including its own equipment, must assess the measurement uncertainty for all calibrations. The article describes an algorithm for estimating measurement uncertainty in the calibration of laboratory metering devices. In particular, we consider the measurement uncertainty budget for calibration of a Proline Mechanical Pipette BIOHIT Sartorius pipette dispenser with a variable dosing volume.
The Use of Isocratic HPLC in Reverse Phase and Hydrophilic Modes for the Group Determination of Antibiotics of Various Classes Chromatographic conditions for isocratic HPLC determination in reverse phase and hydrophilic modes of a number of widely used antibiotics are described. In particular, examples are given of the group separation of sulfamides, quinolones and cephalosporins, as well as a set of antibiotics used in veterinary medicine, including nitroimidazoles, lincosamides, tetracyclines, sulfonamides and quinolones. It is argued that the widespread use of gradient elution for HPLC determination of antibiotics (to the detriment of the more practical isocratic approach) is mainly due to the use of insufficient quality stationary phases, as well as stationary phases with suboptimal selectivity. The results are illustrated with real examples of HPLC separations developed by specialists of the IP company Sychev KS / I.B.S.
multiple broken total internal reflection
Ultimate Solution for Accurate Cement Phase Analysis A method of combined phase analysis with preliminary determination of the elemental composition of polycrystalline materials using the Smart X–Combo system, consisting of two bench-top instruments: a wave-dispersive X-ray fluorescence spectrometer (XRF) and an X-ray diffractometer (XRD), is presented. A comparison is made with the traditional phase analysis, which uses calculations by the Boge method. Using the example of Portland cement, the advantages of an integrated approach to assessing the phase composition of powder samples are shown.
Features of the Definition of Qualitative Properties. Laboratory Requirements In 2017, a new edition of the international standard was adopted, which was translated into Russian and entered into force in 2019 – GOST ISO / IEC 17025-2019 Conformity assessment. General requirements for the competence of testing and calibration laboratories. The issues of determining the nominal properties of an object, which do not have units of measurement, are discussed. The nominal properties can be determined are listed. It is noted that a general methodology for determining nominal properties has not been developed, therefore, individual successful attempts to establish a unified approach to methods for determining specific types of nominal properties do not solve the problem as a whole. As a result, the standards contain descriptions of techniques that obviously cannot be considered sufficiently complete. Recommendations for the verification of methods for determining nominal properties in testing laboratories are given.
Project of the Department of Chemistry of Lomonosov Moscow State University and the Polytechnic Museum. From the History of Gas Chromatography Instrumentation in the 1940s – early 1970s. Part 1 In 2020 several issues of the magazine Analytics (No. 2 and 4) contained information about the new project of the Chemistry Department of Moscow State University and the Polytechnic Museum, which is dedicated to the attribution of artifacts by students of the Department studying the history of chemistry. During the organization of the Polytechnic Museum’s collections in terms of the prospects for their development, it is of great interest to clarify the place of the material sources presented in its in the context of considering the evolution of chromatographic equipment. This article is devoted to historical investigation of appearance in the domestic market of analytical equipment of the laboratory gas chromatograph LHM 8MD (it was put into mass production in 1972 by the factory Mosneftekip), which is one of the exhibits of this collection. In this regard part 1 describes the formation and development of instrument making in the field of gas chromatography abroad for the period 1940s – 1960s.