Calibration curve

About: Calibration curve is a research topic. Over the lifetime, 6552 publications have been published within this topic receiving 95128 citations.

Biochemical analysis apparatus and method for correcting the results of biochemical analyses

Abstract: of EP0383322A biochemical analysis apparatus comprises a movement device which moves analysis media (2) containing a reagent or an electrochemical sensor, which will interact with a specific biochemical substance contained in liquid samples (36) and give rise to changes in the analysis media, along a movement path connecting an introducing section (3) and an ejecting section (40). While the analysis media are present in the movement path, a measurement device (16, 50) measures changes which have occurred in analysis media. A reading device (18) reads information about correction values (18a), which are to be used in order to correct a calibration curve so that it becomes suitable for analysis media used in analyses, from a correction value recording medium (1). A correction device (6) corrects the calibration curve on the basis of the correction values. An operation device (7) uses the corrected calibration curve in order to determine the concentration or the activity of the specific biochemical substance in a liquid sample from the value measured by the measurement device.

A hydrogel-based solidification method for the direct analysis of liquid samples by laser-induced breakdown spectroscopy

Abstract: Laser-induced breakdown spectroscopy (LIBS) is a simple, fast, and direct technique for the elemental analysis of various samples. However, the practical application of this method in direct liquid analysis is limited due to its inherent disadvantages including surface ripples and extinction of emitted intensity. Applicable treatments of liquids always involve complicated procedures or additional instruments, which is disadvantageous to its analytical performance. In this study, we proposed a novel method for the LIBS analysis of liquid samples via a hydrogel-based solidification technique. In this new method, aqueous solution is directly poured into sodium polyacrylate resins. Owing to the high hydroscopicity of sodium polyacrylate resins, the resins quickly form a hydrogel and immediately solidify the liquid samples. After this, the LIBS analysis is directly performed. To estimate the analytical performance of this proposed method, calibration curves were established and limits of detection for Al, Cu, and Cr were obtained. The limits of detection (LODs) for the emission lines of Al(I) 308.21 nm, Cu(I) 324.75 nm, and Cr(I) 425.43 nm were 0.460 μg mL−1, 4.69 μg mL−1, and 4.44 μg mL−1, respectively. According to the obtained results, this proposed method demonstrates its better analytical performance in terms of LODs at the ppm level and requires shorter processing time as compared to other analytical methods based on the LIBS technique for liquid sample analysis. Especially, the short pretreatment of samples and simple auxiliary equipment make this hydrogel-based solidification method bring LIBS out of the laboratory for the direct analysis of environmental liquid samples. The feasibility and potential of this novel method have also been discussed for special analytical applications in slurry samples.

Use of flow cytometry and SNARF to calibrate and measure intracellular pH in NS0 cells.

Abstract: Background Two calibration methods have been proposed for determining the relation between the fluorescence ratio of a pH-sensitive fluorescent indicator and intracellular pH (pHi). The first method uses nigericin to clamp pHi to external pH (pHe) and the second is the null point method. We compared these different calibration methods, solution conditions, and temperatures by using flow cytometry and the fluorescent dye 1,5- (and-6)-carboxy seminaphtorhodafluor-1-acetoxymethyl ester with an NS0 cell line. Methods The nigericin method was performed in glucose solutions supplemented with KCl and 2-(N-morpholino)ethane sulphonic acid plus tris(hydroxymethyl)aminomethane (solution 1A), a mixture of K2HPO4/KH2PO4 in glucose-solution supplemented solutions (solution 2A), or bicarbonate buffered growth medium supplemented with K2HPO4/KH2PO4 (solution 2B); this allowed a range of pHe values to be used. The effect of temperature (22°C or 37°C) on the nigericin calibration curve was also investigated. The null point method was performed by using a series of solutions with a mixture of weak acid and base with a known pHi response. Results Using solution 1A as the calibration solution resulted in acidic values of pHi for cells cultured in medium as compared with the values achieved with solution 2A. Using solution 2B did not affect the calibration curve. For the temperatures considered in this study, there was no affect on the calibration curve, but temperature did affect the pHi value of cells in phosphate buffered saline. The pseudo-null point method used with flow cytometry resulted in a calibration curve that was significantly different (P < 0.05) from that achieved using the nigericin method. Conclusions Our data indicates that the choice of calibration solution can affect the reported pHi value; therefore, careful choice of solution is important. © 2005 Wiley-Liss, Inc.

System and method for calibration of a flow device

Abstract: Embodiments of the present invention provide a system (200) and method for rapid calibration of a flow device (30) A flow device can be provided with a calibration flow curve (eg, represented by an nth degree polynomial) by the manufacturer or a third party The calibration curve can be adjusted for a process fluid and the system for which the flow device is actually installed using one or more correction factors The correction factors can be determined for the flow curve based on a simple empirical test or fluid properties of the process fluid The corrected flow curve is then saved at the flow device so that it can be used for future flow control