摘要:
An apparatus and related method for optical calibration of spectrophotometers is described. The apparatus is a calibration plate including one or more cuvettes filled with solutions of interest. The cuvettes are sealed to prevent evaporation. The cuvettes also possess a compressible component to allow for expansion of the solution and a bubble control apparatus to ensure that the compressible component does not intersect the beam path. A piece of neutral density glass is optionally included in the apparatus to track optical changes of the solutions over time.
摘要:
A system and related method for determining the volume of a sample solution delivered by a liquid delivery device. The system includes devices for adding and removing diluent, the sample solution under analysis and a mixture of the two in a cell having a substantially constant cross sectional area and a known horizontal optical path length. The system includes one or more spectrophotometers to measure horizontally and vertically absorbance associated with two distinct chromophores. A first chromophore of unknown concentration is in the diluent and a second chromophore of known concentration is in the sample solution. The method determines absorbance horizontally and vertically of the first chromophore prior to adding the sample solution and then determining absorbance of the first chromophore horizontally and vertically and the second chromophore horizontally after mixing the diluent and sample solution together. That information is used to determine the volume of the sample solution added to the cell.
摘要:
A system and related method for determining the volume of a sample solution delivered by a liquid delivery device. The system includes devices for adding and removing diluent, the sample solution under analysis and a mixture of the two in a cell having a substantially constant cross sectional area and a known horizontal optical path length. The system includes one or more spectrophotometers to measure horizontally and vertically absorbance associated with two distinct chromophores. A first chromophore of unknown concentration is in the diluent and a second chromophore of known concentration is in the sample solution. The method determines absorbance horizontally and vertically of the first chromophore prior to adding the sample solution and then determining absorbance of the first chromophore horizontally and vertically and the second chromophore horizontally after mixing the diluent and sample solution together. That information is used to determine the volume of the sample solution added to the cell.
摘要:
A system and related method for improved liquid delivery evaluation uses a solution containing one or more dyes such that the solution exhibits multiple distinct detectable light absorbance spectral features for calibrating or testing over extended volume or dilution ranges. The system includes: a photometric instrument capable of measuring optical absorbance at multiple wavelengths; a sample solution to be dispensed using the liquid delivery system whose performance is being tested or calibrated; and vessels with diluent solution. The sample solutions contain a dye, chosen so that multiple distinct detectable light absorbance spectral features can be distinguished for volume or dilution ranges of interest. The concentrations of the dyes may be chosen so that a large volume delivery device, and a small volume delivery device, are calibrated with the same sample solution but using a different spectral feature with a high absorbance per unit pathlength.
摘要:
L'invention concerne des procédés et un appareil permettant de déterminer avec précision le volume d'une pipette à l'aide d'un photomètre. Un système de réactif utilisé avec le photomètre comprend un premier récipient contenant une solution de référence et au moins un second récipient contenant une solution échantillon. Le récipient contenant la solution de référence ayant une absorbance maximale à une première longueur d'onde est positionné dans le photomètre. Les absorbances du récipient à la première longueur d'onde et à une seconde longueur d'onde sont mesurées. Ensuite, la longueur de chemin optique du récipient à la seconde longueur d'onde est calculée à partir des absorbances mesurées à la première et à la seconde longueurs d'onde. Une partie aliquote de la solution échantillon est introduite dans le récipient à l'aide d'une pipette que l'on désire étalonner. La solution échantillon possède une absorbance maximale à la seconde longueur d'onde. La solution échantillon est mélangée à la solution de référence pour former un mélange. Ensuite, l'absorbance du mélange dans le récipient est mesurée à la seconde longueur d'ondes. Le volume de la partie aliquote est calculé à partir de l'absorbance du mélange et de la longueur de chemin optique du récipient. Le volume de la partie aliquote représente le volume de la pipette.
摘要:
A system and related method for determining the volume of a sample solution delivered by a liquid delivery device. The system includes devices for adding and removing diluent, the sample solution under analysis and a mixture of the two in a cell having a substantially constant cross sectional area and a known horizontal optical path length. The system includes one or more spectrophotometers to measure horizontally and vertically absorbance associated with two distinct chromophores. A first chromophore of unknown concentration is in the diluent and a second chromophore of known concentration is in the sample solution. The method determines absorbance horizontally and vertically of the first chromophore prior to adding the sample solution and then determining absorbance of the first chromophore horizontally and vertically and the second chromophore horizontally after mixing the diluent and sample solution together. That information is used to determine the volume of the sample solution added to the cell.