A device for light-based analysis of a substance in a liquid sample comprises: an analysis cell for holding the liquid sample; wherein the analysis cell comprises a first wall portion for passing light generated by a light source into the analysis cell, and a second wall portion for passing light from the analysis cell to a light detector; and a plunger configured for movement along walls of the analysis cell for allowing entry of the liquid sample into the analysis cell and pushing the liquid sample out of the analysis cell; wherein at least one wiper is arranged on the plunger for cleaning the first and second wall portions during movement of the plunger.

A measuring device for determining a substance concentration of a fluid arranged in a measurement volume includes a source emitting a source spectrum, a wavelength-selective means arranged before the measurement volume, a measurement space limiting the measurement volume at least in a beam path, and a detector for measuring a wavelength-related absorption of a measurement spectrum having passes through the measurement volume. A fluorescence-reducing element is arranged in the beam path between the detector and the measurement volume. A beam splitter is arranged between the source and the measurement volume.

An object of the present invention is to provide a skin sensitization measuring reagent, a method for measuring skin sensitization, and a compound that allow the sensitization of a test substance to be measured using a single reagent. According to the present invention, there is provided a skin sensitization measuring reagent including, as a main measuring agent, an organic compound having at least one thiol group derived from an amino acid and at least one amino group derived from a side chain of an amino acid. The organic compound has an absorption spectrum in an ultraviolet, visible, or near-infrared region and has a molar absorption coefficient of 100 L/mol.Math.cm or more and 500,000 L/mol.Math.cm or less at a maximal absorption wavelength.

A method of detecting an amine-based shale inhibitor in a wellbore servicing fluid (WSF) comprising contacting an aliquot of the WSF with an amine detector compound to form a detection solution; wherein the WSF comprises the amine-based shale inhibitor; and wherein the detection solution is characterized by at least one absorption peak wavelength in the range of from about 380 nm to about 760 nm; detecting an absorption intensity for the detection solution at a wavelength within about ±20% of the at least one absorption peak wavelength; comparing the absorption intensity of the detection solution at the wavelength within about ±20% of the at least one absorption peak wavelength with a target absorption intensity of the amine-based shale inhibitor to determine the amount of amine-based shale inhibitor in the WSF; and comparing the amount of amine-based shale inhibitor in the WSF with a target amount of the amine-based shale inhibitor.

A neurosurgery system for resecting tissue after administration of a contrast agent to a patient, the system including an electrosurgical instrument for manipulating tissue which generates a fluid sample from the tissue during ablation, an aspiration channel configured to obtain the fluid sample, an analyzer for analyzing the fluid sample, an indicator configured to provide an indication of the presence of a rare earth metal, and a controller configured to instruct the indicator to provide the indication of the presence of the rare earth metal. The analyzer includes a collector coupled to the aspiration channel and configured to receive a portion of the fluid sample from the aspiration channel, a heater configured to atomize the portion of the fluid sample, and a detector configured to measure an absorption of a wavelength corresponding to a rare earth metal.

A high-sensitivity nanosecond to millisecond transient absorption spectrometer for measurements of miniscule signals under low excitation intensities includes an excitation source generating a >100 Hz, <5 ns pulsewidth excitation pulse for exciting a light absorbing sample, a probe light source for generating a high photon flux probe light beam producing an average irradiance greater than 1 μW m-2 nm-1 for measuring the transient absorption spectrum of the sample before and after excitation by the excitation source, a DC-coupled detector capable of measuring light for enabling synchronous measurement of both the transmission of the probe light beam and the change in transmission of the probe light beam between a signal with the excitation pulse present and a signal in the absence of the excitation pulse, and a digital oscilloscope with a trigger rearm time capable of collecting every trigger event at frequencies including 1 MHz, for enabling sequential noise subtraction protocols.

A method and system for testing a liquid sample for an organic compound is disclosed, the method including the steps of collecting the liquid sample from a liquid source; transmitting light having a wavelength of between about 190 nanometers and about 310 nanometers into the liquid sample; measuring absorption/transmission of the light by the organic compound in the liquid sample; and determining a concentration of the organic compound within the liquid sample based on the absorption/transmission of the light by the organic compound. The system can include a spectrophotometer for measuring the absorption of UV light by the organic compound, an ion exchange column for removing ion contaminants from the liquid sample, and a vacuum degasser unit for removing gases and other impurities from the liquid sample.

An embodiment provides a method for measuring zinc and copper in an aqueous sample, including: reducing an aqueous sample containing an amount of zinc and an amount of copper with a reducing agent; buffering the reduced aqueous sample; chelating the amount of copper in the buffered aqueous sample with a copper(I) chelating agent; measuring the amount of copper in the aqueous sample by measuring a first change in intensity of the absorbance of the copper chelated aqueous sample; chelating the amount of zinc in the buffered aqueous sample with a zinc(II) chelating agent; and measuring the amount of zinc in the aqueous sample by measuring a second change in intensity of the absorbance of the zinc chelated aqueous sample. Other aspects are described and claimed.

A pyrogenicity test assay and method of pyrogen testing that allows for rapid and ultrahigh sensitivity testing of parenteral pharmaceuticals or medical devices that contact blood or cerebrospinal fluid by employing a Limulus Amoebocyte Lysate (LAL) assay utilizing a photonic-crystal biosensor. The photonic-crystal biosensor is capable of determining the presence of endotoxins in a test sample by monitoring shifts in the resonant wavelength of an open microcavity affected by the changes in the refractive index of the analyte solutions used.

A method for chemical identification of a sample having nanostructures includes the steps of irradiating the surface at wavelengths for each of a first and a second of the nanostructures that are uniquely absorbed by each of the first nanostructure and the second nanostructure such that each is excited to modulate at a first or a second nanostructure frequency, respectively. The method continues with the steps of irradiating the surface with electron beams incident on each of the first and second nanostructure, wherein at least one of secondary electrons, backscattered electrons and transmitted electrons are modulated at the frequency corresponding to each of the first and second nanostructure frequencies. A chemical map of the sample at an atomic scale is then created. A microscope is provided to carry out the method.