An automated dispersive liquid-liquid microextraction method of detecting and quanta N-nitrosamines in an aqueous sample. The method includes (a) extracting an aqueous solution containing the N-nitrosamines by mixing an extraction solvent and a dispersive solvent with the aqueous solution, such that the N-nitrosamines, or a portion thereof, re-distribute from the aqueous solution to the extraction solvent, (b) permitting the resulting mixture in (a) to form a two-phase mixture containing an aqueous phase comprising containing the aqueous solution with reduced amounts of the N-nitrosamines and an organic phase containing the extraction solvent with the N-nitrosamines extracted from the aqueous solution, (c) injecting the organic phase, or a portion thereof, into an injection port of a gas chromatograph coupled with at least one mass spectrometer, and (d) analyzing the N-nitrosamines by gas chromatography and mass spectrometry to detect and quantify the concentration of the N-nitrosamines in the aqueous solution.

The present application provides an apparatus and method of determining water filming amine concentration, which includes performing a measuring cycle and a cleaning cycle. The measuring cycle includes providing sample water to a sample water measuring container, providing, to the sample water measuring container, one or more reaction chemicals which generate color in the sample water, emitting light, via a light emitter, at a wavelength range and intensity range, through the sample water having the generated color, to a light receiver, receiving an indication of a light intensity of the light emitted through the sample water and determining a filming amine concentration of the sample water based on the light intensity. The cleaning cycle includes providing a cleaning reagent to remove amines from the sample water measuring container.

An optical sensor may be used to measure the concentration of calcium in a water sample, such as a water sample obtained from industrial process water system like a cooling tower system, a boiler water system, or a waste water system. To measure the concentration of calcium, an indicator or reagent may be added to the water sample to form a complex that absorbs light. The absorbance profile of the complex may be non-linear over a range of calcium concentrations. However, the absorbance profile can be linearized to provide calibration coefficients that are subsequently used to determine the concentration of calcium in samples having unknown calcium concentrations. The linearization of the absorbance profile can allow the optical sensor to be calibrated using two solutions. This can reduce the complexity and cost of calibrating the optical sensor, which may otherwise require at least three calibration solutions to capture the non-linear profile of the absorbance curve.

The present invention provides a system and a method for rapid quantification of bacteria in high-quality water using fluorescence spectra measurements and machine- learning. The invention is applicable to drinking water distribution systems, water purification plants, food and beverage industry, and pharma and medical industry.

The present disclosure relates to a method for microscopic examination of phytoplankton. The present disclosure solves the problem of decreased counting accuracy of perioptometry in a dry environment. The method is as follows: step 1, making an analyte into a glass slide, performing qualitative identification of the phytoplankton in the field of view; and step 2, drying the glass slide; after drying, counting the phytoplankton and full-slide rare algae on the glass slide microscopically. When the humidity of microscopy room is only 20%, the method of the present disclosure may count a sample accurately, which has a significant increase in counting accuracy compared with the existing perioptometry. The method of the present disclosure effectively solves the problem of failure to perform the perioptometry accurately due to dry ambient humidity.

A method of providing a dispense purified water stream from a water purification apparatus involving passing a water inlet stream through a first water purification station to provide a first internal purified water stream, passing the first internal purified water stream to an internal reservoir, and providing a second internal purified water stream from the reservoir, passing the second internal purified water stream into a recirculation loop, measuring the conductivity of the second internal purified water stream; passing the second internal purified water stream to a second water purification station to provide a third internal purified water stream passing the recirculated water return stream into the internal reservoir; calculating the purity of the first internal purified water stream using the measurement of the conductivity of the second internal purified water stream.

The present application relates to the technical field of water quality monitoring for water supply systems, and provides a water quality monitoring method for a water supply system, a water supply system, and a refrigeration apparatus. The water quality monitoring method for a water supply system includes: controlling to convey water to a water outlet pipe of the water supply system; obtaining a water quality parameter in the water outlet pipe; judging whether the water quality parameter meets a standard; if the water quality parameter meets the standard, ending the monitoring; if the water quality parameter does not meet the standard, proceeding to a next operation; controlling to drain the water in the water supply system; and repeating the above obtaining operation, judging operation, and draining operation, until the water quality parameter meets the standard. Through this method, the water quality parameter in the water outlet pipe may be monitored in real time, and it is controlled to drain the water in the water supply system when the water quality parameter exceeds the standard, thereby avoiding the breeding and deposition of organic matter. Moreover, this method may avoid drainage and flushing of the water supply system after a long period of inactivity, reduce operational difficulties and improve user convenience.

Oxy-pyrohydrolysis articles, systems and methods for total halogen, in particular fluorine analysis are provided. A sample containing halogen elements is provided into a pyrotube for combustion. A combustion-enhancing bed including ceramic fibers or fabrics is disposed inside the pyrotube to enhance the combustion and protect the pyrotube from damage by corrosive gases.

A method and system for injecting an unconcentrated sample into a receiving LC/MS/MS system that is configured to determine a concentration of one or more PFAS analytes within the unconcentrated sample, wherein the LC/MS/MS includes ESI. The unconcentrated sample is subjected to the following ESI conditions: i) a probe gas temperature of approximately 120° C. to approximately 180° C.; ii) a sheath gas heater setting of approximately 250° C. to approximately 400° C.; and iii) a sheath gas flow of approximately 8 L/min to approximately 12 L/min. The unconcentrated sample's concentration and/or an injected amount of the one or more PFAS analytes is determined.

A method is disclosed comprising determining a concentration of one or more compounds of a fluid in an industrial water operation in real time. The determining of the concentration of the one or more components comprises contacting an array of sensors of a microelectromechanical system (MEMS) device with a sample of the fluid to provide a sample response indicative of the concentration of the one or more components. The method further provides adjusting or maintaining at least one operating parameter of the industrial water operation based on the concentration of the one or more components of the fluid.