Various methods, devices, and systems for determining the concentration of microorganisms in a sample and determining the susceptibility of such microorganisms to one or more antibiotics or other types of anti-infectives are disclosed herein. More specifically, methods for quantifying microorganisms based on redox reactions are disclosed along with systems and devices for quantifying such microorganisms using certain oxidation reduction potential (ORP) sensors. Moreover, methods for determining the susceptibility and the degree of susceptibility of microorganisms to one or more anti-infectives are disclosed along with multiplex systems for such assays.

The invention provides a method for determining the antioxidant capacity of beverage by titrating a standard oxidant solution using liquid sample of the beverage and monitoring oxidation reduction potential of the solution until a neutral reference value is reached, and using the titration volume to calculate the antioxidant capacity. The invention also provides test apparatus and test kit for performing the method of the invention.

This disclosure relates to an apparatus for glucose-sensing that address interference of ascorbic acid and acetaminophen. The apparatus includes a first electrode capable of oxidizing glucose and at least one of ascorbic acid and acetaminophen. The apparatus further includes a second electrode capable of oxidizing at least one of ascorbic acid and acetaminophen but not capable of oxidizing glucose. The first electrode includes a deposit of irregularly shaped bodies that are formed of numerous nanoparticles having a generally oval or spherical shape with a length ranging between about 2 nm and about 5 nm.

A method of determining a disinfectant composition of a municipal water supply from a water sample that includes: (a) obtaining a water sample from a water source at a sampling location; (b) adding a chlorine-containing material to the water sample in the presence of an oxidation reduction potential (ORP) measurement device; (c) generating a plurality of ORP measurements during addition of the chlorine-containing material to the water sample; (d) estimating a concentration of one or more of free ammonia, fully combined ammonia, monochloramine, or a mixture of dichloroamine and trichloroamine in the water sample in which the estimation is derived from the relationship between the added chlorine material and the plurality of ORP measurements; and (e) determining a disinfectant composition of the water source at the water sampling location from the concentration calculation. A method of determining free ammonia composition is also included.

A water preparation apparatus for determining an amount of total chlorine in purified water is disclosed. The water preparation apparatus includes a chlorine sensing system, a water pretreatment filter, a reverse osmosis filter, and an electrodeionization (“EDI”) module. The chlorine sensing system is configured to determine an amount of total chlorine in the purified water by applying, at a first time, a source voltage to the purified water and removing, at a second time, the source voltage. The chlorine sensing system then measures, after the second time, an electrical parameter of the purified water. The chlorine sensing system determines the amount of total chlorine in the purified water based on the measured electrical parameter.

Various devices, systems and methods of detecting a susceptibility of one or more infectious agents to one or more anti-infectives are described herein. In one embodiment, a method of detecting the susceptibility of the infectious agents to the anti-infectives involves introducing a sample comprising the infectious agents to a filter comprising a filter surface. The filter surface can be configured to capture the infectious agents in the sample. The method can also involve introducing a solution to the filter surface such that the solution is in fluid communication with the infectious agents captured on the filter surface. The solution can comprise nutrients and one or more anti-infectives. The method can further involve monitoring an oxidation reduction potential (ORP) of the solution using one or more parameter analyzers coupled to a sensor currently in fluid communication with the solution to assess the susceptibility of the infectious agents to the anti-infectives.

A method for relative quantification of organic and biological compounds by electrochemical mass spectrometry is disclosed. The method involves using electrochemistry (EC) in a mass spectrometry (MS)-based relative quantitative analysis. In this method, isotope-labeled standards or running calibration curves are not employed. A quantification method could include the steps of subjecting a sample analyte to liquid chromatography or electrophoresis separation, followed by an electrochemical oxidation or reduction in an electrochemical cell, and then mass spectrometric detection.

Electrochemical probes (or sensors), resistant to corrosive agents present in seawaters or in industrial waters, useful for detecting compounds present in water, are here described, wherein said probes comprise at least one polymer matrix electrode, in which said electrode is selected from the group comprising counter electrode, reference electrode and working electrode.

Various devices, systems and methods of detecting a susceptibility of one or more infectious agents to one or more anti-infectives are described herein. In one embodiment, a method of detecting the susceptibility of the infectious agents to the anti-infectives involves introducing a sample comprising the infectious agents to a filter comprising a filter surface. The filter surface can be configured to capture the infectious agents in the sample. The method can also involve introducing a solution to the filter surface such that the solution is in fluid communication with the infectious agents captured on the filter surface. The solution can comprise nutrients and one or more anti-infectives. The method can further involve monitoring an oxidation reduction potential (ORP) of the solution using one or more parameter analyzers coupled to a sensor currently in fluid communication with the solution to assess the susceptibility of the infectious agents to the anti-infectives.

A method of determining a disinfectant composition of a municipal water supply from a water sample that includes: (a) obtaining a water sample from a water source at a sampling location; (b) adding a chlorine-containing material to the water sample in the presence of an oxidation reduction potential (ORP) measurement device; (c) generating a plurality of ORP measurements during addition of the chlorine-containing material to the water sample; (d) estimating a concentration of one or more of free ammonia, fully combined ammonia, monochloramine, or a mixture of dichloramine and trichloramine in the water sample in which the estimation is derived from the relationship between the added chlorine material and the plurality of ORP measurements; and (e) determining a disinfectant composition of the water source at the water sampling location from the concentration calculation. A method of determining free ammonia composition is also included.