Abstract: Disclosed is a real-time method for detecting copper and silver in water in parts per billion. Total silver is detected by adding a nitric acid solution to the sample; after the silver is digested, adding a buffer solution comprising water, sodium bicarbonate, sodium carbonate and EDTA to the sample; adding an indicator comprising Cadion 2B, EtOH, and Triton X-100 to the sample; then reading the absorbance of the sample after light with an approximate target peak of 515 nm is sent through the sample; and determining the silver concentration by comparing the absorbance of the sample to the absorbances of known silver standards.

Abstract: A method of testing the composition or quality of water includes dissolving about two parts by weight of a 2-hydroxybenzyl alcohol and about one part by weight of a sodium nitroprusside in about seventy-five parts by weight of a polyethylene glycol; adding the sodium nitroprusside solution to a water sample to catalyze an indophenol monochloramine reaction; and detecting the concentration of monochloramine in the water sample. The polyethylene glycol may be a polyethylene glycol 300, a PEG-400 or a PEG-1000. The method may also be accomplished with a solution made by dissolving a 2-hydroxybenzyl alcohol and a sodium nitroprusside in a mixture of propane-1,2-diol and water.

Abstract: Stabilized indicator compositions, and systems and methods using the same are described. In embodiments the stabilized indicator compositions include a solvent, an indicator, a stabilizer for the indicator, and optionally a buffer. In embodiments the indicator is or includes N, N-diethyl-p-phenylene diamine (DPD). Systems and methods utilizing the stabilized indicator composition to determine an amount of at least one constituent in a test sample (e.g., water) are also described. In embodiments, the systems and methods remove the stabilizer from the stabilized indicator composition to produce a fluid flow containing un stabilized indicator, which is then combined with a fluid from a sample source to form a test sample for analysis.

Abstract: Disclosed is a real-time method for detecting copper and silver in water in parts per billion. Total silver is detected by adding a nitric acid solution to the sample; after the silver is digested, adding a buffer solution comprising water, sodium bicarbonate, sodium carbonate and EDTA to the sample; adding an indicator comprising Cadion 2B, EtOH, and Triton X-100 to the sample; then reading the absorbance of the sample after light with an approximate target peak of 515 nm is sent through the sample; and determining the silver concentration by comparing the absorbance of the sample to the absorbances of known silver standards.

Abstract: Disclosed is a real-time method for detecting copper and silver in water in parts per billion. Total silver is detected by adding a 2% nitric acid solution to the sample; after ten minutes, adding a buffer solution comprising water, sodium bicarbonate, sodium carbonate and EDTA to the sample; adding an indicator comprising Cadion 2B, EtOH, and Triton X-100 to the sample; after one minute, reading the absorbance of the sample using a spectrophotometer with a target peak of 515 nm; and determining the silver concentration by comparing the absorbance of the sample to the absorbances of known silver standards.

Abstract: A method of testing the composition or quality of water includes dissolving about two parts by weight of a 2-hydroxybenzyl alcohol and about one part by weight of a sodium nitroprusside in about seventy-five parts by weight of a polyethylene glycol; adding the sodium nitroprusside solution to a water sample to catalyze an indophenol monochloramine reaction; and detecting the concentration of monochloramine in the water sample. The polyethylene glycol may be a polyethylene glycol 300, a PEG-400 or a PEG-1000. The method may also be accomplished with a solution made by dissolving a 2-hydroxybenzyl alcohol and a sodium nitroprusside in a mixture of propane-1,2-diol and water.

Abstract: A method to extend a shelf life of a sodium nitroprusside solution includes: dissolving about two parts by weight of a 2-hydroxybenzyl alcohol and about one part by weight of a sodium nitroprusside in about seventy-five parts by weight of a polyethylene glycol. Compositions for preserving a sodium nitroprusside solution are also described.

Abstract: A water hardness mitigation or treatment evaluation system includes a first quartz crystal microbalance cell and a fluid coupling adapted to be fluidly coupled to a pre-treated water to be flowed over a first quartz crystal. A second quartz crystal microbalance cell and a fluid coupling are adapted to be fluidly coupled to a post-treated water to be flowed over a second quartz crystal. A computer processor receives a first frequency data from the first quartz crystal and a second frequency data from the second quartz crystal and based on a difference of frequency over time between the first frequency data and the second frequency data, provides an indication of an effectiveness of a water hardness mitigation or treatment component or system. A method to evaluate and effectiveness of a water hardness mitigation or treatment evaluation system is also described.

Abstract: A method to extend a shelf life of a sodium nitroprusside solution includes: dissolving about two parts by weight of a 2-hydroxybenzyl alcohol and about one part by weight of a sodium nitroprusside in about seventy-five parts by weight of a polyethylene glycol. Compositions for preserving a sodium nitroprusside solution are also described.

Abstract: A spectrophotometer includes an electronics compartment having disposed within, at least one light source, and at least one optical detector. A testing compartment has disposed within, an optical block having at least one fluid connection port, and a first light pipe optically coupled between the at least one light source and the optical block. A second light pipe is optically coupled between the optical block and the at least one optical detector. The testing compartment is adapted to perform spectrophotometry of a fluid sample disposed within a sample container in the optical block, and the electronics compartment is electrically isolated from the testing compartment. A spectrophotometer for use in an explosive atmosphere and a method of measuring a presence or concentration of an organic or inorganic compound in a fluid in an explosive atmosphere are also described.

Abstract: A spectrophotometer includes an electronics compartment having disposed within, at least one light source, and at least one optical detector. A testing compartment has disposed within, an optical block having at least one fluid connection port, and a first light pipe optically coupled between the at least one light source and the optical block. A second light pipe is optically coupled between the optical block and the at least one optical detector. The testing compartment is adapted to perform spectrophotometry of a fluid sample disposed within a sample container in the optical block, and the electronics compartment is electrically isolated from the testing compartment. A spectrophotometer for use in an explosive atmosphere and a method of measuring a presence or concentration of an organic or inorganic compound in a fluid in an explosive atmosphere are also described.

Abstract: A water hardness mitigation or treatment evaluation system includes a first quartz crystal microbalance cell and a fluid coupling adapted to be fluidly coupled to a pre-treated water to be flowed over a first quartz crystal. A second quartz crystal microbalance cell and a fluid coupling are adapted to be fluidly coupled to a post-treated water to be flowed over a second quartz crystal. A computer processor receives a first frequency data from the first quartz crystal and a second frequency data from the second quartz crystal and based on a difference of frequency over time between the first frequency data and the second frequency data, provides an indication of an effectiveness of a water hardness mitigation or treatment component or system. A method to evaluate and effectiveness of a water hardness mitigation or treatment evaluation system is also described.