A real-time, on-line method and analytical system for determining halohydrocarbons in water which operate by (1) extracting on-line samples; (2) purging volatile halohydrocarbons from the water (e.g., with air or nitrogen); (3) carrying the purge gas containing the analytes of interest over a porous surface where the analytes are adsorbed; (4) recovering the analytes from the porous surface with heat (thermal desorption) or solvent (solvent elution) to drive the analytes into an organic chemical mixture; (5) generating an optical change (e.g., color change) in dependence upon a reaction involving the analytes and a pyridine derivative; and (6) measuring optical characteristics associated with the reaction to quantify the volatile halogenated hydrocarbon concentration.

Methods and apparatus are disclosed for an improved water chemistry test. Features disclosed include, without limitation, a test block, colored liquid reagents, and color comparison displays, with test chambers/vials that are generally horizontal. The mouth at the top of each vial is formed along a substantial portion of the vial's horizontal length. The vial's horizontal dimensions enable water to move throughout each vial so that a wave or waves roll from one side of the vial to the other and quickly/thoroughly mixes colored liquid reagents with sample water. At least one ridge, wall, semipermeable barrier, etc. within the vial causes water and chemical reagents to more quickly and thoroughly when the test block is agitated. At least one drain hole is positioned in a wall/side of each vial, with its bottom edge located at the fill level necessary to conduct the water sample. A valve or valves enables a user to easily drain sample water from the vial down to the proper test level. An additional element at or near the top of at least one side of each vial serves to deflect the wave(s) of water and prevent them from splashing out of the vial through the vial's mouth. Adjacent to each vial is a color comparison display. The test block base allows it to be freestanding.

Disclosed herein are host or receptor compounds that bind targets of interest. In one embodiment the compounds bind ions, such as metal ions. A compound, or a protonate or salt thereof, having the formula of: ##STR00001## Formula IIa wherein R.sup.6 is an aminoalkoxy, alkylamino, nitro or NH.sub.2; n is 1 or 2; each R.sup.2 is independently selected from an optionally substituted alkyl, halogen, optionally substituted alkoxy, optionally substituted carboxyl, or amide; a is 0 to 4.

A system and method for determining a concentration of total chlorine in dialysis water are provided. The system comprises a main unit housing a KI/water sample chamber and a sodium sulfate chamber. A first electrode pair bridges the two chambers and generates tri-iodide proportional to the amount of total chlorine in the water sample. A second electrode pair in contact with fluid in the KI/water sample detects an amount of tri-iodide generated by the first electrode pair. The system is suitable for use in connection with, or for incorporation into, a water purification system for generating dialysis fluid, and may include a display that alerts the user to stop or prevent a hemodialysis treatment if the total chlorine level exceeds a predetermined level.

A real-time method and analytical system for determining haloacetic acids in water which operate by: (1) extracting samples on ion-exchange absorbent medium; (2) concentrating haloacetic acids on hyper-crosslinked medium; (3) eluting the analytes from the concentration medium for injection into an HPLC system; (4) separating individual haloacetic acid in reverse-phase chromatography performed by the HPLC system; and (5) measuring optical characteristics (UV-absorbance) of haloacetic acids, to determine concentration. The entire process can be performed using a completely self-contained, in-situ mechanism that sits at a water distribution point for 24/7 testing, with automated control, monitoring, reporting, and employment of remedial measures (e.g., automated adjustment of the water treatment process).

Methods and apparatus are disclosed for an improved water chemistry test. Features disclosed include, without limitation, a test block, colored liquid reagents, and color comparison displays, with test chambers/vials that are generally horizontal. The mouth at the top of each vial is formed along a substantial portion of the vial's horizontal length. The vial's horizontal dimensions enable water to move throughout each vial so that a wave or waves roll from one side of the vial to the other and quickly/thoroughly mixes colored liquid reagents with sample water. At least one ridge, wall, semipermeable barrier, etc. within the vial causes water and chemical reagents to more quickly and thoroughly when the test block is agitated. At least one drain hole is positioned in a wall/side of each vial, with its bottom edge located at the fill level necessary to conduct the water sample. A valve or valves enables a user to easily drain sample water from the vial down to the proper test level. An additional element at or near the top of at least one side of each vial serves to deflect the wave(s) of water and prevent them from splashing out of the vial through the vial's mouth. Adjacent to each vial is a color comparison display. The test block base allows it to be freestanding.

Multi-parameter water analysis system with a water parameter sensing device configured to wirelessly provide detector data and a smart phone displayable indicator of water analysis test results that are calculated by an analysis application that is updateable via a cloud-based data resource to account for a manufacturing change in indicator chemistry and/or an improvement in test result display. The water parameter sensing device includes an optical sensing apparatus configured to detect light from each of a plurality of indicators for different parameters when the indicator and a chemical parameter are exposed to each other, a processor to process information of the detected light, and wireless communication circuitry for communicating detector data based on the information about the detected light to a remote device. Social networking of water quality data allows sharing to other users.

An embodiment provides a method for deriving an amount of PFAS substances from a total organic fluoride measurement in a sample, including: removing inorganic fluoride from the sample using one or more of an ion exchange cartridge and an exclusion apparatus; preconcentrating, using a solid phase extraction, at least one PFAS substance in the sample; digesting, using a working electrode and a counter electrode, the at least one PFAS substance to an amount of total organic fluoride; and determining, using an analyzer, the amount of total organic fluoride in the sample. Other aspects are described and claimed.

A measuring method of bromate ion concentration includes a first fluorescence intensity measuring process including a process of passing hydrochloric acid through an anion exchanger to elute bromate ions adsorbed to the anion exchanger into the hydrochloric acid and a process of measuring the fluorescence intensity of the hydrochloric acid passed through the anion exchanger, a second fluorescence intensity measuring process including a process of passing a hydrochloric acid solution containing a fluorescent substance whose fluorescence intensity changes due to coexistence of bromate ions through an anion exchanger to elute bromate ions adsorbed to the anion exchanger into the hydrochloric acid solution and a process of measuring the fluorescence intensity of the hydrochloric acid solution passed through the anion exchanger, and a calculation process determining the bromate ion concentration in the water sample by using the difference between the fluorescence intensities of the hydrochloric acid solution and the hydrochloric acid.

An embodiment provides a method for measuring total chlorine in a solution, including: preparing a thiocarbamate indicator; introducing the thiocarbamate indicator to a solution, wherein the solution contains an amount of monochloramine; adding an additive to the solution, wherein the additive accelerates the reaction rate between the thiocarbamate indicator and monochloramine and causes a change in fluorescence of the solution; and measuring the amount of monochloramine in the solution by measuring an intensity of the fluorescence. Other aspects are described and claimed.