Methods and apparatus for determination of halohydrocarbons
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.
1. An apparatus to monitor halohydrocarbon presence in a water distribution system, the apparatus comprising:
circuitry to communicate with a network;
a sample extraction mechanism to from-time-to-time draw water samples from the water distribution system;
a reservoir for a standard;
a measurement system to obtain measurements of halohydrocarbon concentration in respective ones of the water samples;
an electronic control system to
control the sample extraction mechanism and the measurement system so as obtain the measurements,
control the apparatus so as to from-time-to-time perform calibrations using the standard, and
renew the measurement system for ensuing ones of the measurements;
wherein the electronic control system is to control the apparatus to obtain the measurements according to timing that is externally dictated via the network.
2. The apparatus of claim 1 , wherein the circuitry is to connect to a wide area network (WAN), wherein the electronic control system is to receive instruction from the WAN to dynamically draw a water sample from the water distribution system and to measure halohydrocarbon concentration in the dynamically-drawn water sample, and wherein the apparatus is further to transmit via the WAN at least one result dependent on measurement of halohydrocarbon concentration in the dynamically-drawn water sample.
3. The apparatus of claim 1 , wherein the circuitry is to connect to a wide area network (WAN), wherein the electronic control system is to receive instruction from the WAN to dynamically calibrate the measurement system, and wherein the apparatus is further to transmit via the WAN at least one result dependent on the dynamic calibration of the measurement system.
4. The apparatus of claim 1 , wherein:
the measurement system comprises an adsorption medium;
the measurement system is to transfer controlled volumes of water from the samples to the adsorption medium to separate halohydrocarbons from the controlled volumes of water and is to combine the separated halohydrocarbons with one or more reagents to cause color development in a manner dependent on amount of the separated halohydrocarbons; and
a chromatograph to generate measurements of halohydrocarbon concentrations in the controlled volumes of water according to developed color.
5. The apparatus of claim 4 , wherein the reservoir is a first reservoir, wherein the apparatus comprises a second reservoir, wherein the one or more reagents comprise a pyridine derivative, and wherein the measurement system is to transfer pyridine derivative from the second reservoir to as to combine the separated halohydrocarbons with the pyridine derivative.
6. The apparatus of claim 4 , wherein the one or more reagents comprise a pyridine derivative characterized by a pyridine structure with one or more substitutions of hydrogen at the carbon atoms of the pyridine.
7. The apparatus of claim 4 , wherein the measurement system is to for at least one of the water samples perform plural, time-separated measurements of developed color and wherein the apparatus is to calculate concentrations from the time-separated measurements respective to at least two different halohydrocarbon species.
8. The apparatus of claim 1 , wherein the measurement system is to for at least one of the water samples perform plural measurements and wherein the apparatus is to calculate concentrations from the plural measurements respective to at least two different halohydrocarbon species.
9. The apparatus of claim 1 , further comprising digital memory, wherein the electronic control system is to store in the digital memory results of each of the measurements including, for each one of the measurements, at least a time that the one of the measurements was performed and a measure of halohydrocarbon concentration detected by the one of the measurements.
10. The apparatus of claim 1 , wherein the electronic control system is transmit to the network results of each one of the measurements including at least, for each one of the measurements, a time that the one of the measurements was performed, a measure of halohydrocarbon concentration detected by the one of the measurements, and at least one of a location or an identification of the apparatus.
11. The apparatus of claim 1 , wherein the electronic control system is to control the apparatus such that at least one of the calibrations is performed as a spike test, on the basis of both of the standard and one of the samples.
12. The apparatus of claim 1 , wherein the standard comprises a predetermined concentration of halohydrocarbons.
13. The apparatus of claim 1 , wherein the standard comprises at least one of CHCl 3 , CHBrCl 2 , CHBr 2 Cl and CHBr 3 .
14. An apparatus to monitor halohydrocarbon presence in a water distribution system, the apparatus comprising:
circuitry to communicate with a network;
a sample extraction mechanism to from-time-to-time draw water samples from the water distribution system;
a first reservoir for a standard and a second reservoir for a reagent;
a measurement system to obtain measurements of halohydrocarbon concentration in respective ones of the water samples, wherein the measurement system is to measure halohydrocarbon concentration by creating a reaction between halohydrocarbons separated from the samples and the reagent and by measuring an optical property of the reaction;
an electronic control system to
control the sample extraction mechanism and the measurement system so as obtain the measurements,
control the apparatus so as to from-time-to-time perform calibrations using the standard, and
renew the measurement system for ensuing ones of the measurements;
wherein the electronic control system is to control the apparatus so as to obtain the measurements according to timing that is externally dictated via the network.
15. The apparatus of claim 14 , wherein the reagent comprises a pyridine derivative and wherein the measurement system is to transfer pyridine derivative from the second reservoir so as to combine the separated halohydrocarbons with the reagent.
16. The apparatus of claim 14 , wherein the reagent is a pyridine derivative characterized by a pyridine structure with one or more substitutions of hydrogen at the carbon atoms of the pyridine.
17. The apparatus of claim 14 , wherein the circuitry is to connect to a wide area network (WAN), wherein the electronic control system is to receive instruction from the WAN to dynamically draw a water sample from the water distribution system and to measure halohydrocarbon concentration in the dynamically-drawn water sample, and wherein the apparatus is further to transmit via the WAN at least one result dependent on measurement of halohydrocarbon concentration in the dynamically-drawn water sample.
18. The apparatus of claim 14 , wherein the measurement system is to for at least one of the water samples perform plural, time-separated measurements and wherein the apparatus is to calculate concentrations from the plural, time-separated measurements respective to at least two different halohydrocarbons species.
19. The apparatus of claim 14 , wherein the sample extraction system is to connect in-line to a distribution element of the water distribution system to draw the water samples therefrom.
20. The apparatus of claim 14 , wherein the electronic control system is to control the apparatus such that at least one of the calibrations is performed as a spike test, on the basis of both of the standard and one of the samples.
21. The apparatus of claim 14 , wherein the at least one standard comprises at least one of CHCl 3 , CHBrCl 2 , CHBr 2 Cl and CHBr 3 .
22. An apparatus to monitor halohydrocarbon presence in a water distribution system, the apparatus comprising:
circuitry to communicate with a server via Internet;
a sample extraction mechanism to from-time-to-time draw water samples from the water distribution system;
a first reservoir for a standard and a second reservoir for a reagent;
a measurement system to obtain measurements of halohydrocarbon concentration in respective ones of the water samples, wherein the measurement system is to measure halohydrocarbon concentration by creating a reaction between halohydrocarbons separated from the samples and the reagent and by measuring an optical property of the reaction;
an electronic control system to
control the sample extraction mechanism and the measurement system so as obtain the measurements,
control the apparatus so as to from-time-to-time perform calibrations using the standard, and
renew the measurement system for ensuing ones of the measurements;
wherein the electronic control system is to control the apparatus so as to obtain the measurements according to timing that is externally dictated via the network.
23. The apparatus of claim 22 , wherein the electronic control system is to receive instruction from the server to dynamically draw a water sample from the water distribution system and to measure halohydrocarbon concentration in the dynamically-drawn water sample, and is further to provide to the server at least one result dependent on measurement of halohydrocarbon concentration in the dynamically-drawn water sample, and wherein the electronic control system is to receive instruction from the server to dynamically perform a calibration dependent on the standard and to is further to provide to the server at least one result dependent on the dynamically-performed calibration.