Method and compositions using transition metal salts and/or ammonium chloride to liberate toxins and other molecules from cyanobacteria, useful for assaying for total cyanobacterial toxins in lakes, reservoirs and other waters.

The present invention relates to a microfluidic method for analyzing a fluid containing a metal trace element, in particular arsenic, comprising the following steps of introducing a fluid sample into at least one micro-channel of a microfluidic circuit; mixing, within the micro-channel of the microfluidic circuit, the introduced fluid sample with nitric acid and L-cysteine, and measuring the quantity of metal trace element present in the sample, using an electrochemical detection method.

To measure target component concentration in a liquid with higher accuracy without any dedicated apparatus or skill, a method is adapted to include: receiving a successive measurement value obtained by performing successive measurement of the target component concentration with use of a first measurement device immersed in the liquid; receiving a batch measurement value obtained by, with use of a second measurement device, performing batch measurement of the target component concentration in a part sampled from the liquid; and, when the batch measurement value is received, successively calculating a correlation value indicating the correlation between multiple successive measurement values and multiple batch measurement values respectively obtained in mutually corresponding multiple times of successive measurement and multiple times of batch measurement. In addition, the first measurement device is adapted to calculate the target component concentration or correct a successive measurement value with use of the latest correlation value.

This invention discloses an improved laser induced breakdown spectroscopy (LIBS) apparatus and method for the detection of mineral and metal contamination in liquid samples. The mineral and metal contaminant is first collected by filtering the liquid sample with a membrane filter. The membrane filter with the mineral and metal contaminant is then measured by a LIBS apparatus. The LIBS apparatus is based on a high repetition rate pulsed laser. The laser produces a train of laser pulses at a high repetition rate in the kHz (or even higher) range. When the laser beam hits the surface of the membrane filter, it generates several thousands of micro-plasma emissions per second. Synchronized miniature CCD array optical spectrometer modules collect the LIBS signal from these micro-plasma emissions. By adjusting the integration time of the spectrometer to cover a plurality of periods of the laser pulse train, the spectrometer integrates the LIBS signal produced by this plurality of laser pulses. Hence the intensity of the obtained LIBS spectrum can be greatly improved to increase the signal-to-noise ratio (SNR) and lower the level of detection (LOD).

An apparatus for measuring the cation conductivity of a fluid sample includes a housing having an inlet disposed at a first end of the housing and an outlet disposed at a second end of the housing, the second end opposite the first end, wherein the inlet of the housing is configured to receive the fluid sample. The apparatus includes a first cellulose filter disposed in the housing adjacent to the inlet; a second cellulose filter disposed in the housing adjacent to the outlet; and a cation exchange resin filter disposed in the housing between the first cellulose filter and the second cellulose filter. The outlet of the housing is configured to be fluidically connected to a cation conductivity sensor configured to measure a cation conductivity of an effluent output from the outlet of the housing.

A composition includes a fluorophore, a spacer bound to the fluorophore and a receptor having an unsaturated heterocycle ring bound to the spacer. The spacer is methylamine. The receptor and/or the spacer has a receptor sidechain bound to the unsaturated heterocycle ring and/or a spacer sidechain bound to the methylamine, respectively. The composition may be employed as a chemosensor configured to capture an ion in a fluid medium. The chemosensor may further be incorporated into a sensing device configured to detect the ion and calculate a concentration of the ion in the fluid medium.

The present invention relates to a water sampling immersion probe (50) for continuously filtering a water sample from wastewater (14). The water sampling immersion probe (50) includes a distal coarse filter (60) with a porosity of 0.1 to 1.0 mm, a proximal fine filter (70) arranged downstream of the coarse filter (60) and having a porosity of less than 5.0 μm, and a sample suction opening (74) arranged downstream of the fine filter (70). The coarse filter (60) is arranged to not contact the fine filter (70).

A portable assessment kit for measuring metal content of an aqueous solution. The kit includes a sample container having an opening at its first end for containing a sample of the aqueous solution, a disc holder having a first end for detachably attaching the disc holder to the opening of the sample container, a pre-concentration disc for collecting metals and being arrangeable in the disc holder. The pre-concentration has a first side and a second side. The kit further includes means for pumping the sample through the opening of the sample container to the first side of the pre-concentration disc and a measurement device for measuring amount of metals in the pre-concentration disc.

A water quality measuring system includes a first introduction section for introducing rearing water as a sampling target, and a first adding section which adds an acid to the rearing water introduced by the first introduction section, and a nitrous acid sensor whose measurement target is nitrous acid and which measures the measurement target concentration of the rearing water to which the acid has been added by the first adding section. The water quality measuring system includes a second adding section which adds a base to the rearing water introduced by the first introduction section, and an ammonia sensor whose measurement target is ammonia and which measures the measurement target concentration of the rearing water to which the base has been added by the second adding section.

Fluorescent Schiff base compounds comprising a xanthene dye based moiety and an alkyl imidazole moiety. Methods of assessing these fluorescent Schiff base compounds as fluorescent probes for metal ions in Cu.sup.2+ chemosensing applications, methods of preparing the fluorescent Schiff base compounds and methods of detecting Cu.sup.2+ ions with the same are also provided.