Bioluminescence detector

Bioluminescence detector Charge-coupled device Contactless-conductivity detector Capillary electrophoresis Capillary electrophoresis-Electrochemistry Collision-induced dissociation Chemiluminescence detector Sodium chlorate-nitrobenzene Commercial off-the-shelf (U.S. Army) Cold Regions Research and Development Center Croatian Mine Action Center Council of Scientific and Industrial Research,... 

Because bioluminescence in marine surface waters (upper 100 m) is primarily due to small plankton, it can he successfully characterized by relatively simple photometer systems. The two basic types of bioluminescence detectors are an open type that views directly out into the seawater and a closed type that views a closed volume through which seawater is pumped. The bioluminescence variability is an interdependent phenomenon often associated with changes in physical and chemical parameters. For example, ocean frontal regions are almost always associated with enhanced levels of bioluminescence. Bioluminescence spectral content and signal kinetics often indicate the type of organisms present. 

Our primary measurement technique was to pull seawater through a 25-mL volume chamber with a pump. The organisms emit light when stimulated by the tur-bulently flowing seawater. This light is viewed by a photomultiplier tube (PMT). Two in situ measurement systems were used on surface ships. The on-board bioluminescence detector pulls seawater from below the ship s hull for continuous realtime measurements of surface bioluminescence a bathyphotometer was used on station to depths of 100 m. An additional laboratory system was used to measure bioluminescence flashes from individual plankters isolated from plankton tows and pumped collections. 

Figure 1. On-board bioluminescence detector used for surface measurements. (Reproduced with permission from Ref. 7.)...

Other Parameters Measured Simultaneously with Bioluminescence. Measurements of several other parameters were obtained from the seawater after it had traversed the bioluminescence detector. When working on station with the bathy-photometer, which was equipped with a pressure transducer, temperature and beam transmittance were measured at depth while seawater was pumped by the submersible pump at depth to shipboard with 110 m of 2.54-cm ID hose. Sea surface temperature was obtained continuously from a probe at the intake near the sea chest. The seawater, obtained from either the sea chest or the bathyphotometer, was pumped through a Turner Designs fluorometer to measure chlorophyll fluorescence, and past a pH probe (31) and a conductivity cell when available. Samples of seawater were frozen for subsequent nutrient analysis (NO , NH4OH, P04 , and NO2). Plankton filtrates from 20 to 100 L (depending on plankton abundance) of seawater were collected from a 100-L effluent tank fitted with plankton net collection cups of 20-fxm mesh porosity. The filtrate was split, filtered onto Whatman GF/C 4.25-cm filter discs, and frozen for subsequent carbon and nitrogen determinations. The other half of the sample was preserved in 5% buffered formaldehyde solution for taxonomic analysis. 

Figure 1, Top High time-resolution data [scan, multichannel scaling (MCS) mode] recorded by the on-hoard bioluminescence detector in the Gulf of Alaska. The signal intensity has been attenuated with a neutral-density 3 filter (1000 X attenuation) inserted between the viewing chamber window and face of the photocathode of the PMT.

Figure 8. High time-resolution data (scan, MCS mode) recorded by the onboard bioluminescence detector in both the broad-band and UV portions of the bioluminescence spectrum from the Gulf of California. The signal is produced mainly by luminous zooplankton.

The chemiluminescence and bioluminescence detectors have much to benefit from FI techniques. Chemiluminescence and bioluminescence reactions are often rapid, and the duration of the signals extremely short therefore only the signals from slower reactions can be reproducibly monitored by batch procedures, whereas reactions in the millisecond range may be readily monitored in an FI system. Such detectors are often constructed in a spiral form to increase the light flux. 

With the newly proposed detector, Dadoo et al. [84] adapted this bioluminescence reaction to determine ATP. A selective and sensitive determination is achieved because the use of CE as a separation technique minimizes the effect of several interfering substances such as some anions (e.g., SCN, I ) that inhibit the reaction decreasing the luminescence emission, and even some nucleotides that generate light in this reaction but with lower intensity. A detection limit of 5 nM, approximately 3 orders of magnitude lower than using UV detection, was obtained. 

The instrumentation used to measure in situ marine bioluminescence fits into three basic categories. These categories include, first, a closed system in which seawater is pulled into a light-tight volume viewed by a detector (usually a photomultiplier tube) (7,10-12) that measures bioluminescence stimulated by the turbulently flowing seawater. Second, open detectors view directly out into the seawater (3, 6) and measure stimulated... 

Luminescence molecular detectors have also been used for on-line monitoring of dissolution tests and the characterization of toxic residues using bioluminescence assays [28]. 

It has been almost seven years since the publication of the first English Edition of my book on TEC The following improvements in technology over the years have made it necessary for me to update the first edition new precoated layers for both existing and new fields of applications, a new generation of equipment for safe operations and reproducible results, new devices such as the Diode Array Detector and Bioluminescence Analyzer, new methods of interface between TEC and analysis methods, especially the use of digital cameras for the documentation of thin layer chromatograms. For the reader s benefit, I have updated my description of available products on the market. 

Bioluminescence was measured by a chemi-luminescence detector or our newly developed onsite monitoring system using a digital camera. The data were transferred to a (mobile) PC machine with a snaart media card device. Luminescent intensity was numerated by black and white scale using Scionimage soft. 

This monograph covers the different modes of flow analysis, as well as more generic aspects, including applications relying on spectrophotometry. Emphasis is given to flow-through detectors based on attenuation of radiation (spectrophotometry and turbidimetry) or radiation emission (fluo-rimetry, chemiluminescence and bioluminescence) by a flowing sample. 

The approach is very useful for e.g., chemi- and bioluminescence detection when the monitoring of short-lived chemical species is done as close as possible to the detector. With pulsed flows, mixing conditions are no longer a weakness [125] because manifold simplicity and very fast and effective mixing of the sample with reagent(s) are characteristics of multipumping flow systems. 

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