• Expanded our optical line to include absorbance, turbidity and UV applications
  
• Enhanced our laboratory platform to include an easy-to-use and comprehensive user interface
  
• Developed new submersible platforms and accessories designed for long-term deployment

All of our instruments can be built for specified custom optics because we understand that research needs are not the same throughout varying environments and applications.

In this edition we'd like to highlight our new C6 Multi-Sensor Platform designed to provide intelligent interface capabilities, flexible optical sensor integration and increased power for long-term deployments. The C6 Multi-Sensor Platform design was initiated after an overwhelmingly positive response on the Cyclops-7 analog fluorometer. With increasing optical applications and the need for more flexibility we feel the C6 Multi-Sensor Platform adds excellent features such as a mechanical bio-fouling wiper and increasing benefits including a robust battery for extended deployments. We are excited to launch the new C6 Multi-Sensor Platform before the New Year!

Yours Truly,
Chelsea Donovan
Environmental Marketing Manager

Coming Soon! C6 Multi-Sensor Platform

The submersible C6 Multi-Sensor Platform was designed for extended or short-term deployments. Each C6 comes with
a factory installed temperature and pressure sensor at a
depth rating of 600 meters. The C6 Windows™ based
user interface allows for intuitive calibration, data
logging, and data management.

The submersible battery pack and dual-arm mechanical wiper allow for deployments longer than 85 days! Users can install up to six Cyclops-7 optical sensors into the C6 Multi-Sensor Platform for a variety of applications such as in vivo Chlorophyll a, freshwater blue green algae (phycocyanin), marine blue green algae (phycoerythrin), rhodamine WT dye, fluorescein dye, or turbidity. The Cyclops-7 CDOM sensor will be available soon!

New PhytoFlash Performance Data

The PhytoFlash is a solid state (patent pending) submersible active fluorometer designed to detect minimum fluorescence (Fo), maximum fluorescence (Fm), and quantum efficiency (Fv/Fm or yield) of phytoplankton. These data can be determined during extended deployments, CTD profiles, or in the laboratory. The Turner Designs submersible battery allows well over 45 days of logging at 15-minute intervals.

The PhytoFlash Submersible Active Fluorometer can be used for applications such as:

• In situ measurement of phytoplankton photosynthetic parameters
  
• Indicator of nutrient status of planktonic algae
  
• Detection of the onset of algae blooms
  
• Accurate measurement of algae biomass and monitoring algal community changes
• Measurement of non-photochemical quenching
  (laboratory mode)
• Ballast water monitoring

Yield comparisons of the diatom Thalassiosira weissflogii utilizing the fluorometric DCMU herbicide technique and the Turner Designs PhytoFlash Active Fluorometer (n=4).

Comparison of Turner Designs PhytoFlash submersible active fluorometer and the Walz's PAM benchtop fluorometer (MT) using green algae (Dunaliella) cultures at different concentrations

Comparison of Turner Designs PhytoFlash and Chelsea's Fast Tracka 1 during combined profiles in Monterey Bay

Question: When measuring the fluorescence of Chlorophyll a, can Rhodamine WT be used as a secondary standard?

Answer: Yes. Rhodamine WT is a suitable secondary standard for fluorometers that are equipped with chlorophyll a optics. The solid secondary standards that are offered by Turner Designs (see Table 1) are highly recommended because they are easy to use and deliver a stable signal. In situations where it is not possible to use the solid standard, Rhodamine WT is an excellent alternative. For customers who infrequently work with Rhodamine, an adjustable solid standard can be set to simulate a known concentration of Rhodamine WT, eliminating the need to keep liquid Rhodamine WT on hand. Exposure to sunlight has very little effect on Rhodamine WT but free chlorine will rapidly destroy Rhodamine WT dye. The maximum excitation wavelength of rhodamine WT is 558 nm and the maximum emission wavelength is 583 nm (see Figure 1).

table 1

figure 1

Rhodamine WT Dilutions and Solid Secondary Adjustment

Turner Designs offers an excellent resource page that covers the preparation of dye standards. Figure 2 illustrates the visual characteristics of Rhodamine WT.

If an adjustable solid secondary standard is available, it can be adjusted to simulate a signal generated from a specific concentration of Rhodamine WT or a specific algal sample. After the fluorometer is calibrated with a Primary standard, measure the Secondary standard. If the measurement is lower than the Primary standard, adjust the Secondary standard so that more of the fluorescent material is exposed. Conversely, if the signal is higher, decrease the amount of exposed fluorescent material. Once the solid standard has been adjusted, it can be re-measured at any time. Repeatable results will verify calibration and instrument performance.

figure 2

Trilogy Laboratory Fluorometer - New Phosphate and Silicate Absorbance Modules!

The Trilogy Laboratory Fluorometer not only has fluorescence capabilities, it can also measure turbidity and absorbance! We've recently designed two Absorbance Modules that detect inorganic Phosphate and Silicate using the standard methods adapted from Strickland and Parsons, "A Practical Handbook of Seawater Analysis". Now researchers can use wet chemistry techniques and read absorbance measurements on their Trilogy Laboratory Fluorometer!

Inorganic Nutrient Analysis Using Turner Designs Trilogy Absorbance Module
Inorganic nutrient analysis is important in determining primary production and the health of aquatic systems. Turner Designs has developed a cost efficient way for researchers to accurately estimate inorganic nutrient levels in water habitats such as rivers, lakes, coastal and open ocean environments. Turner Designs Trilogy Absorbance Modules use a combination of Light Emitting Diodes (LED's) and bandpass filters for nutrient specific wavelengths.

Phosphate Absorbance Module:
The Phosphate Absorbance Kit (P/N 7200-070) is available now. The kit includes an Absorbance Module with a phosphate-specific IR LED and filter paddle. The kit is used for measuring extinction coefficients at 885-nanometers (nm) as described by Strickland and Parsons (1968): "Determination of Reactive Phosphorus". This method involves a simple ammonium molybdate chemical reaction, which yields a blue solution. The color intensity is proportional to the concentration of phosphate in the solution. Preliminary results show good linearity down to 1-micromolar (µM) concentration of inorganic phosphate (Fig. 1). For further detail see the Turner Designs application note on inorganic Phosphate determination.

Figure 1: Calibration curve for phosphate absorbance of known standard concentrations from 1-10 µM. (Upper detection limit = 70 µM)

Figure 2: Comparison data showing samples collected from San Francisco Bay by Al Marchi at Romberg Tiburon Labs. Analyses were made using the "Determination of Reactive Phosphate method" from Strickland and Parsons (1968)

Figure 2 shows comparison data from split water samples analyzed using a Bran & Luebbe Auto Analyzer for low level determination of inorganic nutrients and a Turner Designs Trilogy with a Phosphate Absorbance Module.

Inorganic phosphate is typically limiting and one of the three necessary nutrients used for primary production by terrestrial and aquatic plants. Monitoring of phosphate levels in water can help identify possible sources for introduction to aquatic systems. Measuring phosphate in aquatic environments can be a very important tool in understanding the health of a system or its "water quality".

Silicate Absorbance Module:
Silica is an important element in animal and plant life. Specifically biogenic silica, which is simply hydrated silica, is extracted from water by plants, microorganisms, or invertebrates for use as structural material. Estimating the silica content of water systems can be very helpful in determining community structure and ecosystem dynamics. For open ocean environments, surface waters may have a stable silica concentration, increasing with depth. During upwelling events the surface water silica concentrations increase. Diatoms can take advantage of this source of silica and bloom during these events producing food for higher trophic levels.

Preliminary work on silicate determination using Turner Designs Trilogy Silicate Absorbance Module shows a strong linear relationship from 1 - 100 µM silicate, with r² value of 0.99 (Fig 2). Low concentration results show that we can detect down to 0.1 µM silicate concentration (Fig 1).

Fig 1: Silicate determination for low µM concentrations showing a strong linear relationship and good fit (r2=0.99).

Fig 2: Strong linear relationship for a broad range of silicate concentrations (1 - 100 µM).

Silicate performance testing is currently underway with Romberg Tiburon Labs. Those data will be posted to the Turner Designs Databank for customer viewing. The Silicate Absorbance Module will be released and available for purchase soon.

What?
In response for more 'real-world' data from our customers, Turner Designs has launched the TD Databank Program where we present examples of customer research for all instruments and applications. The Databank is organized according to instrument type and application and offers our users real-world examples of how researchers and technicians are using Turner Designs instruments in their work. In addition to providing meaningful information for our customers, by having a description of your work highlighted on our website, it will serve as a means of reaching a greater number of scientists around the globe. We see this as a highly effective means of assisting our users in making informed decisions. In order for this type of program to succeed, we need information from you on your application and how a Turner Designs fluorometer is helping you.

How?
We have designed the TD Databank to make submitting an application summary as easy as possible. The entire process should not take more than 20 minutes. We ask for a brief description of your research, and how you use Turner instruments. Also, a picture or graph of data collected with Turner instruments is requested. To show our appreciation for your databank articles, we will send you a Turner Designs sports bag. Claim your sports bag now by submitting your Databank article!

Why?
We hope you will join us in this exciting and useful program by sharing your knowledge and experience with scientists and technicians around the globe. To take part, please visit http://www.turnerdesigns.com/databank/submit_data.html.