Comparative Studies on Effects of Acid Solutions on Aquatic Plants by Beam Deflection and Absorbance Spectroscopy...

Area of Science:

• Environmental Science
• Plant Biology
• Analytical Chemistry

Background:

• Aquatic plants play a crucial role in freshwater ecosystems.
• Understanding plant responses to environmental changes, such as pH variations, is vital.
• Traditional methods for assessing plant stress may have limitations.

Purpose of the Study:

• To compare the efficacy of beam deflection and absorbance spectroscopy in studying the effects of acid solutions on aquatic plants.
• To investigate the sensitivity and response time of each method.
• To identify potential compounds released by plants into acidic solutions.

Main Methods:

• Utilized Egeria densa and Ceratophyllum demersum L. as model aquatic plants.
• Employed absorbance spectroscopy to measure solution absorbance over time.
• Applied the beam deflection method using a He-Ne laser and position sensor to monitor plant-induced beam deflection.

Main Results:

• Absorbance spectroscopy detected compounds leaching from plants into HCl solutions below 410 nm.
• Both methods showed similar trends but absorbance measurements were delayed by 2-3 hours.
• Beam deflection successfully detected effects at pH 5.0, where absorbance spectroscopy showed no significant changes.

Conclusions:

• Beam deflection offers higher sensitivity and faster response for detecting aquatic plant stress in acidic conditions compared to absorbance spectroscopy.
• The release of compounds from plants into acidic solutions is confirmed by absorbance changes.
• Beam deflection is a promising technique for early-stage environmental stress monitoring in aquatic plants.