TY - JOUR
T1 - Measuring Protons with Photons
T2 - A Hand-Held, Spectrophotometric pH Analyzer for Ocean Acidification Research, Community Science and Education
AU - Pardis, William
AU - Grabb, Kalina C.
AU - DeGrandpre, Michael D.
AU - Spaulding, Reggie
AU - Beck, James
AU - Pfeifer, Jonathan A.
AU - Long, David M.
PY - 2022/10/18
Y1 - 2022/10/18
N2 - Ocean Acidification (OA) is negatively affecting the physiological processes of marine organisms, altering biogeochemical cycles, and changing chemical equilibria throughout the world's oceans. It is difficult to measure pH broadly, in large part because accurate pH measurement technology is expensive, bulky, and requires technical training. Here, we present the development and evaluation of a hand-held, affordable, field-durable, and easy-to-use pH instrument, named the pHyter, which is controlled through a smartphone app. We determine the accuracy of pH measurements using the pHyter by comparison with benchtop spectrophotometric seawater pH measurements, measurement of a certified pH standard, and comparison with a proven in situ instrument, the iSAMI-pH. These results show a pHyter pH measurement accuracy of ±0.046 pH or better, which is on par with interlaboratory seawater pH measurement comparison experiments. We also demonstrate the pHyter's ability to conduct both temporal and spatial studies of coastal ecosystems by presenting data from a coral reef and a bay, in which the pHyter was used from a kayak. These studies showcase the instrument's portability, applicability, and potential to be used for community science, STEM education, and outreach, with the goal of empowering people around the world to measure pH in their own backyards.
AB - Ocean Acidification (OA) is negatively affecting the physiological processes of marine organisms, altering biogeochemical cycles, and changing chemical equilibria throughout the world's oceans. It is difficult to measure pH broadly, in large part because accurate pH measurement technology is expensive, bulky, and requires technical training. Here, we present the development and evaluation of a hand-held, affordable, field-durable, and easy-to-use pH instrument, named the pHyter, which is controlled through a smartphone app. We determine the accuracy of pH measurements using the pHyter by comparison with benchtop spectrophotometric seawater pH measurements, measurement of a certified pH standard, and comparison with a proven in situ instrument, the iSAMI-pH. These results show a pHyter pH measurement accuracy of ±0.046 pH or better, which is on par with interlaboratory seawater pH measurement comparison experiments. We also demonstrate the pHyter's ability to conduct both temporal and spatial studies of coastal ecosystems by presenting data from a coral reef and a bay, in which the pHyter was used from a kayak. These studies showcase the instrument's portability, applicability, and potential to be used for community science, STEM education, and outreach, with the goal of empowering people around the world to measure pH in their own backyards.
KW - chemical sensor
KW - coastal ocean monitoring
KW - colorimetric pH measurement
KW - meta-cresol purple
KW - science education
UR - http://www.scopus.com/inward/record.url?scp=85140933651&partnerID=8YFLogxK
U2 - 10.3390/s22207924
DO - 10.3390/s22207924
M3 - Article
C2 - 36298277
AN - SCOPUS:85140933651
SN - 1424-8220
VL - 22
JO - Sensors (Basel, Switzerland)
JF - Sensors (Basel, Switzerland)
IS - 20
M1 - 7924
ER -