Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy for the Quantitative Analysis of Deuterium in Plasma: Application to Total Body Water Determination in Humans and Other Animals.

This research paper explores the use of Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy as a more efficient method for measuring deuterium concentrations in body fluids, with potential applications in determining total body water in humans and animals.

Introduction

• The paper begins with a discussion of the conventional methods for measuring deuterium, an isotope of hydrogen, in body fluids. This happens either through isotope ratio mass spectrometry or Fourier transform infrared transmission (FT-IR) spectroscopy.
• The preference for the FT-IR method is due to it being both less expensive and not as time-consuming. One notable drawback, however, is its lower sensitivity that needs larger sample volumes.

New Methodology

• In a pursuit for more effective alternatives, the researchers then look into another FT-IR spectroscopic method, attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR).
• The potential upside of this method is its possibility to deliver quicker analyses while requiring smaller sample volumes.
• The concentration range of deuterium assayed using ATR FT-IR in plasma falls within 0.5 to 2.5 mg mL, a range usually seen in tracer dilution measurements of total body water.
• The unique advantage of this approach lies in the fact that minimal sample preparation was required and the research saw a decrease in analysis time compared to the traditional FT-IR method.

Results

• The paper reports that samples were analyzed with high precision – the coefficient of variation (CV) was less than 0.5%.
• This level of precision was sustained even when analysing plasma volumes of only 10 µL.
• The method’s practical applications in determining total body water in humans and horses were also demonstrated in the study.

Conclusions and applications

• In sum, the research presents a simpler and quicker method to measure deuterium in plasma only needing smaller sample volumes.
• This method would be especially useful in pediatric settings where blood sampling needs to be kept at a minimum.