Using the iPhone as a device for a rapid quantitative analysis of trinitrotoluene in soil.
Mobile 'smart' phones have become almost ubiquitous in society and are typically equipped with a high-resolution digital camera which can be used to produce an image very conveniently. In this study, the built-in digital camera of a smart phone (iPhone) was used to capture the results from a rapid quantitative colorimetric test for trinitrotoluene (TNT) in soil. The results were compared to those from a digital single-lens reflex (DSLR) camera. The colored product from the selective test for TNT was quantified using an innovative application of photography where the relationships between the Red Green Blue (RGB) values and the concentrations of colorimetric product were exploited. The iPhone showed itself to be capable of being used more conveniently than the DSLR while providing similar analytical results with increased sensitivity. The wide linear range and low detection limits achieved were comparable with those from spectrophotometric quantification methods. Low relative errors in the range of 0.4 to 6.3% were achieved in the analysis of control samples and 0.4-6.2% for spiked soil extracts with good precision (2.09-7.43% RSD) for the analysis over 4 days. The results demonstrate that the iPhone provides the potential to be used as an ideal novel platform for the development of a rapid on site semi quantitative field test for the analysis of explosives.
Department of Applied Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 Thailand; Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112 Thailand. Electronic address: aree.c@psu.ac.th.
Aree
A
Choodum
Proespichaya
P
Kanatharana
Worawit
W
Wongniramaikul
Niamh Nic
NN
Daeid
D040421:Cell Phone / Q000706:statistics & numerical data*; D003116:Color; D003124:Colorimetry / Q000295:instrumentation / Q000379:methods*; D053834:Explosive Agents / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D012987:Soil / Q000737:chemistry*; D013053:Spectrophotometry; D014303:Trinitrotoluene / Q000032:analysis*
D053834:Explosive Agents; D012987:Soil; D014303:Trinitrotoluene
Digital images; Red Green Blue color system; Trinitrotoluene; iPhone