Quantitative pH assessment of small-volume samples using a universal pH indicator

Brown, Jeffrey D.; Bell, Nathaniel; Li, Victoria; Cantrell, Kevin

doi:10.1016/j.ab.2014.06.001

Cited by 7 publications

(3 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hue analysis of steady-state solutions using a universal pH indicator was implemented by Brown et al [46] and was the inspiration for its use in this work. This investigation used a single pH indicator to simplify solution behavior.…”

Section: Appendix Imaging Of Bromothymol Bluementioning

confidence: 99%

Liquid dynamics in response to an impinging low-temperature plasma jet

Brubaker¹,

Ishikawa²,

Kondo³

et al. 2018

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

The liquid-phase behavior induced by an atmospheric pressure plasma jet impinging onto water-based solutions was experimentally investigated. An increase in cavity size and circulation size resulting from an increase in impact force of the plasma jet with respect to a helium gas jet were observed through particle image velocimetry and cavity measurements. The increase in circulation size due to plasma discharge was larger than the increase solely due to an increase in jet impact force, suggesting additional shear along the liquid free surface evidenced by schlieren images of plasma-induced gas flow adherence after impingement. Liquid evaporation rate increased and mean liquid temperature decreased due to plasma effects on jet behavior. Plasma-induced decreases in liquid pH and temperature were contained within the circulation flow, leading to strong pH and temperature gradients within the liquid volume. Areas treated by the jet became acidic and remained more acidic than other portions of the liquid due to circulation vortices, highlighting the consequences of jet and liquid vessel parameters for plasma jet-liquid applications.

show abstract

Section: Appendix Imaging Of Bromothymol Bluementioning

confidence: 99%

Liquid dynamics in response to an impinging low-temperature plasma jet

Brubaker¹,

Ishikawa²,

Kondo³

et al. 2018

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…More complex methods of quantifying acidity require expensive instrumentation, what makes the usage of pH indicators still important. 10 A relevant application of pH indicators concerns the monitoring of biochemical processes through color changes at visible wavelengths representing protonation and deprotonation of species. 11 Several dyes have been used as pH indicators by the reversible action of acid and base forms.…”

Section: Introductionmentioning

confidence: 99%

New 9-Aminoacridine Derivative: Synthesis, Study and Potential Application as pH Indicator in Organic Solvents

Stroppa¹,

Glanzmann²,

Duarte³

et al. 2017

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

In this work, we describe the synthesis of a novel 9-aminoacridine derivative that presents surprisingly different colors when exposed to neutral, acidic or basic mediums with potential application as pH indicator in organic solvents. Furthermore, pKa and molar absorptivity values were determined and theoretical studies supported by density functional theory (DFT) calculations were performed to elucidate the different structures of this compound.Keywords: 9-aminoacridine derivative, pH indicator, organic medium Introduction 9-Aminoacridine (9-AA) is a polycyclic heteroaromatic compound with three fused rings that can be used as specific fluorescent.1,2 Its derivatives, which also have fluorescence properties and are typically colored, have a wide range of applications such as biological activity 3 against neurodegenerative diseases and protozoal parasites. 4 The anticancer effect of nitro-9-aminoacridine derivatives is reported in the literature. 5,6 The 9-AA is also described to be a suitable matrix for the matrix assisted laser desorption/ionization (MALDI) and can even be used as indicator of transmembrane pH difference.7-9 A pH indicator highlights changes in the hydrogenionic potential and can be used to determine chemical processes involving acids and bases. More complex methods of quantifying acidity require expensive instrumentation, what makes the usage of pH indicators still important. 10A relevant application of pH indicators concerns the monitoring of biochemical processes through color changes at visible wavelengths representing protonation and deprotonation of species.11 Several dyes have been used as pH indicators by the reversible action of acid and base forms. 12The pKa value is an important physicochemical parameter to predict the ionization state of a substance for the measurements of pH-dependent molecular properties (solubility and lipophilicity, for example) and in applications such as liquid chromatography and capillary electrophoresis for the separation of ionizable compounds. 13,14 There are several methods to determine pKa values, such as potentiometric titration, 15 ultravioletvisible (UV-Vis) absorption spectroscopy, 16 calorimetry, 17 nuclear magnetic resonance (NMR) spectroscopy, 18 and capillary electrophoresis.19 These are useful techniques for the determination of equilibrium constants due to its accuracy and reproducibility.In this work, it was synthesized the compound 2,4,5,7-tetranitro-9-aminoacridine (TNA), introducing four nitro groups in the aromatic rings of 9-AA (Figure 1), and the new derivative presented different colorations when exposed to neutral, acidic or basic mediums. Moreover, we performed a potentiometric titration to determine its pKa values in different mediums and we also confirmed the structures present in each medium through density functional theory (DFT) calculations. ExperimentalMaterials 9-Aminoacridine hydrochloride monohydrate 98% (Aldrich, São Paulo, Brazil), sulfuric acid 98% (Vetec, Rio de Janeiro, Brazil), nitric acid 65% (Cromoline, São Paulo, B...

show abstract

“…In comparison to our prototype, they achieved very good signals in a complectly different quantity of working volume but with a more expensive and complex setup. Brown et al (2014) reported a pH monitoring system for 100 µL samples in a 384-well plate using a digital camera. The captured RGB values of the pictures are converted into HSV or HSL color space.…”

Section: Introductionmentioning

confidence: 99%

Transmitted light pH optode for small sample volumes

Rogge

Zinn

Prosposito

et al. 2017

J. Sens. Sens. Syst.

View full text Add to dashboard Cite

Abstract. An innovative concept of a low-cost pH optode with working volumes of less than 150 µL is presented. The pH monitoring is based on the color changing effect of pH indicators. The optode includes an RGB color sensor patch TCS34725 from Adafruit, a controllable LED and reactor slides and is addressed by a selfwritten LabVIEW © software. Utilizing the hue value of the HSV color model, it is possible to analyze the color change of the indicator and estimate the pH value of the analyzed samples by exploiting sigmoidal fit models. Measurements carried out with phenol red and DMEM (Dulbecco's Modified Eagle's Medium) reported a standard error of calibration in the physiologic pH range (6.5-7.5) of ±0.04 pH units.

show abstract

Quantitative pH assessment of small-volume samples using a universal pH indicator

Cited by 7 publications

References 14 publications

Liquid dynamics in response to an impinging low-temperature plasma jet

Liquid dynamics in response to an impinging low-temperature plasma jet

New 9-Aminoacridine Derivative: Synthesis, Study and Potential Application as pH Indicator in Organic Solvents

Transmitted light pH optode for small sample volumes

Contact Info

Product

Resources

About