Gran method for end point anticipation in monosegmented flow titration

Aquino, Emerson Vidal de; Pasquini, Célio; Rohwedder, Jarbas José R.; Raimundo, Ivo M.; Montenegro, M. C. B. S. M.; Araújo, Alberto N.

doi:10.1590/s0103-50532004000100017

Cited by 4 publications

(5 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This limitation has been observed by other authors. 30 In the present work, solutions with concentrations lower than 3.0 x 10 -2 mol L -1 could be employed without risks of clogging the system. Some experiments were also performed employing the SIA approache.…”

Section: Resultsmentioning

confidence: 91%

Monosegemented flow potentiometric titration for the determination of chloride in milk and wine

Vieira¹,

Raimundo²,

Reis³

et al. 2003

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Este trabalho descreve um procedimento automático em fluxo monossegmentado para titulação potenciométrica aplicado à determinação de cloreto em leite e vinho. O sistema de fluxo foi desenvolvido com base em uma válvula solenóide de 6 vias, controlada por um microcomputador através de um programa escrito em VisualBasic 3.0. Um eletrodo indicador tubular de Ag 2 S seletivo a Cl -e um eletrodo de referência convencional de Ag/AgCl foram empregados. Um algoritmo baseado na diferença de potencial entre duas adições subsequentes de titulante foi desenvolvido, possibilitando a determinação do ponto final da titulação em, no máximo, 10 tentativas, com uma precisão melhor que 1,0%. O sistema proposto foi avaliado pela determinação de cloreto em leite e vinho, usando uma solução padrão de AgNO 3 como titulante. A exatidão foi avaliada comparando-se os resultados com aqueles obtidos pelo método da AOAC, não sendo encontradas diferenças significativas ao nível de confiança de 95%.An automated flow potentiometric titration procedure for the determination of chloride in milk and wine exploiting the monosegmented flow approach is described. The flow network was designed based on a six-way solenoid valve, controlled by a microcomputer running software written in VisualBasic 3.0, allowing selection of the titration conditions. An Ag 2 S tubular electrode selective for Cl -and a conventional Ag/AgCl electrode were employed as indicator and reference, respectively. An algorithm based on the potential difference between two subsequent titrant additions was developed, allowing to reach the end point in less than 10 attempts, with a precision better than 1.0%. The proposed system was evaluated by determining chloride in milk and wine, using a standard AgNO 3 solution as titrant. Accuracy was ascertained by comparing the results with those obtained using the AOAC procedure. No significant difference at a 95% confidence level was observed.Keywords: potentiometric titration, monossegmented flow, multicommutation, ion selective electrode, chloride in milk, chloride in wine IntroductionThe mechanisation of the potentiometric titration procedure was first described in 1914 1 and the introduction of flow injection analysis in 1975 2 improved this mechanisation, including for potentiometric and spectrophotometric titrations. [3][4][5] Flow injection titration usually employs a calibration step, in which the peak width (instead of height) is taken as the analytical parameter. The simplest approach, which was first proposed by Ruzicka et al. 6 in 1977, employs a single line manifold and is still being employed nowadays. 7,8 Different alternatives have been proposed to determine the stoichiometric point in a flow titration procedure. Continuous flow systems based on the ratio of sample and titrant flow rates have been exploited to achieve the end point. 9,10 In order to vary the flow rates of the solutions independently, two peristaltic pumps are necessary, which 260 Vieira et al. J. Braz. Chem. Soc. represents the main drawback of these...

show abstract

Section: Resultsmentioning

confidence: 91%

Monosegemented flow potentiometric titration for the determination of chloride in milk and wine

Vieira¹,

Raimundo²,

Reis³

et al. 2003

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…The advantage of this technique is that the characterisation of the endpoint is generally less dependent on the speed of measurement. A second advantage is that throughput of discrete batch titration can be increased by using a discrete flow titration, where each unique ratio is continuously generated, typically by syringe pumps, and the endpoint is detected inline [21,22] …”

Section: Resultsmentioning

confidence: 99%

“…A second advantage is that throughput of discrete batch titration can be increased by using a discrete flow titration, where each unique ratio is continuously generated, typically by syringe pumps, and the endpoint is detected inline. [21,22] Our design process is detailed in the decision tree shown in Figure 3. The high viscosity of our analyte precluded the use of discrete flow titration due to its tendency to clog and the difficulty of completely removing residue from tubing walls between discrete flow units.…”

Section: Design and Development Of The Ph Robotmentioning

confidence: 99%

pHbot: Self‐Driven Robot for pH Adjustment of Viscous Formulations via Physics‐informed‐ML**

Chitre,

Cheng,

Ahamed

et al. 2023

Chemistry Methods

View full text Add to dashboard Cite

AbstractpH adjustment is crucial for many industrial products, yet this step is typically performed by manual trial‐and‐error. A particularly industrially relevant yet challenging titration is that of adjusting viscous liquid formulations using weak, polyprotic titrants (usually citric acid). Handling of viscous, non‐Newtonian formulations, with such polyprotic acids preferred for their chelation and buffering effects make a robotic solution challenging. We present a self‐driving pH robot integrated with physics‐informed learning; this hybrid physical‐ML model enables automated titration with weak‐strong acid/base pairs. To deal with the high viscosities of these formulations, we developed specific automated mixing and cleaning protocols. We hit the target pH within two to five iterations over 250 distinct formulations in lab‐scale small‐batch (~10 mL and 12 samples) titrations. In the interest of scaling up to match industrial processes, we also demonstrate that our hybrid algorithm works at ~25× scale‐up. The method is general, and we open‐source our algorithm and designs.

show abstract

Section: Design and Development Of The Ph Robotmentioning

confidence: 99%

pHbot: Self-Driven Robot for pH Adjustment of Viscous Formulations via Physics-informed-ML

Chitre,

Cheng,

Ahmed

et al. 2023

Preprint

View full text Add to dashboard Cite

pH adjustment is crucial for many industrial products, yet this step is typically performed by manual trial-and-error. A particularly industrially relevant yet challenging titration is that of adjusting viscous liquid formulations using weak, polyprotic titrants (usually citric acid). Handling of viscous, non-Newtonian formulations, with such polyprotic acids preferred for their chelation and buffering effects make a robotic solution challenging. We present a self-driving pH robot integrated with physics-informed learning; this hybrid physical-ML model enables automated titration with weak-strong acid/base pairs. To deal with the high viscosities of these formulations, we developed specific automated mixing and cleaning protocols. We hit the target pH within two to five iterations over 250 distinct formulations in labscale small-batch (~ 10 mL and 12 samples) titrations. In the interest of scaling up to match industrial processes, we also demonstrate that our hybrid algorithm works at ~25x scale-up. The method is general, and we open-source our algorithm and designs.

show abstract

Gran method for end point anticipation in monosegmented flow titration

Cited by 4 publications

References 15 publications

Monosegemented flow potentiometric titration for the determination of chloride in milk and wine

Monosegemented flow potentiometric titration for the determination of chloride in milk and wine

pHbot: Self‐Driven Robot for pH Adjustment of Viscous Formulations via Physics‐informed‐ML**

pHbot: Self-Driven Robot for pH Adjustment of Viscous Formulations via Physics-informed-ML

Contact Info

Product

Resources

About