Universal HPLC Detector for Hydrophilic Organic Compounds by Means of Total Organic Carbon Detection

Abstract

Most quantifications are achieved by comparison of the signals obtained with the sample to those from a standard. Thus, the purity and stability of the standard are key in chemical analysis. Furthermore, if an analyte standard cannot be obtained, quantification cannot be achieved, even if the chemical structures are identified by a qualification method (e.g., high-resolution mass spectrometry). Herein, we describe a universal and analyte standard-free detector for aqueous-eluent-based high-performance liquid chromatography. This universal carbon detector (UCD) was developed based on total organic carbon detection. Separated analytes were oxidized in-line and converted to carbon dioxide (CO). Generated CO was transferred into the gas phase and collected into ultrapure water, which was followed by conductivity detection. The system can be applied as a HPLC detector that does not use an organic solvent as an eluent. The system can be calibrated with a primary standard of sodium bicarbonate for organic compounds. The universality and quantification were evaluated with organic compounds, including organic acids, sugars, and amino acids. Furthermore, the system was successfully applied to evaluation of the purity of formaldehyde in formalin solution, and determination of sugars in juices. The results show the universal carbon detector has good universality and can quantify many kinds of organic compounds with a single standard such as sodium bicarbonate.

Rapid Flow-Based System for Separation of Radioactive Metals by Selective Complex Formation

“…Therefore, UV irradiation with H 2 O 2 addition is effective for releasing Ga 3+ from the complex. It is also easy to apply UV radiation to a continuous-flow system using transparent tubing …”

Validação De Método Analítico Para Quantificação Do Fipronil Por Cromatografia Líquida De Alta Eficiência

“…A HPLC/UV é amplamente utilizada na detecção e determinação de inúmeros composto e ensaios analíticos encontrando forte aplicação para a indústria farmacêutica e de pesticidas que encontram no método a descrição completa das formulações e suas propriedades químicas (OHIRA et al, 2018). Como exemplo de composto analisado por HPLC tem-se o Fipronil.…”

Indirect Potentiometric pH Detection of Weak Acids with Absolute Quantitation by a Theoretical Approach

“…8 The post-column conversion of organic acids to CO 2 followed by gas diffusion scrubber collection and conductivity detection was performed as a universal detector by some authors. 9,10 The developed method can quantify the analyte without an analyte standard, and absolute quantitation was evaluated. The absolute quantitation is effective for the analyte, which is chemically unstable, easily adsorbs on the bottle surface, and easily evaporates.…”

“… Nonsuppressed conductivity detection with a weak acid as an eluent was also demonstrated. , The sensitivity of very weak acids (p K a > 7) with conductivity detection was improved by post-column mixing with an alkaline solution and permeative amine introduction after the separation . The post-column conversion of organic acids to CO 2 followed by gas diffusion scrubber collection and conductivity detection was performed as a universal detector by some authors. , The developed method can quantify the analyte without an analyte standard, and absolute quantitation was evaluated. The absolute quantitation is effective for the analyte, which is chemically unstable, easily adsorbs on the bottle surface, and easily evaporates.…”