Direct determination of sulfite in food samples by a biosensor based on plant tissue homogenate

Inverse photopyroelectric (IPPE) spectroscopy, a novel variant among the photothermal spectroscopies, has been used for direct determination of ( Kρc)½ in a variety of food samples. The method appears capable of thermal characterization, and when combined with more mature techniques may prove useful in food products industry and storage.

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Rapid direct determination of ammonium and nitrate in soil and plant tissue extracts

Communications in Soil Science and Plant Analysis ◽

10.1080/00103629009368319 ◽

1990 ◽

Vol 21 (13-16) ◽

pp. 1519-1529 ◽

Cited By ~ 83

Author(s):

R.M. Carlson ◽

R.I. Cabrera ◽

J.L. Paul ◽

J. Quick ◽

R.Y. Evans

Keyword(s):

Plant Tissue ◽

Direct Determination ◽

Tissue Extracts

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New Methods in the Synthesis of (Meth)Acrylamides and Application Chelating Resin for Determination of Trace Metals in Certified Reference Materials and Waters

Trace Metals in the Environment - New Approaches and Recent Advances ◽

10.5772/intechopen.88685 ◽

2021 ◽

Author(s):

Cengiz Soykan

Keyword(s):

Trace Metals ◽

Human Health ◽

Certified Reference Materials ◽

Direct Determination ◽

Food Samples ◽

Chelating Resin ◽

Polymer Resin ◽

New Methods ◽

Instrumental Methods

The waste of trace metals are led the pollutions of water, soil and air. That’s why the accurate and sensitive identification of amount of trace metals in food samples and environment are gained importance in analytical chemistry because of their toxicity to human health. Besides, the direct determination of trace metals, presented at very low concentration especially in real samples, is difficult. In this content, before determination of trace metals by instrumental methods can be achieved successfully using separation/preconcentration procedures. The different synthesized chelating polymer resin adsorbents are successfully used for the SPE of trace metals. The trace metals, such as Cu, Cr, Co, Mn, Zn and Fe, are necessary for human health, when it has been taken at certain limits. But, the trace metals, such as Hg, Cd, Pb, Ni and As are toxic metals for the human body. About this, there are studies on the determination of trace elements and mineral in food samples and environment. In this study, new methods in the synthesis of (meth)acrylamides and use as a sorbent in the trace metals extraction was identified.

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Simple Flow-Based System with an In-Line Membrane Gas–Liquid Separation Unit and a Contactless Conductivity Detector for the Direct Determination of Sulfite in Clear and Turbid Food Samples

Membranes ◽

10.3390/membranes10050104 ◽

2020 ◽

Vol 10 (5) ◽

pp. 104

Author(s):

Aulia Ayuning Tyas ◽

Thitaporn Sonsa-ard ◽

Kanchana Uraisin ◽

Duangjai Nacapricha ◽

Phoonthawee Saetear

Keyword(s):

Direct Determination ◽

Gas Diffusion ◽

Food Samples ◽

Hydrophobic Membrane ◽

Liquid Separation ◽

Separation Unit ◽

Dried Fruit ◽

Simple Flow ◽

So2 Gas

This study presents a simple flow-based system for the determination of the preservative agent sulfite in food and beverages. The standard method of conversion of sulfite ions into SO2 gas by acidification is employed to separate the sulfite from sample matrices. The sample is aspirated into a donor stream of sulfuric acid. A membrane gas–liquid separation unit, also called a ‘gas-diffusion (GD)’ unit, incorporating a polytetrafluoroethylene (PTFE) hydrophobic membrane allows the generated gas to diffuse into a stream of deionized water in the acceptor line. The dissolution of the SO2 gas leads to a change in the conductivity of water which is monitored by an in-line capacitively coupled contactless conductivity detector (C4D). The conductivity change is proportional to the concentration of sulfite in the sample. In this work, both clear (wine) and turbid (fruit juice and extracts of dried fruit) were selected to demonstrate the versatility of the developed method. The method can tolerate turbidity up to 60 Nephelometric Turbidity Units (NTUs). The linear range is 5–25 mg L−1 SO32− with precision <2% RSD. The flow system employs a peristaltic pump for propelling all liquid lines. Quantitative results of sulfite were statistically comparable to those obtained from iodimetric titration for the wine samples.

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