scholarly journals Changes in the infrared attenuated total reflectance (ATR) spectra of lignins from alfalfa stem with growth and development

2009 ◽  
Vol 74 (8-9) ◽  
pp. 885-892 ◽  
Author(s):  
Jordan Markovic ◽  
Jasmina Radovic ◽  
Ratibor Strbanovic ◽  
Danica Bajic ◽  
Miroslav Vrvic
Keyword(s):  
Growth And Development ◽  
Attenuated Total Reflectance ◽  
Klason Lignin ◽  
Chemical Changes ◽  
Total Reflectance ◽  
Development Stages ◽  
Spectrometric Technique ◽  
Acid Detergent Lignin ◽  
Predominant Component

Lignin is a poorly characterized polymer and its exact properties vary depending on both the species of the plant and its location within the plant. Three classes of lignins taken from alfalfa stem were examined. The investigation was concentrated on the determination of chemical changes in the lignins during growth and development by the attenuated total reflectance (ATR) infrared (IR) spectrometric technique. The spectrum of permanganate lignin was comparable to that of acid detergent lignin. The main differences were in the different relative absorbance of the peaks. The predominant component of acid detergent lignin and permanganate lignin was guaiacyl-type lignin. The predominant component of Klason lignin was syringyl-type lignin. A comparison between the signals from lignin in different development stages revealed the appearance of new peaks, which are indications of new bonds and changes in the structure of the lignins.

Biology and development of galls induced by Lopesia sp. (Diptera: Cecidomyiidae) on leaves of Mimosa gemmulata (Leguminosae: Caesalpinioideae)

2018 ◽  
Vol 66 (2) ◽  
pp. 161 ◽  
Author(s):  
Elaine Cotrim Costa ◽  
Renê Gonçalves da Silva Carneiro ◽  
Juliana Santos Silva ◽  
Rosy Mary dos Santos Isaias
Keyword(s):  
Growth And Development ◽  
Glandular Trichomes ◽  
Early Growth ◽  
Vascular Bundles ◽  
Nutritive Tissue ◽  
Development Stages ◽  
First Instar ◽  
Galling Insects ◽  
Late Growth

Analyses of gall biology and development allow determination of morphogenesis events in host-plant organs that are altered by galling insects. Currently, we assume that there is a correlation between Lopesia sp. instars and the alterations in gall tissues on Mimosa gemmulata that generate the gall shape. The development of Lopesia sp. (three larval instars, pupae and adult) correlates positively with gall growth, especially on the anticlinal axis. First-instar larvae are found in galls at the stage of induction, Instar 2 in galls at early growth and development, Instar 3 in galls at late growth and development, pupae in galls at maturation, and the adult emerges from senescent galls. At induction, the larva stimulates cell differentiation in pinnula and pinna-rachis tissues on M. gemmulata. At early growth and development stages, cell division and expansion are increased, and non-glandular trichomes assist gall closing. Homogenous parenchyma and neoformed vascular bundles characterise late growth and development. At maturation, tissues are compartmentalised and cells achieve major expansion through elongation. At senescence, galls open by the falling of trichomes, and mechanical and nutritive cells have thickened walls. The neoformed nutritive tissue nurtures the developing Lopesia sp., whose feeding behaviour influences the direction of cell elongation, predominantly periclinal, determinant for gall bivalve shape.

scholarly journals Collective Ion-Pair Single-Drop Microextraction Attenuated Total Reflectance Fourier Transform Infrared Spectroscopic Determination of Perchlorate in Bioenvironmental Samples

2018 ◽  
Vol 101 (4) ◽  
pp. 1145-1155 ◽  
Author(s):  
Swati Chandrawanshi ◽  
Santosh K Verma ◽  
Manas K Deb
Keyword(s):  
Ftir Spectroscopy ◽  
Ion Pair ◽  
Attenuated Total Reflectance ◽  
Sodium Iodide Symporter ◽  
Single Drop ◽  
Total Reflectance ◽  
Calibration Curves ◽  
Single Drop Microextraction ◽  
Perchlorate Concentration

Abstract Perchlorate (ClO4−) is an environmental pollutant that affects human health. Perchlorate acts as a competitive inhibitor of iodine uptake in the thyroid gland (sodium–iodide symporter inhibitor); thus, its determination is important for public health concerns. Water and milk constitute a significant portion of the human diet. Because regular intake leads to an increase in perchlorate concentration in the human body, the estimation of perchlorate is of great concern. In this work, ion-pair single-drop microextraction (SDME) combined with attenuated total reflectance (ATR)-FTIR spectroscopy has been developed for the determination of perchlorate in bioenvironmental (soil, water, dairy milk, breast milk, and urine) samples. Perchlorate was extracted in a single drop of methyl isobutyl ketone as an - with the cationic surfactant cetyltrimethylammonuim bromide under optimized conditions. The strongest IR peak (at 1076 cm−1) was selected for the quantification of perchlorate among three observed vibrational peaks. Eight calibration curves for different concentration ranges of perchlorate were prepared, and excellent linearity was observed for absorbance and peak area in the range of 0.03–100 ng/mL perchlorate, with r values of 0.977 and 0.976, respectively. The RSDs (n = 8) for the perchlorate concentration ranges of 0.03–100, 0.03–0.5, 0.5–10, and 10–100 ng/mL were in the range of 1.9–2.7% for the above calibration curves. The LOD and LOQ in the present work were 0.003 and 0.02 ng/mL, respectively. The extracted microdrop was analyzed directly by ATR-FTIR spectroscopy. The parameters affecting SDME, i.e, effect of pH, stirring rate, reagent concentration, microdrop volume, and extraction time, were optimized, and the role of foreign species was also investigated. F- and t-tests were performed to check the analytical QA of the method. A noteworthy feature of the reported method is the noninterference of any of the associated ions. The results were compared with those of the ion chromatography MS method, and a high degree of acceptability was found. The method was successfully applied for the determination of perchlorate in bioenvironmental samples.

scholarly journals Use of Attenuated Total Reflectance—Fourier Transform Infrared (ATR-FTIR) Spectroscopy in Combination with Multivariate Methods for the Rapid Determination of the Adulteration of Grape, Carob and Mulberry Pekmez

Foods ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 231 ◽  
Author(s):  
Nihal Yaman ◽  
Serap Durakli Velioglu
Keyword(s):  
Fourier Transform ◽  
Ftir Spectroscopy ◽  
Rapid Determination ◽  
Fourier Transform Infrared ◽  
Attenuated Total Reflectance ◽  
Chemometric Methods ◽  
Total Reflectance ◽  
Glucose Syrup ◽  
Model Efficiency

Pekmez, a traditional Turkish food generally produced by concentration of fruit juices, is subjected to fraudulent activities like many other foodstuffs. This study reports the use of Fourier transform infrared spectroscopy (FTIR) in combination with chemometric methods for the detection of fraudulent addition of glucose syrup to traditional grape, carob and mulberry pekmez. FTIR spectra of samples were taken in mid-infrared (MIR) range of 400–4000 cm−1 using attenuated total reflectance (ATR) sample accessory. Partial least squares-discriminant analysis (PLS-DA) and PLS chemometric methods were built for qualitative and quantitative analysis of pekmez samples, respectively. PLS-DA models were successfully used for the discrimination of pure pekmez samples and the adulterated pekmez samples with glucose syrup. Sensitivity and specificity of 100%, and model efficiency of 100% were obtained in PLS-DA models for all pekmez groups. Detection of the adulteration ratio of pekmez samples was also accomplished using ATR-FTIR spectroscopy in combination with PLS. As a result, it was shown that ATR-FTIR spectroscopy along with chemometric methods had a great potential for determination of pekmez adulteration with glucose syrup.

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