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The present study describes the trace analysis of 23 fluorinated aromatic carboxylic acids based on the dispersive solid-phase extraction (dSPE) technique using UiO-66-NH 2 MOF as efficient, recyclable sorbent, and GC-MS negative ionization mass spectrometry (NICI MS) as determination technique. All 23 fluorobenzoic acids (FBAs) were enriched, separated, and eluted in a shorter retention time; the derivatization was done by pentafluorobenzyl bromide (1% in acetone), in which the use of inorganic base K 2 CO 3 was improved by triethylamine to increase the lifespan of the GC column. The performance of UiO-66-NH 2 was evaluated by dSPE in Milli-Q water, artificial seawater, and tap water samples, and the impact of various parameters on the extraction efficiency was investigated by GC-NICI MS. The method was found to be precise, reproducible, and applicable to the seawater samples. In the linearity range, the regression value was found to be >0.98; LOD and LOQ were found to be in the range of 0.33-1.17 ng/mL and 1.23-3.33 ng/mL, respectively; and the value of the extraction efficiency was found to range between 98.45 and 104.39% for Milli-Q water samples, 69.13-105.48% for salt-rich seawater samples, and 92.56-103.50% for tap water samples with a maximum RSD value of 6.87% that confirms the applicability of the method to different water matrices., (© 2023. Springer-Verlag GmbH Germany, part of Springer Nature.)

Flexible paper-based sensors may be applied in numerous fields, but this requires addressing their limitations related to poor thermal and water resistance, which results in low service life. Herein, we report a paper-based composite sensor composed of carboxylic carbon nanotubes (CCNTs) and poly- m -phenyleneisophthalamide (PMIA), fabricated by a facile papermaking process. The CCNT/PMIA composite sensor exhibits an ability to detect pressures generated by various human movements, attributed to the sensor's conductive network and the characteristic "mud-brick" microstructure. The sensor exhibits the capability to monitor human motions, such as bending of finger joints and elbow joints, speaking, blinking, and smiling, as well as temperature variations in the range of 30-90 °C. Such a capability to sensitively detect pressure can be realized at different applied frequencies, gradient sagittas, and multiple twists with a short response time (104 ms) even after being soaked in water, acid, and alkali solutions. Moreover, the sensor demonstrates excellent mechanical properties and hence can be folded up to 6000 times without failure, can bear 5 kg of load without breaking, and can be cycled 2000 times without energy loss, providing a great possibility for a long sensing life. Additionally, the composite sensor shows exceptional Joule heating performance, which can reach 242 °C in less than 15 s even when powered by a low input voltage (25 V). From the perspective of industrialization, low-cost and large-scale roll-to-roll production of the paper-based sensor can be achieved, with a formed length of thousands of meters, showing great potential for future industrial applications as a wearable smart sensor for detecting pressure and temperature, with the capability of electric heating.

Ground spruce wood was extracted with water at 170 °C at four different pH levels (3.8, 4.0, 4.2 and 4.4) achieved by using phthalate buffers. Static batch extractions were carried out in an accelerated solvent extractor (ASE-300). The extracted non-cellulosic carbohydrates, predominantly galactoglucomannans (GGMs), were characterised mainly by sugar unit analysis and molar mass determination. Compared to extraction with plain water, extractions with phthalate buffer solutions gave similar yields of non-cellulosic carbohydrates, but gave up to 70% less monosaccharides, and consequently higher molar masses of extracted GGMs. Moreover, at these pH levels, the hydrolysis of acetyl groups were decreased by 40% compared to extraction with plain water, thus maintaining the water solubility of GGMs. It is concluded that hot water extraction of hemicelluloses in high-molar-mass form (average Mw about 10 kDa) from wood in good yields (8% of wood) demands appropriate control of pH, to a level of about 4., (Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.)