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A field experiment was conducted at the University of Baghdad, Al-Jadriya in the spring season of 2021 for the potato crop under the influence of organic biofertilizers and water stress. Three levels of bio-organic fertilizers were used 0 (OM0), 1 (OM1) and 1.5 (OM2) ton ha-1 and three levels of irrigation 30 (I-30), 50 (I-50) and 75 (I-75) % water depletion were available to evaluate the role of bio-organic fertilizer and water stress in production functions and water use efficiency. I-30 treatment showed the highest water consumption ranging between 468 and 486 mm season-1 and decreased to 355-436 mm with water stress treatments I-75. The values of water consumption varied according to the levels of bio-organic fertilizer. The percentage of decrease in water consumption was 1.49 and 3.66% at low stress and reached 6.37% at high stress (I-75) compared to OM0. Both treatments I-30 and I-50 gave the same yield. Bio-organic fertilization led to an increase in the average yield of tubers 32.8 and 41.9% for both OM1 and OM2 compared to OM0. The production functions indicate that the yield increases by 0.057 ton ha-1 mm-1 of added water, and the water depth must be greater than 64.2 mm to obtain a yield that is 1.96 ton ha-1 more (significant limit) than the treatments in the experiment (1.96=0.057(Irr.). )-1.70). Fertilizer levels are higher than 1.9 ton ha-1 to obtain a higher yield of tubers by 26.29 tons/ha and the efficiency of water use is nil according to the water use function when the water consumption is higher than 692.7 mm. The response factor decreased when adding bio-organic fertilizer compared to OM0, which means that plants were not affected significantly under water stress conditions.

Objective The aim is to solve the analysis problems on the accurate determination of micro-trace impurity components in the high-quality development of China’s hydrogen energy industry. Methods For the quality analysis of hydrogen fuel, a gas dilution method based on the principle of critical flow orifices was established. As the major component of the sample to be tested is hydrogen rather than nitrogen, the math module of flow response factor is studied to investigate the influences on the flow of different gases. Results The dilution ratio of this method could achieve over 1∶1 000 with a relative expand uncertainty of better than 1%. The gas reference materials, namely formaldehyde and methane in hydrogen, are prepared in a 10-9 molar fraction level dynamically. The measured repeatability of concentrations of the gas reference materials is no more than 7%. The linear correlation coefficient R~2 of each diluted concentration is more than 0.999. Conclusions The analysis results of formaldehyde in nitrogen and in hydrogen respectively conclude that the math module of flow response factor is reliable, and the accuracy of this gas dilution method will be improved after a correction by flow response factor. [ABSTRACT FROM AUTHOR]

A modified elution condition for organic acids in meat chromatographed by aged sulfonated polystyrene-divinylbenzene (SPD) column was compared to common elution conditions in terms of efficiency, selectivity, resolution, peak shape, precision, and accuracy. The mobile phase concentration (mM), flow rate (mL/min), and column temperature (℃) under common elution conditions (CECs) changed from 10 to 25, 0.6 to 0.2, and 60 to 40 in modified elution (MEC), respectively. A total of 15 peaks were detected in both elution conditions. Seven of them were confirmed with the available authentic organic acid standards including citric, pyruvic, succinic, lactic, acetic, propionic, and butyric acid. A good efficiency, selectivity, resolution, and peak shape were obtained for organic acids chromatographed on aged SPD column with MEC compared to CEC. The analyte was quantified using external standard technique. High response factor, expected correction factor, better calibration sensitivity and repeatability, and also accuracy for organic acids were observed under MEC. In particular, when peak broadening was observed in the aged SPD column, good chromatographic separation could be obtained with MEC in terms of resolution and peak shape was associated with better precision and recovery for organic acids in meat. [ABSTRACT FROM AUTHOR]

We performed quantum chemical calculations based on the density functional theory (DFT) for the all-E- and several Z-isomers of three commercially important carotenoids (lycopene, β-carotene, and astaxanthin) and theoretically obtained the UV-Vis spectrum, response factor (determined from absorption intensities of the all-E- and the Z-isomers), and Q-ratio for each carotenoid isomer. The calculated spectra reproduced the experimental spectral shapes (e.g., the appearance of the Z-peaks and the blue shift of the main peaks for the Z-isomers) very well. The calculated response factors and Q-ratios also showed good agreement with reported values. Notably, response factors, which are difficult to determine experimentally, were well reproduced. These results suggest that quantum chemical calculations can be an effective tool for refining quantitative analysis and obtaining spectral data for carotenoids for which standards are difficult to obtain., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Masaki Honda reports financial support was provided by Japan Science and Technology Agency., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The quality control of medicinal cannabis should include quantification of as many cannabinoids as practicable in a routine analytical lab, to accurately reflect the quality of the product. However, the cost and availability of some cannabinoid standards is an impediment to their routine use. This work seeks to overcome this obstacle by analysing samples using relative retention times (RRT) and relative response factors (RRF), relative to CBD and CBDA reference standards which are readily available. A high-performance liquid chromatography-photodiode array method was developed to quantify ten cannabinoids (Δ9-THC, Δ8-THC, THCA-A, CBN, CBD, CDBA, CBC, CBDV, CBG, and CBGA) in dried cannabis inflorescence and cannabis oil. This method was validated according to ICH guidelines. The proposed method has detection limits ranging from 20 to 78 µg/g, which provided sufficient sensitivity for the panel of cannabinoids. Non-cannabinoid surrogate matrices were used for spike recovery studies to determine method accuracy – analyte recoveries for the inflorescence and oil ranged from 90.1 to 109.3% (inflorescence mean, 100.9%; oil mean, 99.6%). The RRT and RRF values determined independently by three analysts were comparable, indicating the method is robust. The validity of analysis using RRT and RRF was further confirmed by testing six inflorescence samples, as it was found that concentrations above the order of magnitude of the LoQ agreed satisfactorily (range, 95.0 to 111.9%; mean, 100.0%) with the concentrations obtained through the conventional approach of multipoint calibration using pure standards. The proposed method is therefore suitable for the rapid and simple determination of a panel of ten cannabinoids without having to repeatedly purchase every expensive pure standard. Accordingly, analysts in the medicinal cannabis field may explore the use of RRF and RRT for their methods and instruments.

Estuarine environmental capacity is the foundation for coastal biological diversity and self-purification capacity. Hence, studies on the marine environmental capacity (MEC) are the foundation for the total discharge control and water quality improvement of land-based pollutants. In the article, A calibrated two-dimensional hydrodynamic model was used to study the environmental characteristics of Sanmen Bay, including the tides, the residual currents, the tidal prism, and water exchange abilities. The model results were used to estimate the environmental capacity of the bay. Taking the pollution problem in Sanmen Bay as an example, the method of response factor, the sub-unit control method, and the phased control method were used to estimate the environmental capacity, pollutant amounts, and the pollutant reduction in the bay. The concentrations of COD, inorganic nitrogen, and acid salt in Sanmen Bay are spatially varied, with higher values occurring in the western part and in the inner bay. The half exchange time of the whole bay is about 23 days, and the exchange time of 95% water body is about 60 days. The evaluation of MEC cannot only provide technical support for the offshore aquaculture industries but also provide a scientific basis for the total control of terrigenous pollutants in coastal cities in Southern Zhejiang Province. [ABSTRACT FROM AUTHOR]

Estuarine environmental capacity is the foundation for coastal biological diversity and self-purification capacity. Hence, studies on the marine environmental capacity (MEC) are the foundation for the total discharge control and water quality improvement of land-based pollutants. In the article, A calibrated two-dimensional hydrodynamic model was used to study the environmental characteristics of Sanmen Bay, including the tides, the residual currents, the tidal prism, and water exchange abilities. The model results were used to estimate the environmental capacity of the bay. Taking the pollution problem in Sanmen Bay as an example, the method of response factor, the sub-unit control method, and the phased control method were used to estimate the environmental capacity, pollutant amounts, and the pollutant reduction in the bay. The concentrations of COD, inorganic nitrogen, and acid salt in Sanmen Bay are spatially varied, with higher values occurring in the western part and in the inner bay. The half exchange time of the whole bay is about 23 days, and the exchange time of 95% water body is about 60 days. The evaluation of MEC cannot only provide technical support for the offshore aquaculture industries but also provide a scientific basis for the total control of terrigenous pollutants in coastal cities in Southern Zhejiang Province.

Biodiesel is a renewable energy source that can be employed as an alternative fuel to fossil diesel. Monitoring samples in terms of fatty acid methyl esters (FAMEs) content using gas chromatography (GC) is a useful way to evaluate the quality of biodiesel produced. Fast GC can be used to reduce the time of analysis and consequently the costs, even though the equipment required for this may be expensive. Therefore, we developed and validated a Fast GC-response factor (Fast-GCRF) methodology using a low-priced nonpolar column, flame ionization detection (FID) and a standard chromatograph usually destined for conventional GC separations. The method was validated and applied to the quantification of FAMEs produced from various raw materials (soybean, cottonseed, canola, coconut, palm, sesame, sunflower, castor, corn, macauba, almond, peanut, chia seeds, residual frying oils, and chicken fat), being both selective and robust even when subjected to changes in sample preparation. The Fast GCRF method presented respective maximum relative standard deviation (RSD) values for instrumental precision, repeatability, and intermediate precision of 2.3 %, 3.6 %, and 2.8 %. When compared to conventional GC methodologies, accurate results with high degrees of agreement were obtained using the Fast-GCRF method, within an at least four times shorter analysis time. • Fast GC quantification of total biodiesel FAMEs produced from fifteen feedstocks. • Lower-cost instrumentation than usual fast GC FAMEs analysis. • Fast-GCRF proved to be accurate via recovery tests and method comparison. • Total analysis time at least four times shorter than the methods used as reference. [ABSTRACT FROM AUTHOR]

Sulfated polysaccharides (SPS) have attracted a lot of interest because of their diverse pharmacological functions. Numerous scientific studies have shown that SPS exhibit better biological activity than those that are not sulfated, such as immunomodulatory, anti-viral, and antioxidant activities. A crucial step to a better understanding of the mechanism of action and health effects is the production of high purity SPS. This calls for the development of selective assay techniques that can identify SPS preferentially without being influenced by other substances or the co-extracted polysaccharides. A universal modified toluidine blue (TB) assay was developed in this study to detect SPS. The assay procedures were conducted using different SPS standards including fucoidans from different biogenic sources, in addition to heparin and dextran sulfate. Spectroscopic response factor was calculated for each SPS which showed very good correlation (R2 = 0.998) with the corresponding sulfation degree. The proposed method was applied for determination of SPS content of crude fucoidan product using five different SPS standards. The method was cross validated by conducting ANOVA test to the obtained % recovery revealing that there is no significant difference between the results obtained by identical reference standard and four nonidentical natural SPS standards. This is the first report of a selective universal assay of SPS that enables the selective determination of SPS using a nonidentical reference standard. [Display omitted] • A novel sulfation degree corrected response factor-based TB assay was developed. • Sulfated polysaccharides with various sulfation degree were used for response factor calculation. • The calculated response factors showed a good correlation to the corresponding sulfation degree. • Absorbance normalization enabled response factor calculation. • Fucoidan content was determined using non-identical reference material. [ABSTRACT FROM AUTHOR]

• An innovative analytical method was developed combining UV and MS detection. • Response factors in MS for each oleuropein metabolite were calculated. • For the first time, conjugated derivatives of oleuropein aglycone were quantified. • This method could be applied to other phenolics with lack of commercial standards. The beneficial health effects of phytochemicals depend on their bioavailability and the form under which they reach systemic circulation, usually as phase II metabolites. The lack of authentic standards for these metabolites makes their quantification in biological samples challenging. A new analytical approach to get a more accurate quantification of oleuropein metabolites in biological samples after ingestion of olive leaf extract was proposed. This approach was based on the calculation of a response factor in QTOF MS for each metabolite, comparing their quantification in UV and MS using urine samples concentrated in the metabolites of interest. Glucuronide and sulfate conjugates of hydroxytyrosol and homovanillyl alcohol were more accurately quantified in plasma and urine and for the first time, oleuropein aglycone conjugates and their hydroxylated and hydrogenated derivatives were quantified after consumption of olive products. This approach could be extensible to the analysis of other phenolic metabolites when authentic standards are not available, opening a valuable method for bioavailability studies. [ABSTRACT FROM AUTHOR]

The use of mass spectrometry methods with triple quadrupole instruments is well established for quantification. However, the preparation of calibration curves can be time-consuming and prone to analytical errors. In this study, an innovative internal calibration (IC) approach using a one-standard calibration with a stable isotope-labeled (SIL) standard version of the endogenous compound was developed. To ensure optimal quantitative performance, the following parameters were evaluated: the stability of the analyte-to-SIL response factor (RF), the chemical and isotopic purities of the SIL, and the instrumental reproducibility. Using six clinically important endogenous steroids and their respective SIL standards, we demonstrated that RFs obtained on different LC-MS platforms were consistent. The quantitative performance of the proposed approach was determined using quality control samples prepared in depleted serum, and showed both satisfactory precision (1.3%–12.4%) and trueness (77.5%–107.0%, with only 3 values outside ±30%). The developed method was then applied to human serum samples, and the results were similar to those obtained with the conventional quantification approach based on external calibration: the Passing-Bablok regression showed a proportional bias of 6.8% and a mean difference of −5.9% between the two methodologies. Finally, we showed that the naturally occurring isotopes of the SIL can be used to provide additional calibration points and increase the accuracy for analytes with low concentrations. [Display omitted] • An internal calibration was developed for six endogenous steroids quantification in serum. • Fast quantification was achieved with one-standard calibration using SIL. • Trueness and precision were verified prior to application in real samples. • Accuracy for low concentrated analytes was enhanced by monitoring SIL isotopes. [ABSTRACT FROM AUTHOR]

Currently, the presence of many classes of volatile organic compounds (VOCs) in indoor air is well recognized. There is an impetus to accurately quantify airborne VOCs for the proper assessment of their human health risks. VOC standards prepared in a solvent are often vaporized in N 2 gas-filled sampling bags for external calibration as the use of grab sampling bags is a common practice for the collection of real ambient air samples. Such practices can nontheless be subject to many sources of biases in their calibration (e.g., VOC chemical reaction with the solvent, adsorption on the bag interior surface, or leakage). The main goal of this work is to measure the temporal stability of 11 VOC targets (benzene, toluene, o-xylene, styrene, propionaldehyde, n-butyraldehyde, isovaleraldehyde, valeraldehyde, acrylonitrile, isoprene, and methyl ethyl ketone) selected in this research over 24 h which started 10 min after the injection and vaporization of liquid-phase standards (all prepared in methanol solvent) into polyester aluminum (PEA) bags containing 1 atm N 2. Although all tested VOCs showed gradual decreases of their concentrations (e.g., >17% in 24 h), the aromatic hydrocarbon VOCs (namely BTXS) yielded the best relative recoveries (e.g., decreases of 11%–30% in 24 h) and relative errors (e.g., relative standard error (RSE) = 2.14–3.59%) in 5 replicate tests. A good linear relationship was established between the 24 h VOC relative recovery and molecular weight (R2 > 0.81). The results of this study offers valuable clues to properly reduce the bias in the calibration of gas-phase VOC standards when calibrating the system through the vaporization of liquid-phase VOC standards prepared in a solvent. [Display omitted] • A total of 11 VOCs were injected to and stored in polyester aluminum (PEA) bags. • Short-term changes in VOC concentrations in PEA bags were measured. • Their relative recovery was calculated at each time interval up to 24 h. • Aromatic VOCs showed enhanced stability relative to other types of VOCs. • Relative recovery of VOCs was predictable in relation to their molecular weight. [ABSTRACT FROM AUTHOR]