Polypropylene Vessels Research Articles

Assessment of Semi-autotrophic Hydroponics on in vitro propagated Jamaican Sweet Yam (Dioscorea alata) - Analysis of Variance and Principal Component Analysis

Objective: Despite its benefits, plant tissue culture tends to incur a high production cost hence the need for cost-reduction strategies, especially with regards to acclimatization. One such strategy is to use semi-autotrophic hydroponics (SAH). SAH is a novel, low-cost technology that has been designed for the high-ratio and rapid propagation of clonal or vegetatively propagated crops. Sweet yam is a major export commodity of Jamaica and there is need to produce disease-free plants that require less pampering during hardening. The aim of this study is to analyze SAH in tissue culture of Jamaican sweet yams. Methods: Rooted sweet yam (Dioscorea alata) in vitro cultures were transferred to a commercial sphagnum peat moss based potting substrate, with vermiculite and fine calcitic and dolomitic limestone and the SAH system was run in a growth chamber at a tissue culture facility. Six tissue culture yam plantlets were incubated in polypropylene vessels and placed on separate shelves with north facing rows and south facing rows. Samples were treated with commercial fertilizer and controls were treated with tap water. Results: Fertilized plants showed significantly higher mean number of nodes (8.0±2.2 and 7.5±1.8) compared to non-fertilized plants (4.0±0.9 and 5.0±2.1) and significantly higher maximum leaf area index (41.42±15.49cm2 and 35.58±16.93cm2) versus non-fertilized plants (19.17±6.42cm2 and 23.58±6.55cm2). Fertilizer significantly reduced the mean number of mini tubers per plant (0.67±0.52). Non-fertilized (control) produced 2.50±1.05 and 1.83±0.41 mini tubers per plant. The mean mini tuber yields per plant were significantly reduced from 1.05±0.26g and 1.00±0.83g in non-fertilized (controls) to 0.28±0.30g and 0.34±0.40g in fertilized treatments. Principal Component Analysis (PCA) revealed three principal components accounting for 81.47% of the observed variance. PC1, 2 and 3 accounted for 39.28%, 30.49% and 11.64% of the variance respectively. PC1 described factors responsible for the vegetative growth, PC2 factors for mini tuberization and PC3 effects due to positioning of plants on shelves. Conclusion: SAH is a very flexible and adaptable technique which was found to be very useful in the acclimatization of tissue culture for Jamaican sweet yam plants. Commercial fertilizer application was found to be an efficient means of nutrient addition to promote vegetative growth. Fertilizer application significantly increased the number of nodes and maximum leaf area while it significantly reduced tuber quantity and yield. The ANOVA and PCA showed that fertilizer application was positively correlated to vegetative production factors while it was negatively correlated to mini tuber yield.

Determination of Cl and S in crude oil by ICP-OES after sample digestion by microwave-induced combustion in disposable vessels

A simple, fast and promising sample preparation method based on microwave-induced combustion in disposable vessels (MIC-DV) was developed for Cl and S determination in crude oil by inductively coupled plasma optical emission spectrometry (ICP-OES). The MIC-DV consists of a new approach of conventional microwave-induced combustion (MIC). For the combustion, crude oil was pipetted on a disk of filter paper and placed on a quartz holder, followed by the addition of igniter solution (40 μL of 10 mol L−1 NH4NO3). The quartz holder was inserted into a commercial 50 mL disposable polypropylene vessel containing the absorbing solution, which was then inserted in an aluminium rotor. The combustion occurs under atmospheric pressure in a domestic microwave oven not compromising the operator's safety. The following parameters of combustion were evaluated: type, concentration and volume of absorbing solution, sample mass and the possibility of performing consecutive combustion cycles. Using MIC-DV, up to 10 mg of crude oil were efficiently digested, using 2.5 mL of ultrapure H2O as absorbing solution. Moreover, up to 5 consecutive combustion cycles were possible without analyte losses, reaching a total sample mass of 50 mg. The MIC-DV method was validated according to Eurachem Guide recommendations. Results obtained for Cl and S by MIC-DV were in agreement with those obtained using conventional MIC, as well as those obtained for S in a certified reference material of crude oil (NIST 2721). Analyte spike recovery experiments were performed and recoveries at three concentration levels ranged from 99 to 101% for Cl and from 95 to 97% for S, indicating a good accuracy. The limit of quantification achieved by ICP-OES after MIC-DV were 73 and 50 μg g−1 for Cl and S respectively, applying 5 consecutive combustion cycles.

Methodical approaches to scale-up measurement of glyphosate concentration using HPLC-FLD

Introduction. Traditionally, the hygienic assessment of working conditions when using glyphosate preparations, an extremely popular herbicide in the world, is based on the use of thin layer chromatography. In this paper, alternative approaches are considered. On the basis of experimental data, the conditions for the analysis of glyphosate content in air by high performance liquid chromatography were optimized. Material and methods. All work with glyphosate solutions was carried out in polypropylene vessels. Sampling from the air medium was carried out on a medium filtration filter (“blue ribbon”). Subsequent extraction was carried out with water. The measurements were performed by high performance liquid chromatography with a fluorimetric detector at an excitation wavelength of 270 nm and an emission wavelength of 313 nm. To transfer glyphosate to a molecule with fluorimetric properties after derivatization of glyphosate in an alkaline medium using 9-fluorenylmethyl chloroformate by heating and washing off the excess of the reagent with toluene. A C18 reverse phase column was used; ammonium acetate with the addition of acetic acid and acetonitrile were used as eluents. Results. Approbation of the developed technique was carried out on real samples taken during ground treatment of fallow fields and lands of industrial territories with glyphosate preparations. The detected levels of glyphosate did not exceed the lower limit of quantitative determination: 0.5 mg/m3 in the air of the working area and 0.025 mg/m3 in the atmospheric air (with maximum allowable concentrations of 1.0 and 0.1 mg/m3, respectively). Limitations. The study considers a limited number of chromatographic columns. The study is performed on 25 model samples of the air of the working area and atmospheric air. Conclusion. Based on the results of the work performed, methodological instructions “Measurement of glyphosate concentrations in the air by high-performance liquid chromatography” were formed and sent for metrological certification in the approved manner.

Anomalous systemic arterial supply to the left basal lung with a calcified abnormal vessel: a case report

BackgroundAnomalous systemic arterial supply to the normal basal segment of the left lower lobe is a congenital abnormality of the lung, frequently and is generally diagnosed at a young age. Surgery is generally recommended if symptoms such as blood sputum or fever are observed. Resection of the abnormal artery is often performed at an early age, with only few reports of surgery being performed at an older age. In addition, to the best of our knowledge, there are no reports on surgical treatment of abnormal calcified vessels to date. Herein, we have presented a case in which a calcified aberrant vessel of lung was resolved surgically.Case presentationA 65-year-old female, previously diagnosed with anomalous systemic arterial supply to the left normal basal segment of the left lung lower lobe of lung was under observation on the basis of being asymptomatic.The patient presented to the emergency room with the chief complaint of blood in the sputum and she was referred to our hospital for a surgery. Computed tomography showed circumferential calcification of the intima of the abnormal vessel, which might have contributed to incomplete resection of the artery if automatic sutures were used. Thus, the abnormal vessel was ligated and dissected using pledgeted 4–0 polypropylene sutures and vessel clips under open thoracotomy followed by left lower lobectomy. The patient was discharged seven days after surgery without any serious surgical complications.ConclusionsVascular congenital anomalies of the lung are often operated at a young age presenting due to the associated symptoms. However, even if the disease is discovered incidentally and does not cause any symptoms or calcification in the aberrant artery, early surgical intervention is important due to the possibility of calcification occuring in the future. This can help minimize the degree of surgical invasion.

Improved electrical driving current of electrochemical treatment of Per- and Polyfluoroalkyl Substances (PFAS) in water using Boron-Doped Diamond anode

Emerging Per- and Polyfluoroalkyl Substances (PFAS) in water resources is toxic contaminants, which has negative impacts on human health and the environment. Electrochemical Oxidation (EO) is a promising treatment technology to manage water pollutants. The purpose of this study is to develop an efficient EO system to remove PFAS with reducing physical resistance of titanium connector using Boron-Doped Diamond (BDD) and titanium (Ti) electrodes All experiments were performed in a batch reactor through a polypropylene vessel containing 350 mL of Milli-Q water spiked with Perfluorooctanoic Acid (PFOA), Perfluorohexane sulfonate (PFHxS), and Perfluorooctane Sulfonate (PFOS) at concentrations of 1 mg L−1. Two types of electrolytes called sodium sulfate (Na2SO4) and sodium chloride (NaCl) were mixed into the solution. Reactions were performed with a BDD anode as a working electrode and a titanium cathode. The electrode surface area was 78.5 cm 2 with a plate distance of 3 cm. The electrical connectors (Ti wire) physically reduced the resistance from 9 Ohm to 7 Ohm which improved the driving capability of electric current. Results show that the electrochemical oxidation system with low resistance demonstrated higher removal efficiency for PFOS, PFHxS, and PFOA increased by 89.1%, 88.1%, and 94.0%, respectively, with low energy consumption. The decomposition efficiency of PFAS was higher because the electron transfer magnitude of current affects the rate of electrolysis oxidation. Meanwhile, the conductivity with low resistance increased approximately 1.3 times when compared with resistance at 9 Ohm. In addition, the Dimond electrode and titanium electrode present high efficiency in PFAS removal in water. Although BDD anode service life was not the focus of this study, no decreasing trend, determined for PFAS, was observed throughout the approximately 10 batch experiments (50 h) performed with a BDD anode.

Efficient production of fungal spores by the combination of reduction of nitrogen source content and embedding of hydrophobic polymer in an agar plate

Fungal sporulation is affected by many environmental factors, for example, we previously observed that embedding of a hydrophobic polymer net in an agar plate medium significantly accelerates spore formation of some fungi. Here, it was found that the fungal spore formation depended on the surface hydrophobicity of cultivation vessels used for the plate cultivation. In a polypropylene (PP) vessel, six fungal strains produced spores of 1.5 to 514.8 times of those growing in a glass vessel. The contact of vegetative hyphae on the surface of the vessels might trigger the fungal spore formation. Moreover, the spore formation was synergistically accelerated by the reduction of nitrogen source content in an agar plate medium and by the contact to hydrophobic polymers. The synergistic effect depended on the surface area of the hydrophobic polymer. Thus, the combination of the reduction of nitrogen source and the embedding of hydrophobic polymer is expected as a novel and effective procedure for production of fungal spores which are useful for the inoculum in fermentation industry and biocontrol agent in agriculture.

Developing the atomic spectrometry techniques for cobalt and nickel analysis

The existing methods standardized for to cobalt and nickel analysis, i.e. GOST 13047–2014, GOST 6012–2011 and GOST 8776–2010, don’t correspond to the current and future requirements to these metals in terms of impurities concentration. GOST 13047–2014 provides single-element analysis applications that establish a sample preparation for single element only, takes a lot of efforts and an extremely long time, consume a lot of chemical reagents and are associated with a significant harmful impact on the environment. Being a multielement technique, atomic emission spectrometry with DC-arc spectrum excitation is associated with a high consumption of chemical reagents and a significant environmental impact. It doesn’t allow determining the sulfur and other important impurities. All standard techniques are based on the obsolete principle to dissolve the samples in glass beakers on hot plates. The authors of this paper propose to standardize the methods of atomic emission spectrometry and mass spectrometry (MS) with inductively coupled plasma (ICP) to run cobalt and nickel analysis. 2.5 g samples of cobalt and nickel were proposed to decompose in a mixture of acids in closed polypropylene vessels heated in HotBlock systems at the temperature of 110 оC. This saved up to 5 cm3 of nitric acid and up to 5 cm3 of hydrochloric acid. The solutions of nickel and cobalt were analyzed for impurities on an iCAP 6500 Duo spectrometer at low plasma discharge power and using the base lines as an internal standard. This helped to improve the detection limits of impurities. To select optimal wavelengthes, full spectra of analyzed solutions were captured. Isotope 185Re was chose as internal standard and a collision and reaction cell was used to remove interfering polyatomic ions on an ICP-MS spectrometer iCAP Qc. Nickel and cobalt samples as well as CRMs were analyzed. The impurities detection limits with the current and future cobalt and nickel grades. The methods developed may create the basis for a new GOST standard applicable to cobalt and nickel analysis.

Hypobaric Packaging Prolongs the Shelf Life of Refrigerated Black Truffles (Tuber melanosporum).

Black truffle (Tuber melanosporum Vitt.) is a fine agro-food product known for its unique aroma and very limited shelf life (maximum of 5–7 days, room temperature). Hypobaric packaging at 30 kPa, a mix of 1% O2/99% N2, and 40% CO2/60% N2 were studied to prolong the shelf life of black truffle at 4 °C in sealed polypropylene vessels, compared to normal atmosphere. Epiphytic microbial population, firmness, weight loss, CO2 formation, and sensory properties were monitored weekly up to 35 days of storage and were related to the volatile profile. Principal components analysis revealed good correlation between the storage time and the decrease of firmness, and the increase of the microbial count and CO2 production. Only truffles stored under hypobaric conditions showed an acceptable quality after 14 days storage. Hypobaric packaging is a cheap strategy to prevent the swelling of vessels caused by respiration and can reduce the deviation from the high-quality level of the fresh product from one to at least two weeks.

Microwave-Induced Combustion in Disposable Vessels: A Novel Perspective for Sample Digestion.

A novel system for sample digestion was proposed based on microwave-induced combustion in disposable vessels (MIC-DV) for trace elements determination by inductively coupled plasma optical emission spectrometry (ICP-OES). As a proof of concept, botanical samples were digested by MIC-DV for further determination of Al, Cr, Cu, Fe, Mn, Sr, and Zn. The system consists of a quartz holder (a modified version of conventional MIC) placed inside disposable polypropylene (PP) vessels. The quartz holder was carefully designed to avoid excessive heating and damaging of the vessel walls. For the combustion, the PP vessels containing the quartz holder and sample were placed in a specially designed metallic rotor that prevents the heating of absorbing solution and allows the use of a domestic microwave oven for sample ignition. After combustion, the digestion vessel was shaken to ensure the analytes' absorption. The single-vessel principle was fulfilled, since no further dilution or liquid transfer was required and the same PP vessel used for digestion allowed solution storage until element determination. The influences of absorbing solution (diluted HNO3 and water) and sample mass (10 to 30 mg) were evaluated. By using the proposed MIC-DV system, low volumes of diluted absorbing solutions (5 mL of 1 mol L-1 HNO3) were possible, allowing the use of low reagent amounts and low energy consumption, since microwave irradiation is used only for sample ignition. The agreement with certified values ranged from 92 to 108% for all analytes, whereas the precision was below 15%. All of these advantages, combined with the use of low-cost disposable vessels and instrumentation, make MIC-DV suitable to be used for research and routine analysis.

One pot synthesis of ZnO hexagonal bugle beads in a closed polypropylene vessel: a simple hydrothermal way of synthesizing nanocrystalline ZnO photocatalyst for waste water treatments

Here, we report a novel and eco-friendly synthesis of zinc oxide (ZnO) hexagonal bugle beads in a closed polypropylene vessel. To the best of our knowledge, we are the first to report synthesis of ZnO nanostructures in a closed polypropylene vessel (a simple hydrothermal reactor). Structural, morphological, compositional and optical properties of the nanostructures were studied. X-ray diffraction (XRD) results demonstrate that ZnO nanocrystals grow in a single crystalline hexagonal phase. Scanning electron microscopy (SEM) reveal formation of nano-dimensional hexagonal bugle beads (base diameter ∼70 nm). The ZnO nanostructures were used to carry photocatalytic degradation of methylene blue (MB) dye. The beads show high photocatalytic performance against MB dye and degraded 89% of the dye in 120 min of UV light irradiation. The reusability test of zinc oxide bugle beads determine high stability of the photocatalyst.

Development of certified reference materials for physicochemical analysis. Certified reference solutions for the composition of aqueous aluminum, indium, magnesium, nickel and titanium

This paper presents information on the development and certification of reference materials (CRM) for the composition of aqueous aluminium, indium, magnesium, nickel, and titanium solutions.CRMs are represented by aqueous solutions containing aluminium, indium, magnesium, nickel, and titanium ions. CRMs have been packed into 5, 10 and 25 cm3 glass ampoules, as well as into 50 and 250 cm3 polypropylene vessels. The certified values of metal mass concentrations were established according to the preparation method.The certified value of the mass concentration of metal ions in the CRMs under study is found to vary within the range of 0.95–1.06 g/dm3. Both the relative expanded uncertainty (under k= 2) of the certified mass concentration and the relative standard uncertainty due to instability do not exceed the values of 0.8 % and 0.069 %, respectively. The developed CRMs are shown to have the shelf life of 3 years provided that standard storage conditions are ensured. The developed CRMs are included into the RF State Register of Certified Reference Materials under the following numbers: CRM 11122–2018, CRM 11123–2018, CRM 11124–2018, CRM 11125–2018, and CRM 11126–2018. The CRMs produced by the All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI) are characterized by the values of expanded uncertainty comparable to those of world leaders in the production of similar materials.

Green production of biodiesel over waste borosilicate glass derived catalyst and the process up-gradation in pilot scale

An efficient solid base catalyst derived from waste borosilicate glass, by its reaction with sodium hydroxide, is used here for the production of biodiesel from used cooking oil. The active phase of the catalyst is found to be Na2SiO3 and the material is highly effective in the production of fuel grade biodiesel till 4 numbers of repeated cycles. The catalyst is found to be tolerant to free fatty acid and water content in the oil feedstock. The procedure is up-graded in pilot scale with the aid of a set up made of polypropylene vessels where the formation of high pressure is avoided in the reactors by the continuous condensation of methanol, making the process a safer one. We report the use of a solid catalyst derived from waste materials in a pilot-scale biodiesel production unit for the first time, which has the potential to have an easy and cost-effective industrial scale up. The performance of the prepared biodiesel and its blends with petrodiesel in diesel engine is investigated and it is found that the biodiesel blend (B10) showed the best performance at all engine loads.

Serum and Urine Copper – Contamination and Stability

Summary Pre-analytical factors of variation need to be carefully considered and investigated in efforts to harmonize all aspects of the total testing process. This study aimed to evaluate contamination and stability in copper (Cu) analysis of serum and urine by flame atomic absorption spectroscopy (FAAS) and to compare the stability of urine Cu in controls and in D-penicillamine (D-PA) administration. Cu was measured by AAnalyst 400, Perkin Elmer, USA. Blood was collected in BD Vacutainer®SSTTM II Advance tubes and BD Vacutainer® Trace Element tubes. Sterile polyethylene and polypropylene vessels for collection, transportation, storage and preliminary preparation of samples were used in urinalysis. Stability in serum and 24 h urine was evaluated in two temperature regimens: 15-25°C and 2-8°C, for particular time of storage. No significant differences (p = 0.20) in Cu concentration was found between the two types of tested tubes with patient`s sera. The stability of the samples (serum and urine) was better at refrigeration temperature. In urine the stability was better in D-PA administration.Standardization of Cu analysis could be achieved by assessing the aspects of pre-analytical factors of variations.

Cadmium and lead in seafood samples determined by solid phase extraction and graphite furnace atomic absorption spectrometry

A sample preparation method has been developed to detect cadmium and lead in commercial frozen seafood samples. After being digested with concentrated HNO 3 in a closed polypropylene vessel, the clear sample solution was separated and preconcentrated by solid phase extraction using octadecyl silica membrane discs modified with 8-hydroxyquinoline prior to determination by graphite furnace atomic absorption spectrometry (GFAAS). The preconcentration conditions including pH, ligand quantity, eluent concentration, and volume were found to be effective with 10.0 mg of 8-hydroxyquinoline in 2.0 ml ethanol and pH 6.0. The retained cadmium and lead were efficiently eluted with 5.0 ml of 1.0 M HNO 3 and determined by GFAAS. The detection limits for cadmium and lead were 0.073 µg/l and 0.332 µg/l, respectively. The proposed method was tested with the certified reference material, DORM- 2 (Dogfish muscle), with good agreement. The recoveries were found to be 100-103% (n = 4) for Cd and 92-108% (n = 5) for Pb with relative standard deviation (n = 5) of 3% for Cd and 4% for Pb. The extraction was found to be unaffected by coexisting ions. The method was applied satisfactorily to the seafood samples and trace levels of cadmium and lead were found.

Design and construction of an quasi-adiabatic dissolution calorimeter with a novel dosing apparatus and a low heat capacity

A quasi-adiabatic calorimeter for determining the molar solution enthalpies (Δsol H) of non-volatile solids was constructed. The design of the instrument was adjusted to allow the determination of solution enthalpies of small amounts of solids. For that purpose, the novel apparatus for sample dosage with virtually negligible “blank heat” was built. The rather low heat capacity of the calorimeter was achieved by reducing the volume of the reaction cell (20 mL), the dosing unit, and electric elements (the thermistor and the heater). Good thermal isolation of the reaction cell from the surroundings was accomplished by placing the cell into an evacuated polypropylene vessel. A computer program for processing the calorimetric data according to modified Regnault–Pfaundler method was written. The performance of the calorimeter was tested by determining the heats of the reactions serving as thermochemical standards at 25 °C (the dissolution of KCl and NaCl in water and the dissolution of tris(hydroxymethyl)-aminomethane in 0.1 mol dm−3 HCl(aq)). The obtained data were in very good agreement with the literature values.

The impact of cell culture equipment on energy loss

Light energy of discrete wavelengths supplied via lasers and broadband intense pulsed light have been used therapeutically for many years. In vitro models complement clinical studies, especially for the elucidation of underlying mechanisms of action. Clarification that light energy reaches the cells is necessary when developing protocols for the treatment of cells using in vitro models. Few studies report on energy loss in cell culture equipment. The ability of energy from light with therapeutic potential to reach cells in culture needs to be determined; this includes determining the proportion of light energy lost within standard cell culture media and cell culture vessels. The energy absorption of cell culture media, with/without the pH indicator dye phenol red, and the loss of energy within different plastics and glassware used typically for in vitro cell culture were investigated using intense pulsed light and a yellow pulsed dye laser. Media containing phenol red have a distinctive absorption peak (560 nm) absent in phenol red-free media and restored by the addition of phenol red. For both light sources, energy loss was lowest in standard polystyrene tissue culture flasks or multi-well plates and highest in polypropylene vessels or glass tubes. The effects of phenol red-free media on the absorption of energy varied with the light source used. Phenol red-free media are the media of choice; polystyrene vessels with flat surfaces such as culture flasks or multi-well plates should be used in preference to polypropylene or glass vessels.

Time-Dependent Determination of HF Formation in LiPF6 -Containing Electrolytes in Different Cell Types by Spectroscopic Ellipsometry

A novel experimental technique was developed to investigate HF formation in organic carbonate based electrolytes containing LiPF6. Using spectroscopic ellipsometry, aging and thermal decomposition of the electrolyte were monitored in a standard glass cell and in a polypropylene vessel. The amount of HF generated was determined by following the etching rate of a thin silicon dioxide layer on a silicon wafer in contact with the electrolyte. The material of cell construction clearly influenced the etching rate of the SiO2 sensor and affected the rate of degradation.

コンクリートのスケーリング劣化に及ぼす凍結防止剤の影響

In order to evaluate resistance of salt scaling of concrete, the new evaluation test method with small amount of sample for short period was investigated in this study. Test method proposed was as follows：Mortar cured after 28 days was cut into cubes of less than 1cm. Various deicer solution of 40ml is poured into 100ml polypropylene vessels with three cubes of mortar（about 4g）. Freeze and thaw cycles charged these vessels. After several cycles, these cubes were observed and sieved with 2.5mm. Each residue was weighed. The freeze-thaw resistance was evaluated by use of the residues of each sieve. The residue of each sample was also characterized by SEM and mercury porosimetry. Salt scaling resistance remarkably differs by the kind of deicers used. It was obtained that according to freeze-thaw cycles, crack proceeded from the surface to center of cubes through the transition zone between aggregate and cement paste by the deterioration of SEM image and pore structure of cubes residue. Salt scaling resistance with magnesium chloride, magnesium acetate and magnesium nitrate is proved be quite smaller than those with other deicers, because magnesium hydroxide were precipitated on the surface of concrete with each magnesium salt solution and film of magnesium hydroxide have a role to protect concrete surface from salt scaling.小片凍結融解試験法は、スケーリング劣化の早期判定が可能であり、小型供試体を使用するため、供試体の状況をそのまま観察できるという有効性がある。本研究では、小片凍結融解試験法の改良を行ったうえで、11種の凍結防止剤を用い、それぞれの濃度（1、3、6mass％）において、スケーリング劣化に及ぼす影響を検討した。マグネシウムを含む凍結防止剤を使用した場合、他の凍結防止剤に比べて、スケーリング劣化は小さい。この原因は、硬化体表面に新たに水酸化マグネシウムが析出し、スケーリングの保護層の役割を果たすことによると判明した。

ROOTING OF MICROPROPAGATED TRANSSEXUAL PISTACIA TEREBINTHUS L. PLANTS FROM BULGARIA

ISHS XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on the Challenge for a Sustainable Production, Protection and Consumption of Mediterranean Fruits and Nuts ROOTING OF MICROPROPAGATED TRANSSEXUAL PISTACIA TEREBINTHUS L. PLANTS FROM BULGARIA

Markedly Enhanced Purge‐and‐Trap Performance and Efficiency for the Determination of Ammonium Ion in High‐Salinity Water Samples

AbstractWe have previously developed a purge‐and‐trap (P&T) preconcentrator, useful for the determination of trace amounts of ammonium ion in high‐salinity water samples by ion chromatography (IC). In this study, we succeeded in improving the P&T system to markedly enhance performance and efficiency for the determination of ammonium in high‐salinity water samples. Compared to the previous work, the background signal was reduced by a factor of 9. The maximum overall collection efficiency increased greatly from 64% to 97%. With the modified P&T system, this method can be applied to a wide ammonium concentration range of 5 orders of magnitude. These were attributed to the substitution of polypropylene vessels for glass ones, the improvement of the gastight of the P&T system, the increase of the liquid depth in the purge vessel, and the use of 10 mM sulfuric acid as the trapping solution for high ammonium concentration samples. Interferences of 20 native amino acids to the ammonium determination are slightly positive, but also negligible except asparagine and glutamine. The proposed method has been successfully applied to the accurate determination of wide levels of ammonium in seawater and sweat samples.