Borosilicate Glass Bottles Research Articles

Solving the retention time repeatability problem of hydrophilic interaction liquid chromatography

Hydrophilic interaction (liquid) chromatography (HILIC) has become the first choice LC mode for the separation of hydrophilic analytes. Numerous studies reported the poor retention time repeatability of HILIC. The problem was often ascribed to slow equilibration and insufficient re-equilibration time to establish the sensitive semi-immobilized water layer at the interface of the polar stationary phase and the bulk mobile phase. In this study, we compare retention time repeatability in HILIC for borosilicate glass and PFA (co-polymer of tetrafluoroethylene and perfluoroalkoxyethylene) solvent bottles. During this study, we observed peak patterns shifting towards higher retention times (for metabolites and peptides) and lower retention times (oligonucleotide sample) with ongoing analysis time when standard borosilicate glass bottles were used as solvent reservoirs. It was hypothesized that release of ions (sodium, potassium, borate, etc.) from the borosilicate glass bottles leads to alterations (thickness and electrostatic screening effects) in the semi-immobilized water layer which is adsorbed to the polar stationary phase surface under acetonitrile-rich eluents in HILIC with concomitant shifts in retention. When PFA solvent bottles were employed instead of borosilicate glass, retention time repeatability was greatly improved and changed from average 8.4 % RSD for the tested metabolites with borosilicate glass bottles to 0.14 % RSD for the PFA solvent bottles (30 injections over 12 h). Similar improvements were observed for peptides and oligonucleotides. This simple solution to the retention time repeatability problem in HILIC might contribute to a better acceptance of HILIC, especially in fields like targeted and untargeted metabolomics, peptide and oligonucleotide analysis.

Association between microbial water quality, sanitation and hygiene practices and childhood diarrhea in Kersa and Omo Nada districts of Jimma Zone, Ethiopia.

Diarrhea is one of the leading causes of child morbidity and mortality in low- and middle-income countries like Ethiopia. The use of safe drinking water and improved sanitation are important practices to prevent diarrhea. However, limited research has been done to link water supply, sanitation and hygiene practices and childhood diarrhea. Therefore, this study aimed at assessing the association between microbial quality of drinking water, sanitation and hygiene practices and childhood diarrhea. Community-based matched case-control study design was applied on 198 paired children from June to July 2019 in Kersa and Omo Nada districts of Jimma Zone, Ethiopia. Cases are children < 5 years of age with diarrhea during the two weeks before the survey. The controls are children without diarrhea during the two weeks before the survey. Twenty-five percent matched pair samples of water were taken from households of cases and controls. Data were collected using structured questionnaire by interviewing mothers/caregivers. A sample of water was collected in nonreactive borosilicate glass bottles and analyzed by the membrane filtration method to count fecal indicator bacteria. A conditional logistic regression model was used; variables with p-value less than 0.05 were considered as significantly associated with childhood diarrhea. A total of 396 (each case matched with control) under-five children with their mothers/caregivers were included in this study. In the analysis, variables like presence of under-five child in their home (AOR = 2.76; 95% CI: 1.33-5.71), wealth status (AOR = 5.39; 95% CI: 1.99-14.55), main sources of drinking water (AOR = 4.01; 95% CI: 1.40-11.44), hand washing practice before water collection (AOR = 4.28; 95% CI: 1.46-12.56), treating water at household level (AOR = 1.22; 95% CI: 0.48-3.09), latrine use all the times of the day and night (AOR = 0.22; 95% CI: 0.06-0.78), using pit as method of waste disposal (AOR = 4.91; 95% CI: 1.39-13.29) and use of soap for hand washing (AOR = 2.89; 95% CI: 1.35-6.15) were significantly associated with childhood diarrhea. Moreover, 30% of sampled water from cases and 26% of sampled water from controls families were free from Escherichia coli whereas all sampled water analyzed for Total coliforms were positive. We conclude that the main sources of drinking water, hand washing before water drawing from a storage container, domestic waste disposal place and use of soap for hand washing were the most important factors for the prevention of childhood diarrhea.

Water supply, sanitation and hygiene interventions and childhood diarrhea in Kersa and Omo Nada districts of Jimma Zone, Ethiopia: a comparative cross-sectional study

BackgroundDiarrhea is a major public health problem that disproportionately affects children in developing countries, including Ethiopia. Most of the diseases can be prevented through safe drinking water supply and provision of basic sanitation and hygiene. However, there is a paucity of information on childhood diarrhea related to interventions in kebeles (smallest administrative structure) where community-led total sanitation (CLTS) implemented and not implemented (non-CLTS). Thus, the aim of this study was to assess and compare the association of water supply, sanitation and hygiene interventions, and childhood diarrhea in CLTS implemented and non-implemented kebeles.MethodA comparative cross-sectional study was conducted in Kersa and Omo Nada districts of Jimma Zone, Ethiopia from July 22 to August 9, 2018. Systematically selected 756 households with under-5 children were included in the study. Data were collected through interview using structured questionnaires. Water samples were collected in nonreactive borosilicate glass bottles. The binary logistic regression model was used; variables with a p value < 0.05 were considered as significantly associated with childhood diarrhea.ResultsThe prevalence of childhood diarrhea in the past 2 weeks was 17.7% (95% CI: 13.9–21.5) in CLTS kebeles and 22.0% (95% CI: 17.8–26.2) in non-CLTS kebeles. The occurrence of childhood diarrhea, increased among children whose families did not treat drinking water at home compared to those who treated in both CLTS (AOR = 2.35; 95% CI: 1.02–05.98) and non-CLTS (AOR = 1.98; 95% CI: 0.82–4.78) kebeles. About 96% of households in CLTS and 91% of households in non-CLTS kebeles had pit latrine with and without superstructure. Children from families that used water and soap to wash their hands were 76% less likely to have diarrhea in CLTS kebeles (AOR = 0.76; 95% CI: 0.31–1.88) and 54% less likely to have diarrhea in non-CLTS kebeles (AOR = 0.54; 95% CI: 0.17–1.72) when compared to children from families who used only water. The odds of having diarrhea was 1.63 times higher among children whose families live in CLTS non-implemented kebeles compared to those children whose families live in CLTS implemented kebeles (AOR = 1.63; 95% CI: 0.98–2.68).ConclusionsNo significant difference was observed in the prevalence of childhood diarrhea between CLTS and non-CLTS kebeles.

Quantification of Trace Mercury in Water: Solving the Problem of Adsorption, Sample Preservation, and Cross-Contamination.

Adsorption, sample preservation, and cross‐contamination are the major impediments to the accurate and sensitive analysis of low‐level mercury samples. Common measures to deal with this issue are to use Teflon, quartz, or borosilicate glass bottles for sampling, standard solution and sample preservation with oxidative chemicals, to prepare standard solutions daily and to use dedicated glassware. This paper demonstrates that these measures are neither efficient nor effective. Two common laboratory sample containers (borosilicate volumetric glass flasks and polypropylene tubes) are investigated for the preparation and preservation of water samples and standard solutions of 0.2–1 µg L−1 with 2% HNO3. Mercury adsorption rates of 6–22% are observed within 30 min and after 48 days, the adsorption is greater than 98%. In stark contrast, no adsorption is found during a testing period of 560 days when the solutions are subject to potassium permanganate‐persulfate digestion. New glass flasks and polypropylene bottles are free of mercury contamination but reused flasks are a major source of mercury cross‐contamination. To minimize adsorption and cross‐contamination, standard solutions are treated by potassium permanganate‐persulfate or BrCl digestion, and each individual sample and standard solution should be stored and prepared in single‐use polypropylene bottle, without transference.

Assessing landfill leachate quality and leachate treatment efficiency using good sampling practices

A number of the compounds detected in landfill leachates have proved to be harmful to humans and to the natural environment. As a result, appropriate landfill leachate treatment methods must be developed, with the aim to reduce harmful concentrations of pollutants to levels which do not impose a threat to the natural environment. The complex nature of the leachates makes it difficult to select the most appropriate set of treatment methods for a specific landfill, and the actual efficiency of a treatment plant is measured in situ by comparing the quality of the water entering the plant with the quality of the water leaving the plant. The complex nature of the leachates puts high demands on the sampling, handling of sample before analyses, and analyses, as the character of the sample must not be altered. The demands increase with decreasing concentrations of the targeted compounds (µg/1 level or less). Despite this, no standard protocols for sampling and handling of leachate samples exist. The purpose of this study was to give examples of good sampling practices. Important aspects to consider during sampling and handling of samples are; i) sampling of nonhomogenized water bodies, ii) contamination, and iii) alterations of samples during collection and storage. It was found that a number of substances are enriched in the surface layer of a water body, why it was concluded that the surface layer is an important matrix to consider, both concerning the presence and the transport of harmful compounds. The risk of contamination during sampling was evaluated with the use of a field water blank, which was handled as a true water sample. It was found that despite careful handling contaminants were found at low concentrations (µg/1 level) in the field water blank, which indicated a severe risk of contamination during leachate sampling, handling of sample and/or analyses. Also in this study, the alteration of leachate samples during transport and storage was assessed. The results showed that preservation with 0.2 weight-% sodium azide immediately after sampling and storing at 48° C for a maximum of seven days in borosilicate glass bottles, resulted in the lowest loss of organic compounds from the samples. It has been evident since long that the reported character of sampled landfill leachates varies significantly. The variations can been assumed to sometimes origin from the sampling procedures used. In conclusion, the choice of sampling, transport, storage, and sample preparation before analyses is more crucial for the outcome of leachate characterisation studies than sometimes conceived.

Impact of sterilization methods on dissolved trace metals concentrations in complex natural samples: Optimization of UV irradiation

Sterilization is essential for discriminating biotic responses from abiotic reactions in laboratory experiments investigating biogeochemical processes of complex natural samples. However, the conventional methods used to effectively sterilize materials or culture media do not allow sterilizing complex natural samples while maintaining biogeochemical balances. The aim of this study was to develop a low-cost and easy-to-use method to obtain geochemically unmodified and sterilized samples from complex lacustrine or coastal marine ecosystems. In preliminary assays, the impact of several sterilization methods (autoclaving, chemical poisoning, microwave, UV irradiation) on the trace metals balances was studied using borosilicate glass (BG), fluorinated ethylene-propylene (FEP) or polyethylene terephthalate (PET) bottles. Unlike other methods, UV sterilization had minor effects on the distribution of dissolved trace metals. Additional tests using complex lacustrine and coastal marine samples under 10 g/L sediments were performed using a homemade UV sterilization chamber designed to simultaneously irradiate a large number samples. Results showed:•very reproducible UV tests in BG and FEP bottles•faster sterilization using FEP bottles than using BG bottles•low variations of dissolved trace metals concentrations, except for Al, Cu, Fe and Zn

Effect of residual sulfur content on the degradation behavior of cellulose acetate

ABSTRACTFour unplasticized, commercially available cellulose acetate (CA) powders were artificially aged for up to 30 weeks in a humid oven at 70°C and 50% relative humidity (RH) to see if higher levels of residual sulfate groups (−OSO2OH)− attached to the cellulose backbone affected degradation. Qualitative x-ray fluorescence (XRF) of unaged powders showed that three contained the same amount of sulfur while the fourth exhibited more. Three powders were manufactured recently whereas the fourth was produced in the 1970s. Powders were aged in lidded borosilicate glass bottles to impede evaporation of acids generated during artificial aging. A water reservoir was enclosed within each bottle to help maintain humidity. Changes to the level of acidity and sample weight were characterized at various time points. All samples emitted acid vapor with aging yet the powder with higher residual sulfate content emitted the most. Similarly, with aging, only the powder with higher level of sulfur content showed a weight loss. No unique behavior was observed from the powder that had naturally aged for forty years before being artificially aged.

Short-term storage stability of NaOCl solutions when combined with Dual Rinse HEDP.

To assess the stability of NaOCl solutions when combined with a novel product for clinical use, Dual Rinse HEDP, which contains etidronate (1-hydroxyethane 1,1-diphosphonate). Mixtures of NaOCl solutions with Dual Rinse HEDP were prepared so that they initially contained 5.0%, 2.5% or 1.0% NaOCl and always 9.0% of dissolved Dual Rinse HEDP powder per total weight. NaOCl solutions alone were used as controls. The stability of these solutions over 8h was assessed in transparent borosilicate glass bottles at ambient temperature (23°C). Subsequently, the effects of heating (60°C) or storing the solutions at 5°C were studied in polypropylene syringes. NaOCl concentrations were measured by iodometric titration, that is free available chlorine contents. Experiments were performed in triplicate. In the glass bottles at 23°C, the 5.0% NaOCl/9.0% Dual Rinse HEDP solution lost 20% of the available chlorine after 1h, whilst the corresponding 2.5% NaOCl and 1.0% NaOCl solutions retained this relative amount of available chlorine for 2 and 4h, respectively. Results obtained in the glass bottles were similar to those achieved in the syringes. Heating of the NaOCl/Dual Rinse HEDP mixtures had a detrimental effect on available chlorine, with a complete loss after 1h. In contrast, storing the NaOCl/Dual Rinse HEDP mixtures in a refrigerator at 5°C kept the available chlorine high for 7h, with the expected loss after a further hour of storage at 23°C. Initial NaOCl concentration and temperature both affected short-term storage stability of combined solutions containing Dual Rinse HEDP.

The effect of different TiO2 nanoparticles on the release and transformation of mercury in sediment

The environmental safety of both nano-TiO2 particles and mercury (Hg) pollution has been of widespread concern. Soils and sediments were the main receiving environments of nano-TiO2 and Hg. There was a strong association between nano-TiO2 with Hg compounds. Very limited research has been carried out on the impact of nano-TiO2 on the environmental behavior of Hg in sediments. The objective of this study was to investigate the effects of nano-TiO2 on the release and transformation of Hg in sediments. Two types of TiO2 nanoparticles were employed. Sediment samples were collected in the water level fluctuating zone of the Three Gorges Reservoir, China. Sediment samples spiked with HgCl2 solution were taken as Hg-contaminated sediments. The flooding experiments were conducted using capped borosilicate glass bottles containing 300 ml TiO2 suspensions (0.2 g L−1 and 0.4 g L−1) and 30 g original or Hg-contaminated sediment samples outdoors. All experiments were conducted in triplicate. Water samples were collected at determined interval times over a 60-day period. Sediments were collected on the 60th day. Total Hg (THg) and methylmercury (MHg) in both water and sediment samples and Hg speciation just in sediment samples were determined. A series of control samples without TiO2 addition were also prepared. The results showed that nano-TiO2 particles at high content (4 g kg−1) promoted the release of Hg in sediments, and the anatase particles showed a stronger effect. Methyl Hg concentrations in waters of nano-TiO2 treatments significantly decreased by the 10th day. The effect of nano-TiO2 greatly depended on anatase and rutile particles. After that, methyl Hg concentrations had no significant difference between nano-TiO2 treatments and the control, except 2 g kg−1 rutile treatment by the 20th day. The changes of Hg speciation in sediments demonstrated that nano-TiO2 inhibited the transformation of Hg-bound organic matter into the oxidated state, especially upon 2 g kg−1 rutile treatment. This was consistent with the lower MHg concentrations in the 2 g kg−1 rutile treatment. Both anatase and rutile nano-TiO2 were found to affect the release of Hg in sediment. Nano-TiO2 promoted THg release in sediments and posed an increased risk of Hg contamination in waters, especially for anatase particles. Moreover, nano-TiO2 inhibited the methylation process of Hg in sediments at the initial stage of flooding and could affect the transformation of Hg speciation in sediments, especially for low-content rutile particles.

Ultraviolet radiation enhances Arctic net plankton community production

AbstractIn this study we report the response of net community production (NCP) of plankton communities in the Arctic surface waters exposure to natural ultraviolet radiation (UVR) conditions. A possible bias in previous measurements performed using borosilicate glass bottles (opaque to most UVR) can underestimate NCP. Here we show that 77% of the sampled communities suffer, on average, 38.5% of net increase in NCP when exposed to natural UV‐B condition, relative to values when UV‐B radiation is excluded. UV‐B tends to shift communities toward autotrophy, with the most autotrophic communities responding the strongest. This is likely explained by the inhibition of bacterial respiration during the continuous day period of the Arctic summer, corroborated by experiments where bacterial production influenced by UV‐B directly affect NCP. Whereas Arctic warming is expected to lead to lower NCP, our results show that increased UV‐B radiation may partially compensate this negative effect in surface waters.

Assessment of sample storage techniques for total alkalinity and dissolved inorganic carbon in seawater

The borosilicate glass bottle sealed with a ground stopper and vacuum grease is a high quality container for preserving seawater samples for total alkalinity (TA) and dissolved inorganic carbon (DIC); it is recommended in the standard methods, even though this bottle is expensive and hard‐to‐handle. As there is an increased demand for sample storage and transportation by laboratories involved in biological and ocean acidification research, we explore alternative sample storage techniques by testing four types of containers. The results demonstrated that over a period of 47 d, TA values from seawater samples stored in polypropylene (PP) bottles and high density polyethylene (HDPE) bottles were not statistically different from those stored in the benchmark borosilicate glass bottles, both at room and refrigerated temperatures. In addition, DIC concentrations from a seawater sample stored in soda‐lime glass bottles and small volume borosilicate glass vials with screw caps were not statistically different from those stored in the borosilicate glass bottles over at least 148 d. However, the TA value of seawater stored in soda‐lime glass bottles increased significantly with increasing storage time, indicating that this type of soft glass bottle is not suitable for TA sample storage. Therefore, we suggest that PP or HDPE bottles can be used for TA sample storage and small volume borosilicate glass vials with screw caps can be used for DIC sample storage for a period of at least 1.5 months. These storage containers provide economical and easy‐to‐transport alternatives to the recommended high‐quality borosilicate glass bottles.

Short chain regioselectively hydrolyzed scleroglucans induce maturation of porcine dendritic cells

Branched beta-1,3/1,6-glucans (scleroglucan) were produced by cultivation of Sclerotium rolfsii ATCC 15205. Regioselective hydrolysis at the beta-1,3-linkage of the cell-free and purified polysaccharide was performed in borosilicate glass bottles at pH 5, 121 degrees C, and 1 bar for 72 h. The mixture was divided into four molar mass fractions by stepwise cross-flow filtration using different cutoffs. In vitro studies revealed that scleroglucan hydrolysates with a low molar mass of less than 5 kDa significantly stimulated the activation and maturation of porcine monocyte derived dendritic cells (MoDC) by upregulation of CD40 and CD80/86 as well as by reduction of antigen uptake. MoDC treated with low molar mass scleroglucan showed a considerable increase in the amounts of secreted proinflammatory cytokine tumor necrosis factor alpha and stimulated the proliferation of lymphocytes. Therefore, scleroglucan molecules of low molecular weight are able to induce activation and maturation of porcine DC, which are key initiators of inflammatory and adaptive immune responses, and could provide improved protection against infectious diseases.

Effects of reaction mixture and other components on the determination of the equilibrium and rate constants of the hydration reactions of anthocyanins

The equilibrium and rate constants of the hydration and deprotonation reactions of anthocyanins show how their color intensity changes with pH. In the cases of several anthocyanins, the constants for each obtained by several methods are different. In an effort to resolve these discrepancies, we have examined the effects of several components of the pH-jump experiments on the values of the constants. Storage of the buffers to be used in pH-jump experiments in Pyrex or borosilicate glass bottles results in increasing Al 3+ concentration in the buffers over several weeks. When these buffers are used, the anthocyanins with two OH groups on the B ring complex with the Al 3+ which leads to major changes in their spectra, in the equilibrium position, and in the apparent first-order rate constant. Thus, constants determined on the same anthocyanin using the same buffers stored in glass bottles may be different at different times. During the reduction of the experimental data to the rate and equilibrium constants, two divergences from the expected behavior were found. In the calculation K a + K h for the anthocyanin acylated with 4-hydroxy-3,5-dimethoxycinnamic acid (6- O-(4-hydroxy-3,5-dimethoxycinnamoyl)-β- d-glucopyranosyl-(1 → 6)-[β- d-xylopyranosyl-(1 → 2)]-β- d-galactopyranosyl-(1 → O 3)-cyanidin), the plotted points appear to fit two straight lines, intersecting at an equilibrium pH near pH 4. In the calculation which leads to the individual constants of both anthocyanins examined here, the points below an equilibrium pH of pH 4 curve upward from the line that describes the points from an equilibrium pH above 4. Differences in the composition of solutions used in pH-jump experiments examined here, include (1) the addition of phosphate to the acetate buffer, (2) the presence of 0.5 M NaCl, and (3) the solution of the anthocyanin in either 0.1 N HCl or 0.1 N HOAc. These changes gave differences that were statistically significant in some of the constants for each of the two anthocyanins examined. The constants were both qualitatively and quantitatively different.

The Glass Effect in Distillate Fuel Stability

Diesel fuels were stored in glass bottles at 54.4/sup 0/C (130/sup 0/F) or at 98.9/sup 0/C (210/sup 0/F). Some of the bottles were soft glass; some were borosilicate glass. Fuel degradation was measured by the change in light transmission and light scattering and by the amount of insoluble residue and soluble gum formed. Diesel fuel stored in borosilicate glass bottles deteriorated much more rapidly than the same fuel stored in soft glass bottles. Additional experiments showed that soft glass inhibited fuel degradation, while borosilicate glass was essentially inert toward the fuel. The effect of soft glass varied with the fuel. Soft glass greatly improved the stability of some fuels, but had almost no effect on other fuels. Therefore, storage of fuels in soft glass bottles could give misleading results in assessing the relative stabilities of distillate fuels.