Standard Titration Method Research Articles

Environmental assessment of Vaishav stream: a left bank tributary of river Jhelum in Kashmir Himalaya, India

The present study was carried out to assess the environmental impact including water quality parameters of Vaishav stream, one of the left bank tributary of river Jhelum. A detail study of the selected sites was undertaken for the sampling, keeping in mind the topography of the stream i.e. elevations, fast flowing areas, slow zones as well as human interferences. Three sites were selected for study purpose and samples were collected on monthly basis. A total number of 15 parameters were analyzed. Some of the parameters like temperature, pH, TDS, conductivity and 14dissolved oxygen were assessed on spot at sampling sites, while rest of parameters were determined in the laboratory by standard titration methods (APHC 2012). Low DO and higher concentration of pH, CO2, total alkalinity, hardness and nitrate, sulphate, was found at downstream site-III compared to upstream site-I, showing low concentration of these parameters except DO. WQI value varied from 41.50 to177.70 minimum at site-I and maximum at site-III. To quantify the association and co-relationship among various physico-chemical variables, correlation test (Pearson’s correlation coefficient) was carried out. Pearson’s test showed that significant positive correlation exists between pH with total hardness (r= 0.833, p<0.05). The electrical conductivity showed significant positive correlation with TDS (r=1.00, p<0.05), total hardness (r=.897, p<0.05) and sulphate (r=.917, p<0.05). The nitrate shows significant positive correlation with sulphate (r=0.947, p<0.05). The DO shows negative correlation with water temperature (r=-0.396, p<0.05), total alkalinity (r =-0.843, p<0.05) and sulphate (r=-0.902, p<0.05) respectively. Results of ANOVA showed significant level of spatial and temporal variations on the concentrations of water quality parameters (P<0.05, Turkey’s Post Hoc Test) across months at all sampling sites. Therefore, further research is needed to explore the ecological effects of these variations and develop strategies for sustainable water resource management to support ecologists, limnologists, policymakers and other stakeholders in developing long-term management programs and conservation strategies for water resources.

User-friendly diameter-based measurement paper sensor for chloride detection in water

Chloride (Cl−) is an anion widely distributed in nature. It is also an essential parameter to consider when assessing the water quality for ensuring drinking water safety, preventing infrastructure damage, mitigating environmental impact, identifying groundwater contamination. This work presents the first development of a diameter-based measurement paper sensor for chloride analysis using the reaction based on a Mohr's precipitation titration. The paper sensor that has a circular shape with 3-cm diameter was pre-coated with AgNO3 and CrO42− forming brown precipitates of the Ag2CrO4. The sensor was sealed using lamination films with 3-mm diameter hole-punched inlets on the top of the lamination film for sample delivery. To detect chloride, the sensor was simply immersed into the sample. The chloride solution flows into the central sample inlet and spreads radially to undergo the displacement reaction with Ag2CrO4 precipitate, forming AgCl white precipitate whose diameter proportional to the chloride that can be observed within 3 min. Concentration of AgNO3 used was found to impact the analytical figures of merit. The lower AgNO3 concentration yields lower limit of detection, narrower linear range but higher sensitivity. The sensor was applied for chloride analysis in tap water, drinking water and industrial water and the chloride concentration obtained from the developed sensors are not significant differences from those obtained from the standard titration method at 95% confidence interval (two tailed P = 0.08) indicating that the developed sensor provides accurate analysis of chloride in water samples from various sources. The developed sensor was used by the untrained staffs for on-site of analysis chloride in tap water collected at 26 locations in SaenSuk Municipality area, Chonburi, Thailand. The results showed that the chloride level in all samples is in range of 52.2–84.7 mg L−1 which is far below the acceptable range set by the Provincial Waterwork Authority of Thailand (< 250 mg L−1) indicating that the tap water used in this area is safe for consumers.

Diameter-based inkjet-printed paper devices for formaldehyde analysis in foods

In this work, we report a newly developed paper-based analytical device (PAD) for determining formaldehyde in foods. Formaldehyde (FA) is considered as a carcinogen and classified as a Type 2 hazardous substance but it is still illegally use as a preservative in many foods to prevent them from spoilage and increase storage time. Current technologies for quantifying FA in foods are expensive, require long analysis times and skill operators, and are difficult to use on-site with acceptable performance. Consequently, a simple, low-cost, portable, instrument-free measurement test is needed to provide affordable and rapid in-field quantification of FA in foods. The developed FA tests, referred to as the FormaSense™, measure FA by observing diameter of a circular pink ring on the paper that is directly proportional to the FA concentration without the interference of food color background problem hence, increasing the test performance. Printing technologies including wax and inkjet printers were employed to demonstrate highly reproducible and scalable fabrication of the paper-based tests. The results of FA analysis in food samples obtained from the FormaSense™ tests are agreeable with those obtained the standard titration methods with good recoveries in the range of 90–107%. • Diameter-based readout paper devices for formaldehyde (FA) analysis in foods. • FA quantification in foods without interferences from food color background. • Highly scalable production of paper devices using inkjet-printing technology.

Aqueous geochemistry and non-carcinogenic health risk through chloride and nitrate enriched groundwater of cosmopolitan Bangalore city, India

ABSTRACT Industrial pollution in groundwater has become an essential health concern because of its life-threatening health impacts on humans. To examine the hydro-geochemical processes controlling groundwater chemistry in Peenya Industrial Area (PIA), Bangalore city, 65 groundwater samples were collected during July 2016, January 2017, and August 2017 to analyse major ions using Flame-photometer, UV-Spectrophotometer and standard titration methods. The main aim of this study was to categorise the groundwater quality due to improper discharges of industrial effluents (solid and liquid) and the health risk assessment of the local community using this groundwater for daily use. It observes that the nitrate varied from 21 to 461 mg/L (July 2016), 1.01 to 121.7 mg/L (January 2017), and 1.4 to 110 mg/L (August 2017). The maximum samples exceed the threshold values (>45 mg/L). Industrial activities and water–rock interactions are the major factors controlling groundwater chemistry. The pollution risks through the Water Quality Index (WQI), Pollution Index of Groundwater (PIG), Nitrate Pollution Index (NPI), Pollution Loads (%), Revelle Index (RI) and Cumulative Probability (CP) strongly suggest that groundwater in PIA is control of mixing with industrial effluent discharges. Health risk to people through ingestion by computing chronic dose index (CDI), hazardous quotient (HQ), and health-hazardous index (HHI). Most groundwater samples show HHI >1, indicating its unsuitability and causing health effects. The maximum non-carcinogenic risk value for nitrate is 10.31 for adults and 15.07 for children during July 2016; 2.72 for adults and 3.97 for children during January 2017; 2.46 for adults and 3.60 for children during August 2017. Therefore, proper planning for mitigation is required to reduce exposure to save future generations. This study will bring awareness to minimising and treating the groundwater before use.

Assessment of iodine deficiency disorders among pregnant women residing in an urban slum of west Delhi

Iodine deficiency disorders (IDDs) constitute a significant public health problem globally, particularly among pregnant women. This study aimed to assess the prevalence of IDDs among pregnant women during third trimester of pregnancy residing in an urban slum of west Delhi. This was a community based cross sectional observational study conducted on 178 pregnant women from October 2014 to July 2016. Socio demographic information was collected through questionnaire cum interview method. The presence of iodine deficiency disorders was observed through urinary iodine concentration (UIC), thyroid profile, presence of goiter and level of iodization of household salt samples and analyzed respectively using Spectrophotometer, IMMULITE 1000 analyzer, palpation method and standard iodometric titration method. A total of 59.9% pregnant women had insufficient iodine nutrition with the median UIC 132.5 μg/L and interquartile range (IQR) of 145 μg/L. Grade 1 goitre was detected in 2 participants (1.15%) through palpation method. Inadequate iodine content (<15 ppm) was found in 19.8% household salt samples. Results reported the prevalence of hypothyroidism among 27.9% pregnant women. The mean ± SD values of TSH, T4 and T3 were 2.51 ± 1.19 mIU/L, 11.6 ± 2.38 μg/dl and 170.7 ± 41.5 ng/dl respectively. High prevalence of iodine deficiency reflecting low iodine intake along with prevalence of hypothyroidism was recognized among pregnant women residing in slum area of Delhi.

A sustainability study of the processing of kitchen waste as a potential source of biofuel: Biodiesel production from waste cooking oil (WCO)

One of the most concerned components in world’s food system challenges is food waste, and it is particularly a critical issue in developed countries. Waste cooking oil (WCO) is one of the liquid food wastes that are recyclable. A proper recycling practice of WCO helps to reduce the adverse impact on environment and it can be reused by converting it into industrial products such as biodiesel and soap. With the rising in cost of crude oil in the global market and depletion of conventional fuel, the world also is in need of alternative fuel to fulfil the global rising of energy demands. This paper studies on the potential of WCO as a source of biofuel by converting it to biodiesel by transesterification process. The acid value of the WCO is determined using standard titration method, in which, if the percentage of FFA is more than 2%, in which the WCO needs to undergo pre-treatment process. Sodium hydroxide is used as a catalyst and methanol as the reacting alcohol in transesterification. The characteristics of the biodiesel produced were tested and compared with the standard specification of the biodiesel; ASTM D6751 and EN 14214. From the experiment conducted, more than 90% of biodiesel yield can be obtained from the waste cooking oil. The properties of biodiesel that undergoes more washing process, such as acid value, density, kinematic viscosity, and cloud and pour points have values typically close to the ASTM D6751 and EN 14214 biodiesel standards, which can be seen in Sample 1. Producing biodiesel from WCO is one of the alternatives of disposing these waste products as it gives beneficial impacts to the environment. Since WCO is biodegradable, economical, environmental friendly and always available, the economic feasibility of biodiesel production from waste cooking oil is viable.

Determine the iodine content of salt at the household level and its predictors in Bahirdar Town, Northwest Ethiopia.

Introductioniodine deficiency remains a foremost public health problem in developing countries. About 66 million populations were at risk from iodine deficiency, 28 million people suffer from goiter and more than 50,000 prenatal deaths are related to iodine deficiency each year in Ethiopia. Besides, studies from different parts of Ethiopia have shown that a low proportion of households use adequate iodine concentration and varied from one household to another. Despite increased coverage, the quality of available salt is poor. To ensure safe and effective levels of iodine consumption, monitoring the levels of iodine in salt and the iodine status of the population is critical. However, kinds of literature are scant in Ethiopia particularly; no study is conducted in the current study area. Thus, the study aimed to determine the iodine content of salt and associated factors at the household level in Bahir Dar Town, Northwest Ethiopia.Methodsa community based cross-sectional study design was carried out in Bahir Dar Town from September to October 2015. A multi-stage sampling technique was used to select 706 study participants. A pre-tested, structured questionnaire and laboratory were used to collect data. A laboratory test, gold standard iodometric titration method was used to measure individual availability of adequately iodized salt. Multivariable logistic regression analysis was fitted to identify factors associated with the content of iodine. Adjusted Odds Ratio (AOR) with corresponding 95% confidence interval was computed to show the strength of association. In multivariable analysis, a p-value of <0.05 was used to declare statistical significance.Resultsa total, of 690 participants were included in the study. About 70.1% (95%CI: 63.41, 76.76) of the households were used adequate iodized salt (≥15 ppm). The result of the multivariate analysis revealed that respondents with secondary school (AOR=3.05; 95%CI: 1.51,6.18), age 30-44 years (AOR=1.99; 95%CI: 1.08,3.69), good knowledge (AOR=3.34; 95% CI: 2.09,5.32) and being in the highest wealth status (AOR=4.35,95% CI: 2.43,7.8) had higher odds of availability of adequately iodized salt at the household compared to the counterpart. Besides, using covered salt (AOR=6.10, 95% CI: 3.78, 9.87) and storing salt in a dry place (AOR=4.17; 95% CI: 2.21, 7.86) were positively associated with the availability of adequately iodized salt.Conclusionthe availability of adequately iodized salt in the household is still low. Further institutionalizing iodized salt regulation and awareness creation will require to improve safe iodine consumption through the community.

Improving Prediction of Peroxide Value of Edible Oils Using Regularized Regression Models.

We present four unique prediction techniques, combined with multiple data pre-processing methods, utilizing a wide range of both oil types and oil peroxide values (PV) as well as incorporating natural aging for peroxide creation. Samples were PV assayed using a standard starch titration method, AOCS Method Cd 8-53, and used as a verified reference method for PV determination. Near-infrared (NIR) spectra were collected from each sample in two unique optical pathlengths (OPLs), 2 and 24 mm, then fused into a third distinct set. All three sets were used in partial least squares (PLS) regression, ridge regression, LASSO regression, and elastic net regression model calculation. While no individual regression model was established as the best, global models for each regression type and pre-processing method show good agreement between all regression types when performed in their optimal scenarios. Furthermore, small spectral window size boxcar averaging shows prediction accuracy improvements for edible oil PVs. Best-performing models for each regression type are: PLS regression, 25 point boxcar window fused OPL spectral information RMSEP = 2.50; ridge regression, 5 point boxcar window, 24 mm OPL, RMSEP = 2.20; LASSO raw spectral information, 24 mm OPL, RMSEP = 1.80; and elastic net, 10 point boxcar window, 24 mm OPL, RMSEP = 1.91. The results show promising advancements in the development of a full global model for PV determination of edible oils.

Thickening Castor Oil with a Lignin-Enriched Fraction from Sugarcane Bagasse Waste via Epoxidation: A Rheological and Hydrodynamic Approach

Thickening vegetable oils to different extents is of great interest in the design and development of new bio-based lubricant formulations, as achieving a wide range of rheological properties is crucial to the successful replacement of petroleum-based traditional counterparts. With this aim, the influence of epoxidation degree, modified by altering the reaction conditions, on the viscous flow properties of epoxidized castor oil was investigated together with the incorporation of a lignin-enriched fraction from sugarcane bagasse waste to more extensively modify the rheological properties, thereby valorizing this waste fraction. Oil thickening was achieved by promoting the cross-linking between the epoxidized oil and the lignin-enriched fraction that enables the compatibilization of both components. Castor oil epoxidation was assessed by means of standard volumetric titration methods and infrared spectroscopy. In addition, a fully rheological characterization of both epoxidized and lignin-thickened castor oils was carried out. A hydrodynamic approach was also followed, aiming to provide an estimation of the Mark–Houwink–Sakurada parameters and relate the intrinsic viscosity with the average molecular weight of the resulting epoxidized castor oil/lignocellulose macromolecular compounds. The chemical interaction between castor oil and the lignocellulosic material increased as the extent of epoxidation was increased, yielding a variety of rheological responses from Newtonian liquids of increasing viscosities (from around 1 to 500 Pa·s) to viscoelastic liquids.

EVALUATION OF CALCIUM CARBONATE CONTENT IN EGGSHELLS OF AVIAN, TURTLE, SNAIL, AND OSTRICH USING CHEMICAL ANALYSIS AND SCANNING ELECTRON MICROSCOPY

In the present study, different eggs were collected and analyzed from five various animal species: European pond turtle (Emys orbicularis (Linnaeus, 1758)), giant African land snail (Achatina fulica (Bowdich, 1822)), common ostrich (Struthio camelus (Linnaeus, 1758)), white, light-brown, and dark-brown laying hen (Gallus gallus domesticus (Linnaeus, 1758) and European quail (Coturnix coturnix (Linnaeus, 1758). The typical mineral shell mainly composed of the calcite polymorph of CaCO3 but the eggshell consists of membranes, that composed mainly of proteins. The shell quality also could be assigned by several external and internal factors such as oviposition time, animal genotype and age, housing system (for poultry), and mineral nutrition complex. The CaCO3 content was determined by the standard titration method, coz the titration could provide a reliable method for evaluation of CaCO3 content in different types of eggshells. The structural surface characterization of eggshells was performed by scanning electron microscopy (SEM) with a field emission gun. In terms of chemical composition, ostrich eggshells generally did not differ much from those of laying hen, turtles, giant snails, or quail eggs, but the concentration of calcium carbonate was the highest. The average calcium carbonate content of various eggshells is between 84 and 98%. The thickness of the eggshell ranges from 0.08 to 1.89 mm, and it is not the same over the entire surface of the egg. At the sharp end of the egg, the shell is slightly thicker than at the blunt end. The purpose of this study was to study the quantitative content of calcium carbonate in various eggshells of different animals to draw further conclusions in which animals the eggshell contains the maximum amount of biological calcium carbonate.

The Influence of Plasticizers on the Response Characteristics of the Surfactant Sensor for Cationic Surfactant Determination in Disinfectants and Antiseptics.

Surfactant liquid-membrane type sensors are usually made of a PVC, ionophore and a plasticizer. Plasticizers soften the PVC. Due to their lipophilicity, they influence the ion exchange across the membrane, ionophore solubility, membrane resistance and, consequently, the analytical signal. We used the DMI-TPB as an ionophore, six different plasticizers [2-nitrophenyl-octyl-ether (P1), bis(2-ethylhexyl) phthalate (P2), bis(2-ethylhexyl) sebacate (P3), 2-nitrophenyl phenyl ether (P4), dibutyl phthalate (P5) and dibutyl sebacate (P6)] and a PVC to produce ionic surfactant sensors. Sensor formulation with P1 showed the best potentiometric response to four usually used cationic surfactant, with the lowest LOD, 7 × 10−7 M; and potentiometric titration curves with well-defined and sharp inflexion points. The sensor with P6 showed the lowest analytical performances. Surfactant sensor with P1 was selected for quantification of cationic surfactant in model solutions and commercial samples of disinfectants and antiseptics. It showed high accuracy and precision in all determinations, with recovery from 98.2 to 99.6, and good agreement with the results obtained with surfactant sensor used as a referent one, and a standard two-phase titration method. RDS values were lower than 0.5% for all determinations.

Assessment of Iodine in Salt Samples from North Delhi Schools

Iodine is an essential micronutrient required for normal thyroid function, growth, and development. Iodine deficiency can lead to a variety of health and developmental consequences known as Iodine Deficiency Disorders (IDDs). Realizing the magnitude of the problem and to ensure its prevention by 100% consumption of adequately iodized salt (≥15ppm), National Iodine Deficiency Disorders Control Programme (NIDDCP) is being implemented in India. However, periodic assessment of the salt used is needed to ensure the same. Hence, with the objective of assessment of iodine, household salt samples were collected from students of four schools in North Delhi in October 2019. Awareness programme was also planned among the school children in view of Global Iodine Deficiency Disorders Prevention Day. The iodine content of the salt was estimated by standard iodometric titration method. 10 (10.4 %) salt samples were found to have iodine content &lt; 15 ppm. Reasons for low iodine content in the 10 samples need to be assessed along with the information regarding the type of salt used. Measures need to be taken to ensure 100 % consumption of adequately iodized salt (≥ 15 ppm). Also, such periodic assessment should be undertaken to find out the situation in different schools.

Interpreting measurements of total alkalinity in marine and estuarine waters in the presence of proton-binding organic matter

Total alkalinity (AT) is one of four measurable cornerstone parameters for characterizing the marine carbonate system, yet its measurement by standard titration methods is subject to systematic misinterpretations in the presence of uncharacterized dissolved organic molecules in ocean and estuarine waters. A consequence of these misinterpretations may be the lack of thermodynamic consistency that is routinely observed among measured and calculated parameters of the carbonate system. In this work, a numerical model is used to illustrate (a) how proton-binding dissolved organic molecules influence the reported results of total alkalinity titrations in marine and estuarine settings and (b) how errors in interpretations of reported AT values can then propagate through carbonate system calculations, thus distorting biogeochemical interpretations of calculated parameters. We examine five distinct approaches for alkalinity measurement by titration. Ideally, the difference between the measured (reported) AT and the conventional (thermodynamic) definition of inorganic alkalinity (Ainorg) would be zero. However, in the presence of titratable organic matter, our model results show consistent non-zero differences that vary with the chemical properties of the organic matter. For all five titration approaches, the differences between reported AT and Ainorg are greatest when the negative logarithm of the organic acid dissociation constant (pKorg) is between approximately 5 and 7. The differences between reported AT and Ainorg also display previously undescribed variation among measurement approaches, most significantly when pKorg is between approximately 3 and 6 (typical of carboxylic acid groups). The measurement approaches that are most effective at limiting the unfavorable influence of these relatively low-pK organic acids on AT are closed-cell titrations and single-step titrations that are terminated at a relatively high pH. For calculated carbonate system parameters relevant to in situ conditions (e.g., pH, pCO2, calcium carbonate mineral saturation states), errors resulting from the presence of proton-binding organics are largest when calculations are based on the input pair of directly measured dissolved inorganic carbon (CT) and directly measured AT, and can vary in magnitude depending on the titration approach that is used to obtain AT. The modeling results presented in this work emphasize the importance of (a) determining AT in a manner that accounts for the ubiquity of organic alkalinity in marine and estuarine waters and (b) working toward a clearer understanding of the phenomena underlying the routine lack of internal consistency between measured versus calculated carbonate system parameters. Total alkalinity measurements should begin to incorporate either implicit or explicit evaluations of the titration characteristics of the natural organic carbon present in each sample. To that end, we recommend use of secondary titrations to directly measure organic alkalinity (sample-by-sample), characterization of relationships between total dissolved organic carbon concentrations and organic alkalinity (on local to regional scales), and/or exploration of novel curve-fitting procedures to infer the behavior of organic functional groups from titration data.

Quantitative and qualitative assessment on the suitability of seed oil from water plant (Trichilia emetica) for soap making.

Despite widespread and its local available as a naturalized hedge and shade plant, the potential of Trichilia emetica was not utilized in soap making by the majority of local community in various parts of Dodoma, Tanzania. This study aimed to assess the quantity (yields) and quality (Acid Values (AVs), %Free Fatty Acids (%FFAs) and Saponification Values (SVs) of seed oil from water plant (T. emetica), suitable for soap making application. Solvent extraction method was used during oil extraction, where by 50gm of preheated and powdered seed materials were immersed in 250 ml of n-hexane in 1:5 (w/v) to dissolve the oil contained in the seed cake. The oil was collected by vaporizing solvent out through Rotary evaporation at 60 °C. Also standard titration methods were used to obtain SVs, AVs and %FFAs of the extracted oil. Results showed that T. emetica seeds contained higher quantity of oil (48.4%−50.2%) than many reported commercial plant seed oils. Also, the study found higher AV (7.4 mgKOH/g−7.8 mgKOH/g), %FFA (3.7% to 3.9%) and SVs (189.5 mgKOH/g − 191.4 mgKOH/g) than the maximum acceptable limits of 0.50 mg KOH/g, 0.020% and 175 mgKOH/g − 187 mgKOH/g prescribed by ASTM standards (2002). The obtained results showed that, T. emetica seeds yielded high oil quantity with low qualities due to higher levels of acidity. But high SVs guarantees the possibility of using T. emetica seed oil in soap making. However, the oil requires purification in order to bring levels of acidity to acceptable standards and guarantee its normal use in soap making.

A Cross-sectional study assessing the Prevalence ofIodine Deficiency Disorders among school children aged6 to 12 years in Tumakuru district of Karnataka

Background Iodine deficiency disorders IDD constitute a major public health problem in India. Deficiency of iodine can cause physical and mental retardation cretinism abortions stillbirth deaf mutism squint amp various types of goitre. Methodology A community ndash based cross section survey was undertaken during the February-March 2019 in Tumakuru district of Karnataka to find out prevalence of goitre estimate urinary iodine excretion in 6-12 years old school children and household salt iodine concentrations. 2875 school children aged 6-12 years were examined for goitre. Urine samples of 270 childrenwere collected for estimation of urinary iodine using Sandell-Kolthoff method. Household salt samples of the 540 selected children from schools were analyzed for its iodine content by standard iodometric titration method. Results The overall prevalence of Goitre was found to be 9.5 among children examined. The median urinary iodine excretion UIE was 104 mugL. All the household salt samples were adequately iodized having Iodine content of gt15ppm. Conclusion Considering prevalence of goitre in 6-12 years children Tumakuru district is lsquoendemicrsquo for IDD. But as inferred from median UIE obtained IDD is not a public health problem of significance. Household level salt is adequately iodized as per NIDDCP recommendations

Response surface optimization of biodiesel yield from pre-treated waste oil of rendered pork from a food processing industry

In this study, the waste oil of rendered pork (WO-RP) from a food processing industry was studied as a source of biodiesel. The WO-RP was characterized and was found to have a high acid value of 4.30 mg KOH/g. A pre-treatment using H2SO4 was done through the standard titration method that resulted in a reduction of acid value to 0.75 mg KOH/g. The transesterification process over the KOH catalyst was carried out and optimized using the central composite design (CCD) using the Design Expert 7.0 software. The optimum conditions were found at 3:1 methanol–oil molar ratio, 0.55% catalyst loading, and 45-min reaction time. At optimum conditions, the biodiesel yield was 95.28 ± 0.15%. Its chemical characteristics were tested in terms of acid value at 0.75 mg KOH/g, ash content at 0.01 wt%, density at 0.86 g/cm3, HHV at 39.98 MJ/kg, water content at 0.10%, and kinematic viscosity at 6.9 mm2/s. The FAME profile shows the presence of linoleic, palmitic, oleic and stearic acid as major fatty acid components and functional group shows carbonyl group with traces of carboxylic at 1719 cm−1 and the sharp peak of esters at 1749 cm−1 indicating that the derived product is biodiesel.

Rapid detection of infrared inactive sodium chloride content in frozen tuna fish for determining commercial value using short wavelengths

The sodium chloride content in the flesh of tuna fish is one of the factors for determining the price in the fishing industry. Titration is a standard method for the analysis of salt and this is time consuming. Near infrared spectroscopy is a potential alternative method for rapid detection without the need for wet chemical assay. Although sodium chloride is infrared inactive, this study investigated the influence of salt on the absorbance of near infrared energy and showed that the sodium chloride content can be determined using changes in the water band at 970 nm. Calibration equations were developed from frozen fish pieces and ground samples using multiple linear regression for the wavelength region of 700–1000 nm. The best result was achieved from frozen samples with a coefficient of determination for the calibration set ([Formula: see text]) = 0.71, standard error of calibration (SEC) = 0.20%, coefficient of determination for the validation set ([Formula: see text]) = 0.64, standard error of prediction (SEP) = 0.26% and bias = − 0.00%. In order to verify the significant variables used to determine infrared inactive sodium chloride, partial least squares regression was performed on frozen samples. The important variable in multiple linear regression and partial least squares regression was the absorbance band at 976 nm attributed to water molecules. The result from partial least squares calibration showed [Formula: see text] = 0.83, SEC = 0.20%, [Formula: see text] = 0.54, SEP = 0.25% and bias = 0.00%. The salt values predicted using the near infrared models were not significantly different from the reference values obtained by the standard titration method at the 95% confidence interval.

Evaluation of calcium carbonate in eggshells using thermal analysis

The eggshell of the hen is an important structure which provides protection for the developing chick, and also a container for the egg in the food industry. Egg breakage can reach up to 10% of total egg production, causing considerable economic losses. The eggshell consists of membranes, composed mainly of proteins, and the mineral shell composed mainly of the calcite polymorph of CaCO3. The average CaCO3 content of a chicken eggshell is between 93 and 97%, depending on animal genotype, age, housing system of laying hens and mineral nutrition. In the present study, eggs of the same breed and approximately same age were collected from four different production systems: organic farming, free-range production, deep litter system and battery cage system. The CaCO3 content was determined by the standard titration method and by atomic absorption spectroscopy. Thermal properties of dried eggshell powder were measured by thermogravimetric measurements between 30 and 900 °C in air, showing a significant mass loss of ≈ 43% between 600 and 850 °C corresponding to the decomposition of CaCO3 to CaO and CO2. The relations between the thermal mass loss and CaCO3 content determined by the titration method/atomic absorption spectroscopy were studied using predictive models fitted by the linear regression method. A good prediction ability with an average prediction error of 0.01% was obtained between CaCO3 determined by titration and the thermal mass loss, indicating that TG could provide a reliable method for evaluation of CaCO3 content in eggshells.

Variations in Stable Isotopes of Oxygen and Hydrogen in Surface and Groundwater of a Managed Aquifer Recharge Site: A Case Study

ABSTRACT Groundwater storage augmented by Managed Aquifer Recharge methods in a region will help to manage water supply when there is insufficient availability surface water. The present study was carried out to use the stable isotopes of oxygen and hydrogen to study the interaction between the surface and groundwater at Managed Aquifer Recharge (Check dam) site located north of Chennai, Tamil Nadu, India. Water samples from check dam were collected at periodical intervals from October 2011 to April 2012 and groundwater samples from the wells surrounding the dam were collected for the period between January 2012 and July 2012. Electrical conductivity of the water samples was measured using multi parameter probe (YSI 556). Chloride is analysed by standard titration method. δD and δ18O were analysed by PICARRO L1102-i isotope analyser. The variation in isotopic signatures of water from the check dam indicated that water stored in the check dam undergone various degrees of evaporation. The relationship of δ18O with electrical conductivity and chloride of groundwater and water from check dam assisted in delineating the wells recharged from check dam. It is identified, that the wells located 1.5 km surrounding the check dam is benefitted by this structure.

Comparison of Total Inorganic Carbon (TIC) Analysis with Titration Method Analysis in Determining Carbon Dioxide (CO2) Content of Amine Solvent

Total Inorganic Carbon (TIC) is an analysis method to determine carbon content in a sample. In this paper, applicability of TIC method to determine carbon dioxide (CO2) content in amine solvent is explored in detailed. Both commercial and self-blended amine solutions, consisting of MDEA and PZ, were used in this study and bubbled with CO2. TIC method was calibrated for both mid-level mode and high level mode. Difference in results were found when comparing TIC against the standard titration method; this is largely due to error in titration method during the methanol pH adjustment step. TIC method is considered to be better in terms of limit of detection, limit of quantification, recovery percentage, and susceptibility to error.