Smartphone-based colorimetric method for determining sulfites in wine using a universal clamp sample holder and microfluidic cotton swab-based analytical device

2021 ◽  
pp. 107055
Author(s):  
Chutikarn Khamkhajorn ◽  
Somkid Pencharee ◽  
Jaroon Jakmunee ◽  
Napaporn Youngvises
Author(s):  
RIMADANI PRATIWI ◽  
NISA AMALIA ◽  
ALIYA NUR HASANAH

Objective: The aim of this study was to develop Paper-based Analytical Devices (PADs) with colorimetric method as a presumptive test for detecting diazepam in urine Methods: Colorimetric method was used as a principle of this study. PADs were fabricated with wax-printing methods. Chosen colorimetric reagent was tested for selectivity with hydromorphone and codeine; and sensitivity by measuring the absorbance with UV-Vis spectrophotometer. PADs were tested for its sensitivity and stability. The intensity of color developed on PADs are measured with ImageJ. The ability of PADs to detect diazepam in urine was simulated with testing spiked urine sample to the PADs Results: Zimmermann gave the most obvious prominent color change from colorless to purple-red color out of the four reagents. PAD is selective to diazepam when tested with hydromorphone and codeine. PAD is sensitive with a cut-off concentration at 100 ppm. PAD can detect diazepam in urine with the highest recovery percent at 92.8%±4,6 Conclusion: It can be concluded that PAD is quite selective and sensitive to detect diazepam in urine and can be done easily and fast for onsite analysis


Author(s):  
R.C. Dickenson ◽  
K.R. Lawless

In thermal oxidation studies, the structure of the oxide-metal interface and the near-surface region is of great importance. A technique has been developed for constructing cross-sectional samples of oxidized aluminum alloys, which reveal these regions. The specimen preparation procedure is as follows: An ultra-sonic drill is used to cut a 3mm diameter disc from a 1.0mm thick sheet of the material. The disc is mounted on a brass block with low-melting wax, and a 1.0mm hole is drilled in the disc using a #60 drill bit. The drill is positioned so that the edge of the hole is tangent to the center of the disc (Fig. 1) . The disc is removed from the mount and cleaned with acetone to remove any traces of wax. To remove the cold-worked layer from the surface of the hole, the disc is placed in a standard sample holder for a Tenupol electropolisher so that the hole is in the center of the area to be polished.


Author(s):  
Michel Fialin ◽  
Guy Rémond

Oxygen-bearing minerals are generally strong insulators (e.g. silicates), or if not (e.g. transition metal oxides), they are included within a rock matrix which electrically isolates them from the sample holder contacts. In this respect, a thin carbon layer (150 Å in our laboratory) is evaporated on the sections in order to restore the conductivity. For silicates, overestimated oxygen concentrations are usually noted when transition metal oxides are used as standards. These trends corroborate the results of Bastin and Heijligers on MgO, Al2O3 and SiO2. According to our experiments, these errors are independent of the accelerating voltage used (fig.l).Owing to the low density of preexisting defects within the Al2O3 single-crystal, no significant charge buildup occurs under irradiation at low accelerating voltage (< 10keV). As a consequence, neither beam instabilities, due to electrical discharges within the excited volume, nor losses of energy for beam electrons before striking the sample, due to the presence of the electrostatic charge-induced potential, are noted : measurements from both coated and uncoated samples give comparable results which demonstrates that the carbon coating is not the cause of the observed errors.


1999 ◽  
Vol 2 (5) ◽  
pp. 53-54
Author(s):  
D. P. Krowchuk
Keyword(s):  

2017 ◽  
Vol 68 (2) ◽  
pp. 243-245
Author(s):  
Elisabeta Antonescu ◽  
Maria Totan ◽  
Gheorghe Cornel Boitor ◽  
Julianna Szakacs ◽  
Sinziana Calina Silisteanu ◽  
...  

Medical analysis laboratory must establish its own reference intervals depending on the facilities they are working with, the working substances and protocols. These reference intervals must be obtained depending on age groups in order to accurately interpret the results of the analyzes performed. The study is a retrospective one using 3217 data from the electronic archive of the S.C. Vladutiu&Garabedian S.R.L. Clinic in Medias. Total serum calcium was determined by the colorimetric method on the Konelab analyzer. Processing of the collected data was done using the Hoffmann method, considering 5% up to 95% of the values in the database, the values being randomly selected. For comparison, data from the literature was used. In children under 1 year old, it was not possible to calculate the reference intervals since data was insufficient. In the other age groups, reference intervals obtained in the current study were similar to the studied literature. Reference intervals established for calcium can provide important guidance for the reasonable supplementation of this essential element in children.


2020 ◽  
Vol 16 (1) ◽  
pp. 28-33
Author(s):  
Vitalii B. Kaliberdenko ◽  
Shanmugaraj Kulanthaivel ◽  
Michael V. Shterenshis ◽  
Olga Y. Poleshchuk ◽  
Kadri Mametov ◽  
...  

: Bronchial asthma is one of the most common and severe diseases among children. The phenomenon of creatinuria (CU) in patients with bronchial asthma (BA) has been acknowledged for a relatively long time. Aims: The Aim of the research is to study the level of creatinuria, creatinemia, creatine kinase activity, and the concentration of calcium in biological medium (blood, saliva, urine) in children suffering from an intermittent and persistent form of asthma during the period of exacerbation. Material and methods:: The research consists of 102 children with asthma who were treated in inpatient department in Simferopol Clinic. The intermittent course of asthma was recorded in 49 children and a persistent course of asthma was recorded in 53 children. The subject of study was blood serum and daily urine of observed patients. The level of calcium in the biological medium was studied using the "Filisit" test kit (Dnipro) and the activity of the creatine kinase by test set "Lahma". The levels of creatine and creatinine were determined using a colorimetric method based on a color reaction with picric acid. Results and conclusion: : The analysis testifies that creatinuria in children with persistent BA is caused by the disorder of the phosphorylation process rather than the disorder of creatinin rephosphorylation synthesis, that is testified by the normal creatinine level. In children with persistent BA, there is а decrease of creatinine concentration in the blood serum and urine during the exacerbation period and early post exacerbation period. The low activity of creatinine kinase at the background of creatinine elimination is typical for the children in the phase of exacerbation of persistent form of BA, though its level remains to be sufficient for the synthesis of the necessary amount of creatinine phosphate. Conclusion: The processes of creatinuria and calciuria in children suffering from a persistent form of BA are interdependent, that is testified by the data of correlative analysis. In connection with this, it is possible to consider the change of calcium homeostasis in the pathogenesis of the disease as one of the causes of distributing the creatinine metabolism on the cellular level.


Author(s):  
Amit Kumar ◽  
Mahamad Yunus S. Nabooji

Dental caries/Tooth decay is progressive destruction of tooth structure, leading to tooth ache. Tooth ache is the most common type of orofacial pain and when severe it is considered a dental emergency. Pain killers will be the first option to get rid of pain but use of these pain killers have many adverse effects and also its over prescription leads to kidney disorders, liver disorders etc. and in Ayurveda for the management of pain in Krimidanta it is mentioned that, Krimighna (anti-microbial), Vatagna (which relieves Vata) and Ushnaveerya Dravyas (drugs with hot potency) are to be used which can relieve the toothache and discolouration. Hence here an attempt was made to find out an alternate medicine which is effective, has no contraindications and with no side effects. Here the patient was treated with Dantapichu (soaked cotton swab) with Katuparni Ksheera (milk of Argemone Mexicana Linn.) as a local application. After the treatment, a significant response in various symptoms such as tooth pain, tingling sensation and swelling was observed.


1990 ◽  
Vol 10 (1) ◽  
pp. 89-92 ◽  
Author(s):  
Liliane Larpent ◽  
Christian Verger

The fate of the peritoneal membrane on continuous ambulatory peritoneal dialysis (CAPD) is usually evaluated through the modification of its permeability to various solutes as glucose, creatinine, and urea. Therefore, the accuracy of the methods used for measurements of creatinine is of great importance. A particular problem does exist for creatinine determination as it may be influenced by the presence of glucose. We studied a new enzymatic colorimetric method for creatinine determination in peritoneal dialysis solutions which contain high dextrose concentrations. Creatinine was measured in plasma, urine, and dialysate from 18 patients on CAPD and in pure dextrose solutions, with an enzymatic test (Boehringer Mannheim) and with Jaffe's reaction on two different analyzers: Astra (Beckman) and Eris (Merck). Creatinine results were similar with both assays (Jaffe's reaction and enzymatic test) when measured in blood and urine. However the Jaffe's reaction gave higher creatinine results than the enzymatic test (p < 0.001), when assays were performed in peritoneal dialysis solutions and in pure glucose solutions. In addition, it appeared that other components of dialysis solutions, mainly calcium chloride, influenced unpredictably the results of creatinine with the Jaffe's reaction. We conclude that specific enzymatic test is a more accurate and reliable method to evaluate creatinine kinetics through the peritoneal membrane when determined in CAPD solutions.


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