nash reagent
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2021 ◽  
Vol 4 (IAHSC) ◽  
pp. 91-99
Author(s):  
Wilis Rarabiella ◽  
Elfira Maya Sari ◽  
Siti Nurfajriah

Introduction: Wet noodles are flour-based foods that are widely consumed by the community because of their easy processing. The high water content in wet noodles makes the noodles not last long. In fact, there is still a preservative in wet noodles that is not used, namely formaldehyde. The purpose of this study was to determine whether there was formaldehyde in unbranded wet noodles in the Traditional Market of South Tambun District and to determine the level of formaldehyde in unbranded noodles in the Traditional Market of South Tambun District. Method: This research was conducted at the STIKes Mitra Keluarga laboratory. The type of research used is descriptive. There are 7 samples taken from 4 different markets. The sample was tested using a formaldehyde test kit and resulted in 6 positive formaldehyde samples. According to SNI, formaldehyde should not be in wet noodles. So that the results of the 6 samples did not meet the quality requirements of wet noodles. Results: Furthermore, the positive sample was determined using a UV-VIS spectrophotometer and Nash reagent. The lowest level of formaldehyde is 18.61 mg/L while the highest level is 738.45 mg/L. Conclusion: First, the regulation is not yet known by the producers because it is classified as traditional. Second, there is no good control from authorized institutions or officers. Third, the lack of guidance for producers


2021 ◽  
Vol 251 ◽  
pp. 02057
Author(s):  
Fenghong Liu ◽  
Xianhao Cheng ◽  
Jing Miu ◽  
Xinjun Li ◽  
Runyang Yin ◽  
...  

The determination of urease activity is one of the important projects in 《Enzyme engineering experiment》 and production. In the paper, the urease activity of soybean was determined by pH increment method, titration method and Nash reagent method, and the three methods were compared. The results showed that the urease activity of the same sample measured by pH increment method, titration method and Nash reagent method was not equal in value and could not be used mutually, and the urease activity of the same sample measured by Nash reagent method was the highest. The same experimental project adopts a variety of methods to improve students ’ interest in learning, improve students’ data analysis ability, and provide a better way to cultivate applied and innovative talents.


2020 ◽  
Vol 4 (2) ◽  
pp. 106
Author(s):  
Wahyu Vera Wardani

Saponin in black tea is predicted having potential to reduce formaldehyde level in preserved fresh tuna (Auxis thazard) using formaldehyde. This research used experimental design, post-test only control group. Variables examined were formaldehyde level, organoleptic values (eye appearance, gill appearance, color, smell, and texture), and soluble protein level. Formaldehyde level was analyzed using Nash reagent by spectrophotometric method. Organoleptic value was conducted using questionnaire by 16 panelists. Soluble protein level was analyzed using Lowry reagent by spectrophotometry. Result showed significant difference between formaldehyde level in control and treatment gorup, but did not significantly difference between formaldehyde level that was immersed in water and black tea solution. Soluble protein level showed no significant difference between samples. There were significant differences in appearance and eye color, while there were no differences in gill appearance, smell and texture. The best treatment was samples immersed in black tea 1,5% for 90 minutes with average levels of formaldehyde 55,76 ug/g, soluble protein content of 0,042 mg/g, eyes appearance 1,59 (slightly white orange), the appearance of gills 2,41 (less crimson), 2,78 body color appearance (slightly orange white), the smell of 2,63 (pungent), the texture of 1,69 (slightly soft). Keyword : black tea, formaldehyde, saponin


PHARMACON ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 556
Author(s):  
Ary Muhatir ◽  
Sri Sudewi ◽  
Henki Rotinsulu

Formalin is a solution which made from 37% formaldehyde in water which is commonly used as preservative for cosmetic products and various types of non-food industrial materials. The use of formalin as a preservative in food is very dangerous for health. The purpose of this study was to determine the presence of formalin found in skewered meatballs circulating in several elementary schools in the city of Manado. Sampling was done in Malalayang Elementary School (A), State Elementary School 6 Manado (B), State Elementary School 9 Manado (C) and State Elementary School 29 Manado (D). In a qualitative test, Nash reagents were used to determine the presence of formalin in the sample. Nash reagent was used to indicate the presence of Formalin content in a sample marked with a change in color to yellow. The results of this study showed that twelve samples of skewers from four elementary schools in Manado City did not contain formalin or safe from formalin use.   Keywords: Formalin, Formaldehyde, Skewered Meatballs, Nash Reagent, Qualitative Analysis  ABSTRAK Formalin merupakan larutan yang dibuat dari 37% formaldehida dalam air yang umumnya digunakan sebagai bahan pengawet produk kosmetik dan berbagai jenis bahan industri non makanan. Penggunaan formalin sebagai bahan pengawet pada makanan sangat berbahaya bagi kesehatan. Tujuan penelitian ini yaitu untuk mengetahui keberadaan formalin yang terdapat pada bakso tusuk yang beredar di beberapa Sekolah Dasar di Kota Manado. Pengambilan sampel dilakukan di SD Negeri Malalayang (A), SD Negeri 6 Manado (B), SD Negeri 9 Manado (C) dan SD Negeri 29 Manado (D).  Pada pengujian kualitatif digunakan pereaksi Nash untuk mengetahui adanya formalin pada sampel. Pereaksi Nash ini digunakan untuk menunjukkan adanya kandungan Formalin pada sampel yang ditandai dengan perubahan warna menjadi kuning. Hasil penelitian ini menunjukkan bahwa dua belas sampel bakso tusuk dari empat Sekolah Dasar di Kota Manado tidak mengandung formalin atau aman dari penggunaan formalin. Kata Kunci: Formalin, Formaldehida, Bakso Tusuk, Pereaksi Nash, Analisis Kualitatif 


2018 ◽  
Vol 3 (2) ◽  
pp. 47-50
Author(s):  
Dwi Wahyuniati ◽  
Cicik Herlina Yulianti ◽  
Mercyska Suryandari

ABSTRAKTisu basah merupakan istilah umum untuk menggambarkan sepotong bahan, umumnya ditambahkan dengan komposisi cairan atau semi cair, dimaksudkan untuk membersihkan dan memberikan rasa lembut. Tisu basah memiliki struktur berserat terdiri dari campuran serat selulosa pulp dan regenerasi, seperti rayon dan atau liosel, dengan atau tanpa serat pengikat. Pada proses produksi, komponen-komponen yang sengaja ditambahkan pada pembuatan tisu basah salah satunya adalah formaldehid sebagai penguat keadaan basah. Akan tetapi penggunaan yang berlebihan dapat menyebabkan ruam pada kulit (dermatitis). Pada penelitian ini dilakukan validasi metode analisis formaldehid pada tisu basah dengan menggunakan metode absorpsi uap SNI ISO 14184-2:2015 dengan pereaksi nash menggunakan spektrofotometri UV-Vis. Sampel yang digunakan adalah tisu basah dari satu merek. Validasi metode dilakukan untuk memastikan metode SNI ISO 14184-2:2015 dapat diterapkan, diperoleh hasil valid, dengan nilai R = 0,9993, yang mendekati nilai 1, menghasilkan persamaan regresi linier y = 0,0294x - 0,0317. Pengujian akurasi diperoleh rata-rata persen recovery sebesar 84,54%, 102,05%, dan 106,13%. Nilai RSD sebesar 1,62%. Hasil nilai LOD sebesar 0,040, sedangkan hasil nilai LOQ sebesar 0,136. Hasil validasi terhadap metode SNI ISO 14184 – 2 : 2015 dapat disimpulkan bahwa metode SNI ISO 14184-2:2015 dapat digunakan untuk menguji formaldehid pada tisu basah. Kata kunci: Validasi, Tisu basah, Formaldehid, Pereaksi Nash, Spektrofotometri UV-Vis.ABSTRACT Wet wipes are the general terms to describe a piece of material, generally impregnated with a liquid or semi liquid composition, intended to both cleaning and providing a smooth feeling. Wet wipes has fibrous structures consist of a mixture of pulp and regenerated cellulose fibers, such as rayon and/or lyocell, with or without binding fibers. In product process, one of components expressly added was formaldehyde as strengthener as wet condition. But, excessive use of formaldehyde can cause skin rash (dermatitis). This study was aimed to Analysis Method Validation of Formaldehyde of Wet Wipes used vapour absorption SNI ISO 14184-2:2015 method with Nash Reagents by UV-Vis Spectrophotometry, and used vapour absorption method. The wet wipes sample used was from one brand. Method validation was conducted to definite SNI ISO 14184-2:2015 method can be applied, the result was valid, r value is 0,9993, the linear regression y = 0,0294x – 0,0317, accuracy percent recovery study showed 84,54%, 102,05%, and 106,13%., Related standar deviation showed 1,62%, limit of detection was 0,040, limit of quantitation was 0,136. The validation result of SNI ISO 14184-2:2015 method can be concluded that SNI ISO 14184-2:2015 method can be applied to examine formaldehid on wet wipes.Keywords: Wet wipes, Formaldehyde, Validation, Nash Reagent, UV-Vis Spectrophotometry.


2017 ◽  
Vol 2 (1) ◽  
pp. 9-16
Author(s):  
Cicik Herlina Yulianti ◽  
Vika Ayu Devianti ◽  
M.A. Hanny Ferry Fernanda

ABSTRAKPembalut menjadi kebutuhan wanita yang sangat penting karena digunakan untuk menyerap cairan darah ketika mengalami menstruasi. Pada pembuatan pembalut wanita dimungkinkan adanya pemakaian formaldehida. Oleh karena itu, pembalut wanita termasuk salah satu alat kesehatan yang kandungan dan bahan penyusunnya diatur oleh pemerintah. Pada penelitian ini menggunakan metode spektrofotometri visibel untuk penentuan kadar formaldehida dalam pembalut wanita sekali pakai. Sebelum digunakan, maka metode spektrofotometri visibel ini harus divalidasi terlebih dahulu untuk memastikan bahwa metode spektrofotometri yang digunakan dapat memberikan hasil yang akurat. Tujuan penelitian ini adalah melakukan validasi metode spektrofotometri visibel untuk penetapan kadar formaldehida dalam pembalut wanita sekali pakai menggunakan pereaksi nash sebagai reagen spesifik. Metode penelitian yang digunakan adalah pembuatan dan pembakuan larutan baku formaldehida, menentukan panjang gelombang maksimal, pembuatan kurva kalibrasi, melakukan uji linieritas, uji LOD dan LOQ, serta uji kesesuaian dan kecermatan, dan menentukan kadar formaldehida pada pembalut wanita. Hasil dari penelitian ini adalah bahwa metode spektrofotometri visibel memiliki selektifitas, linieritas,batas deteksi dan kuantitasi, presisi dan akurasi yang baik. Kadar rata-rata formaldehida pada ke lima sampel pembalut sebesar 2,88 mg/kg - 4,05 mg/kg.Kata kunci: pembalut, formaldehida, validasi, spektrofotometri visibelABSTRACTSanitary napkins are a very important woman’s need to absorb blood fluids when menstruating. In the manufacture of sanitary napkins may contain formaldehyde additives. Therefore, sanitary napkins are one of the medical devices whose composition is regulated by the government. In this study to identify the use of formaldehyde in sanitary napkins was carried out by visible spectrophotometry using nash reagent. This method should be validated in advance to ensure that the method used can provide accurate data. The aim of this research is to validate visible spectrophotometry method for determination of formaldehyde content indisposable sanitary napkins using nash reagent as specific reagent. Validation of UV – Vis spectrophotometry method for determination of formaldehyde showed that Nash reagent was suitable to determine formaldehyde. This method is linear with correlation coefficient (r2) of 0,99967. The validation characteristics include accuracy and precision, linearity, limit of detection, and limit of quantitation. The acceptance validation criteria were found in all case. Qualitative determination in five sanitary napkins samples showed positive results and the quantitative analysis confirmed that the average content of formaldehyde in five sanitary napkins samples was 2,88 mg/kg – 4,05 mg/kg.Keywords: sanitary napkins, formaldehyde, validation, visible spectrophotometry


2015 ◽  
Vol 8 (2) ◽  
pp. 182
Author(s):  
Yulizar Yusuf ◽  
Zamzibar Zuki ◽  
Zamzibar Zuki ◽  
Ruci Riski Amanda ◽  
Ruci Riski Amanda

The case of how handling the fresh fish which used the dangerous chemical material (formaldehyde) is still found in society, so that is why it is necesarry to find the safety way to handle the fresh fish in. It has been held the research about the influence of on the effect of some treatment in reduction the formaldehyde level on fish determined by spectrophotometry UV-Visible at wavelength 412 nm and 40°C. In the preliminary research the fish is soaked in formaldehyde liquid (100 mg/mL) for 24 hours, then washed, soaked and boiled. Then, the filtrate is reacted with Nash reagent. The yellow color which has formed was measured at λ 412 nm. The result shows there is the reduction of formaldehyde level in the sample about 43.9 % after washing, 33.3 % after soaking, 53.8 % after boiling. After that, the fish that was spread in the market which suspected containing the formaldehyde then washed, soaked and boiled. The result shows there is the reduction of formalin level in sample 1 about 22,7 % after washing, 17.0% after soaking, and 96.1 % after boiling. While in sample 2, 41.8 % after washing, 56.2 % after soaking, and 95.4 % after boiling.


2013 ◽  
Vol 341-342 ◽  
pp. 59-63
Author(s):  
Qian Nan Li ◽  
Qiu Hua Yang ◽  
Hai Yun Shen

The nanoKNiF3 with its particles size of 50-70 nm was prepared by solvent-thermal method and characterized by means of XRD, TEM and IR technologies. Photocatalysed reduction of aqueous Na2CO3 was carried out by using nanoKNiF3 powders. Formic acid, formaldehyde and methyl alcohol were identified as photoproducts, and were measured in spectrophotometry using Nash reagent. It shows that nanoKNiF3 has superior photocatalytic activity. Irradiation leads to the production of electrons in the conduction band of the KNiF3 nanoparticles. It is likely that the photoproduced electrons reduce CO32- initially to HCOO-, and then to HCHO and CH3OH.


2011 ◽  
Vol 2 (2) ◽  
Author(s):  
Zilhadia Zilhadia ◽  
Sanny Susanti

Tofu, a food product made from soybean, contain water and it is very easy to overgrown microbes.Based on a survey, many products of tofu contain formaldehyde as preservative. Formaldehyde is apreservative that the use is prohibited for food because it can cause cancer in humans. The aim of thisstudy was determined concentration of formaldehyde in tofu from traditional market Ciputat usingSpectrophotometer UVI-VIS. Steam distillation was used for sample extraction process. Distillate wasreacted with Nash reagent. The equation of calibration curve is y=0,0032x – 0,0079 and correlationcoefficient of the linear regression of 0,9992. The experimental results obtained LOD value of11.1328 μg/ml, LOQ value of 37,1094 μg/mL The precision of this analytical method were lower than2% for each of the sample, while method’s accuration for tofu was 98,69% ± 0,4085%. Results ofsample analysis from Ciputat market, samples were detected containing formaldehyde. Formaldehydeconcentrations are 104,87 μg/mL, 11,21 μg/mL, 1,96 μg/mL, 190,80 μg/mL, 201,98 μg/mL, 10,47μg/mL, and 3,31 μg/mL.


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