A detailed description editor
Basic Information
Name
English / Latin names
Sodium Pyrosulfite
Jiaoya Liusuanna
English Name
Supplies: http://www.lubonchem.com
: SODIUM BISULFITE; disodiummetabisulfite; disodiumpyrosulphite; fertisilo; metabisulfitedesodium; Sodiummetabisufite; sodiummetabisulfite (na2-s2o5); sodiumpyrosulfite (na2s2o5); Sodium dissulfite; Sodium disulphite; Sodium pyrosulphite; SODIUM METABISULFITE, PH EUR; SODIUM DISULFITE DRY TECHNICAL; SODIUM METABISULFITE ACS REAGENT ;… SODIUM DISULFITE DRY, RG, REAG ACS, REAG PH EUR;. SODIUM METABISULFITE, 97 +%, ACS REAGE NT; SODIUM METABISULFITE 97 +% ACS REAG &; SODIUM METABISULFITE REAGENT GRADE 97%; SodiumMetabisulphiteA.R;. SodiumMetabisulphiteFcc
Chinese alias
Sodium metabisulfite ; dipropylene sulfite ; weight thioredoxin ; pyrogallol sulfite ; sodium metabisulfite ; metabisulfite ; edible metabisulfite .
CASRN :7681-57-4
EINECS No. :231 -673-0
InchI Code : InChI = 1/2Na.H2O5S2/c;; 1-6 ⑵ 5-7 ⑶ 4 / h;; (H, 1,2) (H, 3,4) / q2 * +1 ;/ p-2
Formula : Na2S2O5
Molecular Weight : 190.09
Appearance: white or light yellow crystalline powder or small crystals ..
Specification: ≥ 65% of sulfur dioxide
Iron ≤ 0.005%
Water insoluble ≤ 0.05%
PH value of 4.0-4.6
Chemical Name
Chinese chemical name : sodium metabisulfite
Chemical Name : sodium metabisulfite
Chinese Name 2 : sodium metabisulfite
Name 2: sodium pyrosulfite / sodium metabisulphite
Technical Manual Code : 1333
CAS No. :7681-57-4
Formula : Na2S2O5
Molecular Weight : 190.09
Ingredients and composition
Hazardous components CAS No.
Sodium metabisulfite 7681-57-4
Category : Antioxidants .
Properties and Applications
Summary
Sodium metabisulfite ; sodium metabisulfite ; heavy thioredoxin ; Sodium metabisulfite; Sodium pyrosulfite formula Na2S2O5 Molecular Weight 190.10 CAS No. 7681-57-4
Physical and chemical properties
The main ingredients: pure
Appearance: colorless prismatic crystals or white powder ; has sulfur smell , sour, salty , ; Storage falling yellow color gradient .
pH:
300（fen jie） “>Melting point (℃):> 300 ( decomposition )
Boiling Point (℃): Not available
Relative density ( water = 1 ) : 1.48
Solubility: soluble in water , acidic aqueous solution ( at 20 ℃ to 54g/100ml water ; 100 ℃ when 81.7g/100ml water ) . Soluble in glycerol, slightly soluble in ethanol. The relative density of 1.4 . Soluble in water soluble in glycerine , slightly soluble in ethanol. Damp decomposition, exposed in air easily oxidized sodium . Contact with acid emit sulfur dioxide and generate the corresponding salts. Heated to 150 ℃ decomposition.
Stability and reactivity
Materials to avoid : strong acids, strong oxidizing agents.
Avoid contact conditions : moist air.
Physical and chemical properties
Sodium metabisulfite is white or yellow crystalline powder or small crystals , with a strong smell of SO2 , the proportion of 1.4 , dissolved in water , acidic aqueous solution , with a strong acid contact with the release SO2 and generates the corresponding salts, long home air, the oxidation into Na2S2O6, so the product can not go far. Higher than 150 ℃, namely decomposition SO2.
Security terms
S26In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S39Wear eye / face protection.
Wear goggles or masks.
S46If swallowed, seek medical advice immediately and show this container or label.
If swallowed , seek medical advice immediately and show this container or label.
Risk Phrases
R22Harmful if swallowed.
Harmful if swallowed .
R31Contact with acids liberates toxic gas.
Contact with acids liberates toxic gas.
R41Risk of serious damage to the eyes.
Serious damage to eyes .
Determination
Thiosulfate
Take this product 1.1g, slowly add dilute hydrochloric acid 10ml, dissolved in a water bath for 10 minutes , let cool, relocated colorimetric tube , add water to 20ml, as was muddy , and sodium thiosulfate solution ( 0.1 control solution mol / L) 0.20ml comparison is made using the same method , no thicker ( 0.2% ) .
Iron
Take this product 1.0g, 5ml of water and hydrochloric acid 2ml dissolved , evaporated on a water bath , the residue with water 15ml 2ml hydrochloric acid , dissolved , add the amount of bromine test solution and the solution of microscopic yellow , heated to remove excess bromine , let cool , add water to 25ml, according to inspection , 2.0ml solution compared with standard control solution made of iron , not deeper ( 0.002% ) .
Heavy Metal
Take this product 1.0g, 10ml water dissolved, add 5ml of hydrochloric acid , evaporated on a water bath , the residue water 15ml, slowly boil for 2 minutes, filtered , and the filtrate was added so that the amount of bromine test solution clarified , heated to remove excess bromine , let cool, add 1 drop of phenolphthalein indicator solution and the amount of ammonia solution until the solution was pink , vinegar salt buffer (pH3.5) 2ml with water to make a 25ml, according to inspection , containing no heavy metals per million dated .
Arsenic
Take this product 1.0g, 4ml dissolved add water, add 3ml of nitric acid , evaporated on a water bath , the residue was added a few milliliters of water , stir, filter , filter residue washed with water , lotion combined with the filtrate evaporated , add 5ml of hydrochloric acid water 23ml, dissolved, according to inspection shall comply with the provisions of ( 0.0002% ) .
Production
[ 4 ] metabisulfite production process route has two dry and wet .
( 1 ) dry . Soda ash and water in a molar ratio Stir Na2CO3.nH2O be generated in blocks when placed in the reactor to maintain a certain gap between the blocks and then pass into SO2, until the reaction is complete, remove lumps , after crushing finished.
( 2 ) a wet method. In the solution of sodium hydrogen sulfite in the added amount of soda ash, sodium sulfite to generate a suspension , and then pass into SO2, which generates crystalline sodium metabisulfite , centrifugal separation , drying derived products .
Project Wet Dry
High intensity mechanized production process cumbersome process
The purity of the end product quality, high-purity
Lower consumption of raw materials
Higher
1 , the principle of wet production
[ 5 ] Law of production of sodium metabisulfite reaction process in four steps :
( 1 ) in sodium carbonate solution leads to p H 4.1 SO2 produce sodium bisulfite solution , reaction is as follows :
Na2CO3 +2 SO2 + H2O eleven 2NaHSO3 + CO2
( 2 ) a solution of sodium hydrogen carbonate was adjusted to p H plus 7-8 , i.e. converted to sulfite, the reaction is:
NaCO3 + 2NaHSO3-2Na2SO3 + CO2 + H2O
( 3 ) by reaction with sodium sulfite SO2 to p H of 4.1 , and generate sodium bisulfite solution , the reaction is :
Na2SO3 + SO2 + H2O a 2NaHSO3
( 4 ) When the content of sodium sulfite solution reached saturation concentration , the precipitated crystals of sodium metabisulfite , and the reaction formula:
2 NaHSO3 a Na2S2O5 + H2O
This four -step reaction overall reaction is:
Na2CO3 +2 SO2 a Na2S2O5 + CO2
But if the reaction conditions are inappropriate , but also produce the following side effects :
2 Na2CO3 +3 SO2 a Na2S2O5 + Na2SO3 ten 2CO2
2 , sulfur as raw wet traditional craft
First sulfur pulverized into powder , compressed air get eight burning furnace , autoignition at 600 ~ 800 ℃, the air is added in an amount of about 2 times the theoretical amount , the gas concentration of 10 to 13 SO , dust removal and filtration after cooling sublimation of sulfur and other impurities , and the gas temperature is reduced to about 0 ℃, passed through a series of reactors
The third stage of the reactor was slowly added and the reaction carried out in the mother liquor and the aqueous soda solution secluded . The reaction is as follows :
2NaHSOJ + Na: CO3-2 Na z SOa + CO: + H z O
Suspension of sodium sulfite are sequentially generated by the second stage , a first stage reactor , and SO absorption reaction of sodium metabisulfite Results
Crystal .
The main purpose
Chemical industry
For the production of sodium hydrosulfite , sulfamethazine dipyrone, caprolactam and purification chloroform, benzene and formaldehyde solasulfone . Photographic industry as ingredients fixer . Perfume industry for the production of vanillin . Used as a preservative brewing industry , rubber coagulant and after bleaching cotton antichlor . Organic intermediates , dyes, tanning as a reducing agent is used in electroplating industry , wastewater treatment and as a mine field dressing agent.
Industry
On for dyeing, organic synthesis , printing , leather , pharmaceutical and other sectors ; as a preservative , bleach, bulking agent in food processing .
Used as a chemical reagent
( Printing and photography , etc. ) , used as a bleaching agent, mordant, reducing rubber coagulant, also used in organic synthesis pharmaceutical and spices.
Packing and storage
Storage of
Storage and validity : shading, sealed and stored.
Packaging matters
Lined with polyethylene plastic bags, plastic woven bag, net weight 25kg or 50kg. It should be stored in a cool, dry place . Packing seal , should prevent air oxidation . Pay attention to moisture . Transport should be protected against rain and sun exposure. Is strictly prohibited and acids , oxidants and harmful toxic substances during storage or shipment . The product should not be stored for long time . When working gently to prevent rupture of the package . When fire, water and a variety of fire extinguishers to fight the blaze .
1 . Bags ( barrel ) should be painted a solid logo , including : name , grade, weight and production plant name ;
2 . Sodium metabisulfite plastic bags or drums lined with plastic bag , net weight 25 or 50kg;
3 . This product transportation, storage should prevent damage, moisture , heat deterioration. Prohibited with oxidants , acids coexist ;
4 . The product from the date of manufacture , storage period of six months.
Packing: 25 kg net weight 1100 kg plastic woven bag or net bag material .
Packaging Category : Z01
Transport matters
When packaging to shipment , loading should be safe. During transport to ensure that the container does not leak, did not fall, do not fall, no damage . Non- oxidants, acids , food chemicals mixed mixed operation . Transit should prevent exposure, rain, anti-high temperature . Transport vehicles should be thoroughly cleaned completed .
Question
The main hazards
Health hazards: The product on the skin , mucous membranes significantly stimulated, can cause conjunctiva , bronchitis symptoms. People with allergies or asthma , are very sensitive . Direct skin contact can cause burns.
Explosion hazard: The product is flammable , toxic , irritating.
Security terms
S26In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S39Wear eye / face protection.
Wear goggles or masks.
S46If swallowed, seek medical advice immediately and show this container or label.
If swallowed , seek medical advice immediately and show this container or label.
Risk Phrases
R22Harmful if swallowed.
Harmful if swallowed .
R31Contact with acids liberates toxic gas.
Contact with acids liberates toxic gas.
R41Risk of serious damage to the eyes.
Serious damage to eyes .
Treatment measures
First aid measures
Skin contact : Immediately remove contaminated clothing , rinse for at least 15 minutes with plenty of water . Doctor.
Eye contact: immediately filed eyelid , with a large number of mobile water or saline thoroughly washed at least 15 minutes . Doctor.
Inhalation: from the scene to fresh air. If breathing is difficult , give oxygen. Doctor.
Ingestion: water were found to blues or egg white . Doctor.
Fire-fighting measures
Hazardous characteristics : a strong reduction . With strong oxidizing agents such as chromic anhydride, chlorate and potassium permanganate , strong reactions can occur , causing a fire or explosion .
Hazardous combustion products: sodium oxide (Na2O) and sulfur dioxide (SO2)
Burning Formula : Na2S2O5 + O2 == lit == 2SO2 + Na2O
Fire fighting methods : firefighters must wear fire protective body suits , fire in the wind . Possible to move containers from the scene empty Department during the fire.
3 spill response
Emergency treatment: isolation leak contaminated areas, restricting access. Recommended emergency personnel wearing a dust mask ( full cover ) , wear protective clothing. To avoid dust, carefully scan, bag placed transfer to a safe place . If large spills, using plastic sheeting, canvas cover . Recycling or collection shipped to the waste disposal sites.
2 Edit the contact protection
Exposure controls and personal protection
Occupational Exposure Limits
TLVTN: 5mg/m3
Engineering controls : closed production process to enhance ventilation .
Respiratory protection : air concentrations exceeding the dust , wear self-absorption filter respirators . Emergency rescue or evacuation, air respirators should be worn .
Eye protection : Wear protective chemical safety glasses.
Physical protection: wear protective overalls on infiltration .
Hand Protection: Wear rubber gloves.
Other protection: timely change of clothes. Maintain good health habits .
Waste disposal
Waste Disposal Method : Disposal should refer to national and local regulations. After neutralization , landfill disposal Safety Act .
Regulatory Information
Regulatory Information Chemical Dangerous Goods Safety Management Regulations ( February 17, 1987 the State Council) , the implementation of Chemical Dangerous Goods Safety Management Regulations and Rules ( Labor Fa [ 1992 ] No. 677 ) , the workplace safe use of chemicals ( [ 1996 ] labor Department No. 423 ) and other regulations for the safe use of hazardous chemicals , production, storage , transport, handling , etc. are made as appropriate.
3 Determination editor
Principle of the method
Method name: sodium metabisulfite — Determination — metabisulfite redox titration
Applications: The method of determination of sodium metabisulfite using the titration method .
The method is applicable to sodium metabisulfite .
Test set iodine bottle , precision iodine titration solution (0.05 mol / L) 50mL, Mesa, and shake to dissolve , add hydrochloric acid 1mL, with sodium thiosulfate solution (0.1 mol / L) titration , near the end when starch indicator solution 1mL, continue titration until the blue disappears , calculate the content of sodium metabisulfite .
Reagents: 1 iodine titration solution (0.05mol / L).
⒉ sodium thiosulfate solution (0.1 mol / L)
⒊ starch indicator solution
⒋ hydrochloric acid
Equipment
Sample Preparation: 1 iodine titration solution (0.05mol / L)
Preparation : Take iodine 13.0g, 36g and after adding potassium iodide dissolved in 50mL water , add 3 drops of hydrochloric acid and water to make into 1000mL, shake , filtration using a sintered glass filter .
Calibration: C drying to constant weight at 105 º benchmark of arsenic trioxide approximately 0.15g, plus sodium hydroxide solution (1mol / L) 10mL, micro heat to dissolve, add 20mL of water and 1 drop of methyl orange indicator solution , sulfuric acid titration solution (0.5mol / L) the amount of the yellow to pink , plus sodium bicarbonate 2g, water and starch indicator solution 50mL 2mL, using the droplet to the solution was bluish purple. Each 1mL iodine titration solution (0.05mol / L) is equivalent to 4.946 trioxide . Take the amount of the solution according to consumption and arsenic trioxide , calculate the concentration of the solution, that is, too .
For when titration with iodine solution (0.025mol / L), the desirability of iodine titration solution (0.05mol / L) diluted with water made .
Storage: glass-stoppered brown glass bottles , sealed and stored in a cool place .
⒉ sodium thiosulfate solution (0.1 mol / L)
Preparation: 26g anhydrous sodium thiosulfate 0.20g, add boiling over cold water amount to dissolve into 1000mL, shake , place one month after filtration.
Calibration: drying to constant weight at 120 ℃ baseline potassium dichromate about 0.15g, accurately weighed, set the iodine bottle , add water to dissolve 50mL , add potassium iodide 2.0g, gently shake to dissolve , add dilute sulfuric acid 40mL, shake , Mesa ; in the dark for 10 minutes, diluted with water 250mL , using the droplet to near the end , add the starch indicator solution 3mL, continue titration to the disappearance of visible light green blue and titration with blank test correction. Each 1mL sodium thiosulfate (0.1mol / L) is equivalent to 4.903g of potassium dichromate . According to the amount of consumption of the liquid taken with potassium dichromate , calculate the concentration of the solution, that is, too .
Room temperature over 25 ℃ , the reaction mixture should be cooled and diluted with water to about 20 ℃.
⒊ starch indicator solution
Take soluble starch 0.5g, add water , stir 5mL , slowly pour boiling water into the 100mL , with the added with stirring and continue to boil for 2 minutes , let cool , pour the supernatant , ie. The solution should be Pro with the new .
4 steps to edit
Principle
Take iodine test solution , the amount of aqueous solution of the product , the color of iodine will disappear ; identification solution was obtained by the reaction of sulfate . 2 ) The product is significant sodium flame reaction .
Summary
Take the product of about 0.15g, accurately weighed, set iodine flask, precision iodine titration solution (0.1mol / L) 50ml, Mesa , dissolved , add hydrochloric acid 1ml, titrated with sodium thiosulfate solution (0.1mol / L) titration , until near the end , add the starch indicator solution 2ml, continue to titrate to disappearance of the blue ; and titration of the blank correction. Each 1ml iodine titration solution (0.1mol / L) is equivalent to 4.752mg of Na2S2O5.
Detailed
Thiosulfate take this product 1.1g, slowly add dilute hydrochloric acid 10ml, dissolved in a water bath for 10 minutes , let cool, relocated colorimetric tube , add water to 20ml, as was muddy , and sodium thiosulfate titration solution (0.1mol / L) compare 0.20ml made using the same method control solution , not thicker ( 0.2% ) . Iron to take the goods 1.0g, 5ml of water and hydrochloric acid 2ml dissolved, evaporated on a water bath set , residue, water and hydrochloric acid 15ml 2ml, dissolved , add the amount of bromine test solution and the solution of microscopic yellow , heated to remove excess bromine, let cool , add water to 25ml, according to inspection ( Appendix Ⅷ G), and compare and contrast the standard iron solution 2.0ml solution made no deeper ( 0.002% ) . Heavy metals in the product 1.0g, 10ml water dissolved, add 5ml hydrochloric acid on a water bath evaporated and the residue was added water 15ml, slowly boil for 2 minutes, filtered , and the filtrate was added so that the amount of bromine test solution clarified to remove excess heat bromine, let cool, add 1 drop of phenolphthalein indicator solution and the amount of ammonia solution until the solution was pink , vinegar salt buffer (pH3.5) 2ml with water to make a 25ml, according to inspection ( Appendix Ⅷ H first Law ) , containing heavy metals must not exceed twenty millionths . Arsenic take this product 1.0g, 4ml dissolved add water, add 3ml of nitric acid , evaporated on a water bath , the residue was added a few milliliters of water , stir, filter , filter residue washed with water , lotion combined with the filtrate evaporated, add 5ml of hydrochloric acid and water, 23ml, after dissolution , according to inspection ( Appendix Ⅷ J first law ) , shall comply with the provisions of ( 0.0002% ) .
Take the product of about 0.15g, accurately weighed, set the iodine bottle , precision iodine titration solution (0.05 mol / L) 50mL, Mesa, and shake to dissolve , add hydrochloric acid 1mL, with sodium thiosulfate solution ( 0.1 mol / L) titration , add starch indicator solution 1mL near the end , continue titration to the disappearance of the blue and titration results of the calibration blank test . Each 1mL iodine titration solution (0.05 mol / L) is equivalent to 4.752mg of Na2S2O5.
Note: ” Precision Weigh ” means to check the weight should be accurately referred to take the weight of one-thousandth .
References: People’s Republic of China , the State Pharmacopoeia Commission Code , Chemical Industry Press , 2005 edition, two , p914.
5 effects editor
Use a
Used as a bleaching agent , mordant , reductant , rubber coagulant, also used in organic synthesis , pharmaceutical and spices.
Uses two
Chromatography analysis reagents, preservatives and reducing agents, dyes and pharmaceutical industries for
Uses three
Shakespeare sulfate sodium metabisulfite more intense reduction, similar to the role and sodium sulfite . China provides for preserves, biscuits, sugar , sugar , caramel , candy , glucose, liquid glucose, bamboo shoots , mushrooms and canned mushrooms , maximum use of 0.45g/kg. Candied fruit , bamboo shoots, mushrooms and canned mushrooms , residue and blackcurrant juice grapes (in SO2 dollars ) less than 0.05g/kg; residues of biscuits , sugar , noodles and other varieties of less than 0.1g/kg; liquid glucose residues amount of not more than 0.2g/kg.
Uses four
Four food industry as a bleaching agent , preservative, osteoporosis agents, anti -oxidants , color agents and preservatives .
Use five
Pharmaceutical industry for the production of chloroform, benzene and formaldehyde solasulfone . Rubber industry as a coagulant. Bleached cotton dyeing industry as dechlorination agent, cotton scouring additives. Treatment for leather tanning industry , make the leather soft , plump , tough , waterproof, bending, wear-resistant properties . Chemical industry for the production of hydroxy vanillin, hydroxylamine hydrochloride . Photographic industry as a developer and so on.
Uses six
Analysis. Preservative . Reductant. Antioxidants
6 illegal use of editing
Case law
Free preservative manufacturers add bleach candied
CCTV reported the Hangzhou section preserves manufacturers, workers are free to add additives, counterfeit detection reports. After testing, the number of varieties of candied fruit contains sodium cyclamate , sodium saccharin and other sweeteners , carmine , amaranth , bright blue coloring agent and as a bleaching agent and preservative sulfur dioxide in excess of the maximum use of national standards amount .
Sodium metabisulfite , which acts as a bleaching and antiseptic . In accordance with national standards , preserves the processing can limit the use of sodium metabisulphite as a bleaching agent , but in some plants, for the use of sodium metabisulfite , but it is by geographical added .
Experts said that if the excess consumption of ultra- long range , it may cause liver , kidney, add some burden , some sensitive people , maybe there are some hazards, such hazards may exist. [ 6 ]
Ramen illegal additives
The product is often used as a ramen drawn additives, used to change the structure of the surface , making ramen easily molded .
In the fight against illegal food additives special rectification , the health department found that minority businesses add sodium metabisulfite in flour products , for which the Ministry of Health to make a clear reply : ” food additives health standards ” (GB2760) in sodium metabisulfite range does not include surface products , the use of sodium metabisulfite in flour products is illegal , it should be severely punished according to law .
National Standards
1980s, the country had developed a more lenient standard , that is the amount of sulfur dioxide can reach 2% in 2003 , when the national standards for a change , it changed into 0.05% , but many companies can not do this , because If we do not add so much sodium metabisulfite , then finally it is perishable , moldy , it must be added that much. Later, after coordination , and finally became 0.35% , but 0.35% of this standard, many companies are not up .
7 Storage features editor
Handling Precautions
Closed operation, enhance ventilation . The operator must go through specialized training , strict adherence to rules . Proposed operators wear self-absorption filter respirators , wearing chemical protective safety glasses , wear protective overalls on infiltration , wear rubber gloves. Avoid generating dust . Avoid contact with oxidizing agents , acids touch. Handling of light when light unloading , packaging and containers to prevent damage . Equipped with spill response equipment . Empty containers may be harmful residues .
Storage Precautions
Store in a cool , dry , well-ventilated warehouse. Keep away from fire and heat. Keep container tightly closed . Should oxidants , acids, food chemicals stored separately and avoid mixing reservoir. Should not go far , so bad. Storage areas should be equipped with suitable material spill .