Nitric oxide (tsis muaj) yog cov roj tseem ceeb siv thoob plaws ntau yam, los ntawm kev kho mob mus rau kev tsim khoom thiab kev tshawb fawb tshuaj. Txawm li cas los xij, cov khoom lag luam muaj nitric oxide feem ntau muaj cov impurities, tshwj xeeb tshaj yog nitrogen dioxide (NO₂), uas yog tshuaj lom heev thiab tuaj yeem cuam tshuam rau cov kev xav tau. Yog li, paub yuav ua li cas ntxuav nitric oxide kom zoo yog qhov tseem ceeb rau kev ua kom muaj kev nyab xeeb thiab ua tau zoo hauv nws txoj kev siv.

Cov lus qhia dav dav no yuav tshawb txog ntau txoj hauv kev rau purifying nitric oxide, qhov tseem ceeb ntawm kev tshem tawm cov impurities tshwj xeeb, thiab cov kev coj ua zoo tshaj plaws rau kev siv cov pa roj reactive.

Nkag siab Nitric Oxide thiab nws cov impurities

Nitric oxide yog cov pa roj uas tsis muaj xim uas ua raws li cov cim tseem ceeb hauv cov kab ke lom neeg thiab ua haujlwm tseem ceeb hauv kev lag luam tshuaj. Qhov kev sib tw tseem ceeb hauv kev siv NO yog nws qhov kev ua haujlwm siab, tshwj xeeb nrog oxygen.

Teeb meem nrog Oxygen

Thaum nitric oxide raug rau oxygen, nws sai sai oxidizes los tsim nitrogen dioxide (NO₂):

Nitrogen dioxide yog xim liab-xim av, muaj kuab lom heev uas tuaj yeem ua rau ua pa nyuaj yog tias nqus tau. Hauv kev siv tshuaj kho mob, xws li nqus tau nitric oxide (iNO) kho rau pulmonary hypertension, muaj NO.₂ yuav tsum nruj me ntsis txo kom tsis txhob mob ntsws.

Common impurities

Dhau li NO₂, lwm yam impurities pom nyob rau hauv unpurified nitric oxide muaj xws li:

• Dinitrogen trioxide (N₂O₃): Tsim los ntawm cov tshuaj tiv thaiv NO thiab NO₂.
• Dinitrogen tetroxide (N₂O₄): Lub dimer ntawm NO₂.
• Nitrous oxide (N₂O): Muaj peev xwm tam sim no nyob ntawm txoj kev tsim khoom.
• Moisture (H₂O): Muaj peev xwm teb tau nrog NO₂ los tsim nitric acid (HNO₃).

Cov txheej txheem rau Purifying Nitric Oxide

Kev ua kom huv ntawm nitric oxide feem ntau tsom rau kev tshem tawm nitrogen dioxide thiab ya raws. Muaj ntau txoj hauv kev tuaj yeem ua haujlwm, xws li los ntawm kev sim yooj yim teeb tsa mus rau cov txheej txheem kev lag luam.

1. Tshuaj txhuam hniav

Tshuaj txhuam hniav yog ib txoj hauv kev zoo tshaj plaws rau kev tshem tawm NO₂ los ntawm NO gas ntws. Qhov no suav nrog kev hla cov pa roj tsis huv los ntawm cov khoom siv los yog kua nruab nrab uas ua rau cov tshuaj tsis huv.

Khoom Sorbents

Cov khoom sorbents nquag siv vim lawv yooj yim thiab ua tau zoo. Lawv lub cev los yog tshuaj khi cov impurities.

• Soda txiv qaub: Kev sib xyaw ntawm sodium hydroxide (NaOH) thiab calcium hydroxide (Ca(OH))₂). Soda txiv qaub reacts nrog NO₂ thiab tej yam acidic gases tam sim no, neutralizing lawv.
  
  Teb: 2 NO₂ + 2 NaOH → NaNO₂ + NOV₃ + H₂O
• Ascarite (Sodium Hydroxide ntawm Asbestos / Silica): Zoo ib yam li dej qab zib txiv qaub, nws muab thaj chaw siab rau cov tshuaj tiv thaiv neutralization.
• Cov pa roj carbon activated: Yuav adsorb NO₂ thiab lwm yam tsis huv, txawm hais tias nws yuav xav tau kev kho mob tshwj xeeb los txhim kho nws cov kev xaiv rau NO₂ dhau NO.

Liquid Scrubbers

Kev ua kua dej yog bubbling cov roj sib tov los ntawm cov tshuaj reactive.

• Alkaline Solutions: Dhau cov roj los ntawm cov ntsiab lus aqueous ntawm sodium hydroxide (NaOH) lossis potassium hydroxide (KOH) zoo tshem tawm NO.₂ los ntawm kev tsim nitrites thiab nitrates.
• Sodium Dithionite (Na₂S₂O₄) Kev daws teeb meem: Qee zaum siv rau hauv cov ntawv tshwj xeeb los txo cov oxides ntau dua ntawm nitrogen rov qab mus rau NO lossis rau ntau cov ntaub ntawv soluble.

2. Cold Traping (Cryogenic Purification)

Txias ntxiab siv qhov sib txawv ntawm qhov kub thiab txias ntawm nitric oxide thiab nws cov impurities cais lawv.

• Nitric Oxide (NO): Kub taw tes = -152 ° C, Melting point = -164 ° C
• Nitrogen Dioxide (NO₂): Kub taw tes = 21 ° C, Melting point = -11.2 ° C
• Dinitrogen Tetroxide (N₂O₄): Cov ntaub ntawv yooj yim ntawm qhov kub thiab txias los ntawm NO₂.

Tus txheej txheem:

1. Cov roj sib tov tsis huv yog dhau los ntawm cov cuab yeej txias (piv txwv li, U-tube lossis cov condenser tshwj xeeb) submerged hauv da dej txias.
2. Cov dej khov qhuav / acetone da dej (-78 ° C) los yog cov kua nitrogen da dej (-196 ° C) tuaj yeem siv.
3. Ntawm qhov kub thiab txias no, NO₂ thiab N₂O₄ yuav condense thiab khov nyob rau hauv lub ntxiab, thaum lub volatile NO gas dhau los.

* Ceeb toom: ceev faj heev yuav tsum tau siv nrog cryogenic purification kom lub cev tsis muaj oxygen, raws li condensing kua oxygen nyob rau hauv lub xub ntiag ntawm reactive gases yog heev tawg.*

3. Permeation thiab Membrane Separation

Rau cov ntawv thov tshwj xeeb, tshwj xeeb tshaj yog qhov kev xa khoom tsis tu ncua ntawm NO yog qhov yuav tsum tau ua, cov txheej txheem membrane tau ua haujlwm. Cov daim nyias nyias nyias tso cai tsis pub nkag mus thaum thaiv qhov loj lossis ntau dua polar molecules zoo li TSIS₂. Cov thev naus laus zis no qee zaum koom ua ke rau hauv cov txheej txheem kho mob niaj hnub no kom paub meej lub sijhawm ua kom huv si ua ntej tus neeg mob nqus pa.

4. Advanced Sorbent Materials

Kev tshawb fawb tsis ntev los no tau tsom mus rau kev tsim cov khoom siv siab heev rau kev xaiv NO₂ tshem tawm. Hlau-Organic Frameworks (MOFs) thiab cov zeolites tshwj xeeb raug tshawb xyuas rau lawv lub peev xwm siab thiab tshwj xeeb hauv kev ntxiab NO₂ molecules thaum tso cai NO kom dhau mus dawb. Cov ntaub ntawv no muab lub peev xwm rau kev ua kom huv huv hauv lub neej yav tom ntej.

Pom zoo kuaj teeb rau NO Purification

Rau kev siv hauv chav kuaj qhov twg siab purity ntawm NO yog yuav tsum tau, ib tug sequential purification tsheb ciav hlau yog feem ntau txhim khu kev qha txoj kev.

Tsheb ciav hlau Purification

Ib qho kev teeb tsa hauv chav kuaj yuav suav nrog cov theem hauv qab no hauv koob:

Kev ua haujlwm zoo tshaj plaws

1. Ib puag ncig Anaerobic: Tag nrho cov purification system yuav tsum nruj me ntsis purged nrog ib tug inert roj (zoo li Nitrogen los yog Argon) ua ntej qhia NO. Txawm tias cov pa oxygen yuav rov tsim dua tam sim no NO₂.
2. Monitor Breakthrough: Khoom sorbents muaj peev xwm ua tiav. Ntau yam, zoo li qee hom dej qab zib txiv qaub los yog Drierite, muaj cov cim xim uas qhia tau tias lawv saturated. Ib txwm saib xyuas cov kab thiab hloov cov xov xwm ua ntej kev tawg tshwm sim.
3. Flow Control: Tus nqi ntws ntawm cov roj los ntawm lub tsheb ciav hlau purification yuav tsum tau tswj. Yog tias qhov ntws nrawm dhau lawm, cov roj yuav tsis muaj lub sijhawm sib cuag txaus nrog cov sorbents lossis cov cuab yeej txias kom ua tiav tag nrho cov purification.
4. Khoom siv Compatibility: Xyuas kom tag nrho cov tubing, fittings, thiab li qub yog sib xws nrog TSIS MUAJ thiab TSIS TAU₂. Stainless hlau lossis cov fluoropolymer tshwj xeeb (xws li Teflon) feem ntau pom zoo. Zam cov khoom uas tuaj yeem degrade lossis outgas.

Kev txiav txim siab tshwj xeeb rau Kev Kho Mob Nitric Oxide

Hauv cov chaw kho mob, qhov uas nqus tau nitric oxide (iNO) yog siv los ua lub ntsws vasodilator, cov txheej txheem purification yog qhov tseem ceeb thiab tswj tau zoo. FDA tso cai txwv nruj rau NO₂ qib hauv cov pa xa tawm (feem ntau <3 ppm).

Kev kho mob iNO cov tshuab siv tshwj xeeb calibrated cov khoom xa tuaj uas txuas ntxiv saib xyuas ob qho tsis muaj thiab tsis muaj₂ concentrations nyob rau hauv lub ua pa Circuit Court. Thaum lub hauv paus roj yog twb siab purity, lub tshuab xa khoom feem ntau koom nrog cov tswv cuab ntawm cov khoom siv tshuaj txhuam los yog siv cov kev ua kom zoo calibrated flow dynamics kom txo tau lub sij hawm sib cuag ntawm NO thiab cov pa oxygen seem hauv lub tshuab ua pa, yog li tiv thaiv kev tsim ntawm NO.₂ ua ntej nws mus txog tus neeg mob.

Kev ceev faj kev nyab xeeb

Kev tuav cov nitric oxide thiab nws cov impurities yuav tsum muaj kev nyab xeeb nruj:

• TOXICITY: Tsis muaj₂ yog tshuaj lom heev thiab corrosive rau txoj kev ua pa. Txawm tias luv luv raug rau siab concentrations yuav ua rau tuag taus.
• Qhov cua: Tag nrho cov txheej txheem purification yuav tsum tau ua nyob rau hauv ib tug zoo-ventilated fume hood.
• Gas saib xyuas: Kev soj ntsuam txuas ntxiv rau ambient NO₂ theem yog qhov tseem ceeb hauv cov cheeb tsam uas TSIS tau ua.
• Kev Tswj Siab: Yuav tsum paub txog lub siab tsim nyob rau hauv lub kaw lus kaw, tshwj xeeb tshaj yog thaum siv cov ntxiab txias uas yuav raug thaiv los ntawm cov dej khov tsis huv.

Tag

To taub yuav ua li cas purify nitric oxide yog qhov tseem ceeb rau nws txoj kev nyab xeeb thiab siv tau zoo hauv kev tshawb fawb, kev lag luam, thiab tshuaj. Los ntawm kev siv txoj hauv kev xws li tshuaj txhuam hniav, kev sib tsoo txias, thiab siv cov khoom siv tshwj xeeb sorbent, cov tshuaj lom thiab cuam tshuam tsis zoo NO₂ tuaj yeem raug tshem tawm zoo. Ua raws li cov txheej txheem kev nyab xeeb nruj, tswj xyuas qhov chaw tsis muaj pa oxygen, thiab ua tib zoo saib xyuas cov txheej txheem purification yog qhov tseem ceeb rau kev ua tiav qhov kev xav tau purity thiab tiv thaiv kom muaj kev phom sij.

Cov lus nug nquag nug (FAQs)