Latent teebmeem hauv cov khoom ua si
Chromium yog cov hlau ntau, feem ntau yog Cr (III) thiab Cr (VI).Ntawm lawv, cov tshuaj lom ntawm Cr (VI) yog ntau tshaj 100 npaug ntawm Cr (III), uas muaj cov tshuaj lom neeg loj heev rau tib neeg, tsiaj txhu thiab cov kab mob hauv dej.Nws tau teev tseg raws li chav kawm I carcinogen los ntawm lub koom haum thoob ntiaj teb rau kev tshawb fawb mob qog noj ntshav (IARC).Tab sis ntau tus neeg tsis paub tias muaj kev kub ntxhov ntau dhau Cr (VI) hauv cov menyuam yaus cov khoom ua si!
Cr (VI) yooj yim heev rau nqus los ntawm tib neeg lub cev.Nws tuaj yeem cuam tshuam tib neeg lub cev los ntawm kev zom zaub mov, ua pa, tawv nqaij thiab mucous membrane.Nws tau raug tshaj tawm tias thaum tib neeg ua pa uas muaj qhov sib txawv ntawm Cr (VI), lawv yuav muaj qhov sib txawv ntawm hoarseness, atrophy ntawm qhov ntswg mucosa, thiab txawm perforation ntawm qhov ntswg septum thiab bronchiectasis.Nws tuaj yeem ua rau ntuav thiab mob plab.Dermatitis thiab eczema tuaj yeem tshwm sim los ntawm kev cuam tshuam ntawm daim tawv nqaij.Qhov teeb meem loj tshaj plaws yog kev raug mus ntev los yog luv luv los yog nqus tau cov kab mob carcinogenic.
Nyob rau lub Plaub Hlis 2019, European Committee for Standardization (CEN) tau tshaj tawm cov khoom ua si kev nyab xeeb tus qauv EN71 Tshooj 3: kev tsiv teb tsaws ntawm cov ntsiab lus tshwj xeeb (2019 version).Ntawm lawv, cov ntsiab lus hloov kho rau Cr(VI) nrhiav tau yog:
● Tus nqi txwv ntawm Cr (VI) ntawm peb hom khoom, hloov ntawm 0.2mg / kg rau 0.053mg / kg, siv rau lub Kaum Ib Hlis 18, 2019.
● txoj kev xeem ntawm Cr (VI) tau raug kho dua, thiab cov kev hloov kho tshiab tuaj yeem muaj qhov txwv ntawm txhua pawg ntawm cov ntaub ntawv.Txoj kev sim hloov ntawm LC-ICPMS rau IC-ICPMS.
SHINE kev daws teeb meem
Raws li EN71-3: 2019 tus qauv ntawm European Union, kev sib cais thiab kuaj pom ntawm Cr (III) thiab Cr (VI) hauv cov khoom ua si tuaj yeem paub tau los ntawm kev siv SINE CIC-D120 ion chromatograph thiab NCS plasma MS 300 inductively coupled plasma mass spectrometer.Lub sijhawm kuaj pom yog nyob rau hauv 120 vib nas this, thiab kev sib raug zoo yog qhov zoo.Nyob rau hauv cov xwm txheej ntawm kev txhaj tshuaj Cr (III) thiab Cr (VI), qhov kev kuaj pom tsis pub dhau 5ng / L thiab 6ng / L feem, thiab qhov rhiab heev ua tau raws li cov qauv kev kuaj pom kev txwv.
1. Instrument configuration
2. Cov xwm txheej kuaj pom
Ion chromatograph mob
Mobile theem: 70 mM NH4NO3, 0.6 mM EDTA (2Na), pH 71, Elution hom: Isometric elution
Tus nqi ntws (mL / min): 1.0
Txhaj ntim (µL): 200
Qauv: AG7
ICP-MS mob
RF hwj chim (W): 1380
Cov pa roj (L / min): 0.97
Kev ntsuas huab hwm coj: 52C
Qhov sib txawv voltage (V): 2860
Duration (s): 150
3. Reagents thiab cov qauv kev daws teeb meem
Cr (III) thiab Cr (VI) tus qauv kev daws teeb meem: kev lag luam muaj ntawv pov thawj cov qauv kev daws teeb meem
Concentrated ammonia: superior ntshiab
Concentrated nitric acid: superior purity
EDTA-2Na: superior purity
Ultra ntshiab dej: resistivity ≥ 18.25 m Ω· cm (25 ℃).
Kev npaj ntawm Cr(VI) ua hauj lwm nkhaus: dilute Cr(VI) txheem tov nrog ultra ntshiab dej mus rau qhov yuav tsum tau concentration kauj ruam yog kauj ruam.
Kev npaj ntawm Cr (III) thiab Cr (VI) tov tov ua hauj lwm nkhaus: noj ib tug npaum li cas ntawm Cr (III) thiab Cr (VI) txheem tov, ntxiv 10mL ntawm 40mM EDTA-2Na rau hauv ib tug 50mL volumetric hwj, kho tus nqi pH mus txog 7.1, sov nws nyob rau hauv ib da dej ntawm 70 ℃ rau 15min, kho lub ntim, thiab ua tus txheej txheem tov tov nrog rau qhov yuav tsum tau concentration los ntawm tib txoj kev.
4. Kev kuaj pom qhov tshwm sim
Raws li txoj kev sim pom zoo ntawm EN71-3, Cr (III) tau sib xyaw nrog EDTA-2Na, thiab Cr(III) thiab Cr(VI) tau sib cais zoo.Cov chromatogram ntawm cov qauv tom qab peb qhov kev rov ua dua tau pom tias qhov rov ua tau zoo dua, thiab qhov txheeb ze tus qauv sib txawv (RSD) ntawm thaj chaw ncov tsawg dua 3%.Kev kuaj pom qhov txwv yog 6ng / L.
Txhaj cais chromatogram ntawm Cr (III) - EDTA thiab Cr (VI) tov tov
Chromatogram overlay ntawm peb qhov kev txhaj tshuaj ntawm 0.1ug / L Cr (III)-EDTA thiab Cr(VI) tov tov (Stability ntawm 0.1ppbCr (III) + Cr (VI) qauv)
0.005-1.000 ug/L Cr (III) calibration nkhaus (Peak cheeb tsam linearity) qauv)
0.005-1.000 ug / L Cr (VI) calibration nkhaus (Peak siab linearity) ea linearity qauv)
Lub sij hawm xa tuaj: Plaub Hlis-18-2023