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Melamine i thyaka ra swakudya leri tivekaka leri nga vaka kona eka swiyenge swo karhi swa swakudya hi xihoxo na hi vomu. Xikongomelo xa ndzavisiso lowu akuri ku tiyisisa ku kumiwa naku pima nhlayo ya melamine eka fomula ya ricece na masi ya powder. Nhlayo ya 40 wa swikombiso swa swakudya leswi xavisiwaka, ku katsa na fomula ya tincece na masi ya powder, kusuka eka swifundzha swohambana hambana swa Iran swikamberiwile. Nhlayo ya melamine leyi ringanyetiweke eka tisampulu yikumiwile hiku tirhisa high-performance liquid chromatography-ultraviolet (HPLC-UV) system. Curve ya calibration (R2 = 0.9925) yi akiwile eka ku kumiwa ka melamine eka nhlayo ya 0.1–1.2 μg mL−1. Swipimelo swa ku pima nhlayo na ku kumiwa a ku ri 1 μg mL−1 na 3 μg mL−1, hi ku landzelelana. Melamine yi kamberiwile eka fomula ya ricece na masi ya phoyizeni naswona mbuyelo wu kombisile leswaku ti levele ta melamine eka tisampulu ta fomula ya ricece na masi ya phoyizeni a ti ri 0.001–0.095 mg kg−1 na 0.001–0.004 mg kg−1, hi ku landzelelana. Mimpimanyeto leyi yi fambisana ni milawu ya EU ni Codex Alimentarius. I swa nkoka ku xiya leswaku ku dyiwa ka switirhisiwa leswi swa masi leswingana nhlayo ya melamine leyi hungutiweke aswi veki khombo lerikulu eka rihanyo ra vatirhisi. Leswi swi tlhela swi seketeriwa hi mbuyelo wa nkambisiso wa khombo.
Melamine i organic compound leyingana molecular formula ya C3H6N6, leyi humaka eka cyanamide. Yina ku n’oka ka le hansi swinene ematini naswona yiva kwalomu ka 66% wa nitrogen. Melamine i nkatsakanyo wa tiindasitiri lowu tirhisiwaka ngopfu lowu nga na matirhiselo yo hambana ya le nawini eka vuhumelerisi bya tipulasitiki, manyoro, na switirhisiwa swo lulamisa swakudya (ku katsa na ku paka swakudya na switirhisiwa swa le khixini)1,2. Melamine yitlhela yitirhisiwa tani hi murhi wo rhwala murhi eka vutshunguri bya mavabyi. Xiphemu xa le henhla xa nayitrojini eka melamine xi nga endla leswaku ku tirhisiwa hi ndlela yo biha ka nkatsakanyo na ku nyika swihlawulekisi swa timolekhuli ta tiphrotheyini eka swiaki swa swakudya3,4. Hikokwalaho, ku chela melamine eka switirhisiwa swa swakudya, kukatsa na switirhisiwa swa masi, swi engetela nhlayo ya nitrogen. Xisweswo, hi xihoxo ku gimetiwile leswaku nhlayo ya tiphrotheyini ta masi a yi ri ehenhla ku tlula leswi a yi ri xiswona hakunene.
Eka gram yin’wana na yin’wana ya melamine leyi engeteriweke, nhlayo ya ti protein eka swakudya yita tlakuka hi 0.4%. Hambiswiritano, melamine yi n’oka swinene ematini naswona yi nga vanga khombo lerikulu swinene. Ku chela 1.3 grams ya melamine eka switirhisiwa swa mati swofana na masi swinga engetela nhlayo ya ti protein ta masi hi 30%5,6. Hambi leswi melamine yi cheriwa eka swakudya swa swiharhi hambi ku ri swa vanhu ku engetela nhlayo ya tiphrotheyini7, Khomixini ya Codex Alimentarius (CAC) na valawuri va tiko a va pfumelelanga melamine tanihi xiengeteri xa swakudya naswona va yi xaxamete tanihi leyi nga na khombo loko yi mitiwa, yi hefemuriwa kumbe yi nghenisiwa hi nhlonge. Hi 2012, Ejensi ya Matiko ya Misava ya Vulavisisi bya Khensa ya Nhlangano wa Rihanyo wa Misava (WHO) yi xaxamete melamine tanihi xiaki xa khensa xa Tlilasi 2B hikuva yi nga va na khombo eka rihanyo ra vanhu8. Ku hlangana nkarhi wo leha na melamine swi nga vanga khensa kumbe ku onhaka ka tinso2. Melamine eka swakudya yinga hlangana na cyanuric acid kuva yi endla ti crystals to tshwuka letinga khulukiki ematini letinga vangaka ku onhaka eka tissue ya tinso na xivindzi, xikan’we na cancer ya urinary tract xikan’we naku hunguta miri9,10. Swi nga vanga chefu ya swakudya swa xihatla naswona, eka nhlayo ya le henhla, rifu, ngopfungopfu eka tincece na vana lavatsongo.11 Nhlangano wa Rihanyo wa Misava (WHO) wu tlhele wu veka mpimo lowu amukelekaka wa ku dyiwa ka melamine siku na siku (TDI) eka vanhu eka 0.2 mg/kg ya ntiko wa miri hi siku hi ku ya hi swiletelo swa CAC.12 Ndzawulo ya Swakudya na Mirhi ya le United States (US FDA) yi vekile mpimo wa masalela ya le henhla ya melamine eka 1 mg/kg eka fomula ya tincece na 2.5 mg/kg eka swakudya swin’wana.2,7 Hi Ndzati 2008, ku vikiwile leswaku vaendli vo hlayanyana va fomula ya tincece va le kaya va engeterile melamine eka phoyizeni ya masi ku engetela nhlayo ya tiphrotheyini eka swikumiwa swa vona, leswi endleke leswaku ku va na chefu ya masi ya phoyizeni naswona swi pfuxe mhangu ya chefu ya melamine etikweni hinkwaro leyi vabyaka vana vo tlula 294,000 naswona vo tala va etlela exibedlhele ku tlula 50 000. 13
Ku mamisa aswi koteki minkarhi hinkwayo hikokwalaho ka swilo swohambana hambana swofana na ku nonoka ka vutomi bya le madorobeni, mavabyi ya manana kumbe n’wana, leswi endlaka leswaku kutirhisiwa fomula ya ricece ku phamela tincece. Hikwalaho ka sweswo, tifektri ti simekiwile ku humelerisa fomula ya tincece leyi nga ekusuhi hi laha swi kotekaka ha kona na masi ya mavele hi xivumbeko14. Infant formula leyi xavisiwaka emakete yitala ku endliwa kusuka eka masi ya homu naswona yitala ku endliwa hi nkatsakanyo wo hlawuleka wa mafurha, ti protein, ti carbohydrates, ti vitamins, ti minerali na swin’wana leswi hlanganisiweke. Leswaku yava ekusuhi na masi ya mavele, ti protein na mafurha ya formula ya hambana, naswona kuya hi muxaka wa masi, ya tiyisisiwa hi ti compounds tofana na ti vitamins nati minerali tofana na iron15. Tanihi leswi tincece ti nga ntlawa lowu nga ni vuxiyaxiya naswona ku nga ni khombo ro cheriwa chefu, vuhlayiseki bya ku dya masi ya phoyizeni i ya nkoka swinene eka rihanyo. Endzhaku ka mhaka ya chefu ya melamine eka tincece ta le Chayina, matiko emisaveni hinkwayo ma nyikele nyingiso lowukulu eka mhaka leyi, naswona ku twisisa ka ndhawu leyi na kona ku andzile. Hikokwalaho, swina nkoka swinene ku tiyisisa vulawuri bya vuhumelerisi bya fomula ya tincece leswaku kuta sirheleriwa rihanyo ra tincece. Ku na tindlela to hambana to kuma melamine eka swakudya, ku katsa na high-performance liquid chromatography (HPLC), electrophoresis, ndlela ya switwi, spectrophotometry na antigen-antibody enzyme-linked immunosorbent assay16. Hi 2007, US Food and Drug Administration (FDA) yi tumbuluxile no kandziyisa ndlela ya HPLC yo kumisisa melamine na cyanuric acid eka swakudya, leyi nga ndlela leyi tirhaka swinene yo kumisisa nhlayo ya melamine17.
Nhlayo ya melamine eka fomula ya ricece leyi pimiweke hiku tirhisa thekiniki leyintshwa ya infrared spectroscopy ayi sukela eka 0.33 kuya eka 0.96 milligrams hi kilogram (mg kg-1). 18 Nkambisiso lowu endliweke eSri Lanka wu kume leswaku mpimo wa melamine eka masi ya phoyizeni lowu heleleke wu sukela eka 0.39 ku ya eka 0.84 mg kg-1. Ku engetela kwalano, tisampulu ta fomula ya tincece leti humaka ematikweni mambe tina ti levele tale henhla ta melamine, eka 0.96 na 0.94 mg/kg, hiku landzelelana. Ti levele leti tile hansi ka mpimo wa milawu (1 mg/kg), kambe nongonoko wo veka tihlo wa laveka eka vuhlayiseki bya vatirhisi. 19
Minkambisiso yo hlayanyana yi kambisise mpimo wa melamine eka tifomula ta tincece ta le Iran. Kwalomu ka 65% wa tisampulu atiri na melamine, laha akuri na xiringaniso xa 0.73 mg/kg na xiringaniso xa 3.63 mg/kg. Nkambisiso wun’wana wu vikile leswaku mpimo wa melamine eka fomula ya ricece wu sukela eka 0.35 ku ya eka 3.40 μg/kg, hi xiringaniso xa 1.38 μg/kg. Hiku angarhela, vukona na levele ya melamine eka ti formula ta tincece ta Iran swikamberiwile eka tidyondzo tohambana hambana, laha tisampulu tin’wana letingana melamine ti tlula mpimo lowukulu lowu vekiweke hi valawuri va vulawuri (2.5 mg/kg/feed).
Loko hi tekela enhlokweni ku tirhisiwa lokukulu loku kongomeke na loku nga kongomangiki ka masi ya phoyizeni eka indasitiri ya swakudya na nkoka wo hlawuleka wa fomula ya tincece eka ku phamela vana, ndzavisiso lowu a wu kongomisiwile ku tiyisisa ndlela yo kuma melamine eka masi ya phoyizeni na fomula ya ricece. Entiyisweni, xikongomelo xo sungula xa ndzavisiso lowu a ku ri ku tumbuluxa ndlela ya xihatla, yo olova na ku kongoma ya nhlayo yo kuma ku onhiwa ka melamine eka fomula ya ricece na masi ya phoyizeni hi ku tirhisa high performance liquid chromatography (HPLC) na ultraviolet (UV) detection; Xavumbirhi, xikongomelo xa ndzavisiso lowu akuri ku kumisisa nhlayo ya melamine eka fomula ya ricece na masi ya powder leyi xavisiwaka eka makete wa Iran.
Switirhisiwa leswi tirhisiwaka eka nxopaxopo wa melamine swa hambana kuya hi ndzhawu ya vuhumelerisi bya swakudya. Ndlela ya nxopaxopo wa HPLC-UV leyi nga na vuxiyaxiya na ku tshembheka yi tirhisiwile ku pima masalela ya melamine eka masi na fomula ya ricece. Switirhisiwa swa masi swina ti protein tohambana hambana na mafurha lawa yanga kavanyetaka ku pimiwa ka melamine. Hikwalaho, tanihilaha swi kombisiweke hakona hi Sun et al. 22, maqhinga yo basisa lama faneleke na lama tirhaka ya laveka ku nga si endliwa nxopaxopo wa switirhisiwa. Eka nkambisiso lowu, hi tirhise swisefo swa xiringi leswi lahliwaka. Eka ndzavisiso lowu, hi tirhise kholomo ya C18 ku hambanyisa melamine eka fomula ya ricece na masi ya phoyizeni. Xifaniso xa 1 xi kombisa chromatogram ya ku kumiwa ka melamine. Ku engetela kwalaho, ku vuyiseriwa ka swikombiso leswi nga na 0.1–1.2 mg/kg melamine swi sukela eka 95% ku ya eka 109%, regression equation a yi ri y = 1.2487x − 0.005 (r = 0.9925), naswona mimpimo ya relative standard deviation (RSD) yi sukela eka 0.8 ku ya eka 2%. Data leyi nga kona yi kombisa leswaku ndlela leyi ya tshembheka eka nhlayo ya nhlayo leyi dyondziweke (Table 1). Ndzilakano wa switirhisiwa wa ku kumiwa (LOD) na mpimo wa ku pima mpimo (LOQ) wa melamine a ku ri 1 μg mL−1 na 3 μg mL−1, hi ku landzelelana. Ku engetela kwalano, UV spectrum ya melamine yi kombisile absorption band eka 242 nm. Ndlela yo kuma yi na vuxiyaxiya, ya tshembheka naswona ya lulamile. Ndlela leyi yinga tirhisiwa eka ku kumisisa ka ntolovelo ka levele ya melamine.
Vuyelo lebyi fanaka byi kandziyisiwe hi vatsari vo hlayanyana. Ndlela ya high-performance liquid chromatography-photodiode array (HPLC) yi endliwile eka nxopaxopo wa melamine eka switirhisiwa swa masi. Swipimelo swale hansi swa nhlayo akuri 340 μg kg−1 eka masi ya powder na 280 μg kg−1 eka fomula ya ricece eka 240 nm. Filazzi na van’wana. (2012) va vikile leswaku melamine a yi voniwanga eka fomula ya ricece hi HPLC. Hambiswiritano, 8% wa tisampulu ta masi ya powder ati ri na melamine eka levele ya 0.505–0.86 mg/kg. Tittlemiet et al.23 va endlile ndzavisiso lowu fanaka naswona va kumile nhlayo ya melamine eka fomula ya ricece (nomboro ya xikombiso: 72) hi high-performance liquid chromatography-mass spectrometry/MS (HPLC-MS/MS) kuva kwalomu ka 0.0431–0.346 mg kg−1. Eka nkambisiso lowu endliweke hi Venkatasamy et al. (2010), endlelo ra tikhemikhali ta rihlaza (handle ka acetonitrile) na reversed-phase high-performance liquid chromatography (RP-HPLC) switirhisiwile ku ringanyeta melamine eka fomula ya ricece na masi. Nhlayo ya nhlayo ya xikombiso ayi suka eka 1.0 kuya eka 80 g/mL naswona nhlamulo ayi ri linear (r > 0.999). Ndlela leyi yi kombisile ku vuyelela ka 97.2–101.2 eka nhlayo ya nhlayo ya 5–40 g/mL naswona ku humelerisiwa akuri ehansi ka 1.0% relative standard deviation. Ku tlula kwalaho, LOD na LOQ leswi xiyiweke a swi ri 0.1 g mL−1 na 0.2 g mL−124, hi ku landzelelana. Lutter na van’wana. (2011) va kumile ku thyakisa ka melamine eka masi ya homu na fomula ya ricece leyi simekiweke eka masi hiku tirhisa HPLC-UV. Nhlayo ya melamine ayi sukela eka < 0.2 kuya eka 2.52 mg kg−1. Linear dynamic range ya ndlela ya HPLC-UV akuri 0.05 kuya eka 2.5 mg kg−1 eka masi ya homu, 0.13 kuya eka 6.25 mg kg−1 eka fomula ya ricece leyingana xiphemu xa protein mass xa <15%, na 0.25 kuya eka 12.5 mg kg−1 eka fomula ya ricece leyingana protein mass fraction ya 15%. Mbuyelo wa LOD (na LOQ) akuri 0.03 mg kg−1 (0.09 mg kg−1) eka masi ya homu, 0.06 mg kg−1 (0.18 mg kg−1) eka fomula ya ricece <15% protein, na 0.12 mg kg−1 (0.36 mg kg−1) eka fomula ya ricece ya 15% protein, na signal-to-noise ratio ya 3 na 1025 eka LOD na LOQ, hi ku landzelelana. Diebes na van’wana. (2012) va lavisisile ti levele ta melamine eka tisampulu ta fomula ya ricece na milk powder hiku tirhisa HPLC/DMD. Eka fomula ya ricece, swiyimo swale hansi na swale henhla akuri 9.49 mg kg−1 na 258 mg kg−1, hiku landzelelana. Mpimo wa ku kumiwa (LOD) a wu ri 0.05 mg kg−1.
Javaid na van’wana. va vikile leswaku masalela ya melamine eka fomula ya ricece a ya ri eka mpimo wa 0.002–2 mg kg−1 hi Fourier transform infrared spectroscopy (FT-MIR) (LOD = 1 mg kg−1; LOQ = 3.5 mg kg−1). Rezai et al.27 va ringanyete ndlela ya HPLC-DDA (λ = 220 nm) ku ringanyeta melamine naswona va fikelerile LOQ ya 0.08 μg mL−1 eka masi ya powder, leyi ayi ri ehansi ka levele leyi kumiweke eka ndzavisiso lowu. Sun na van’wana. yi tumbuluxile RP-HPLC-DAD ya ku kumiwa ka melamine eka masi ya mati hi solid phase extraction (SPE). Va kumile LOD na LOQ ya 18 na 60 μg kg−128, hiku landzelelana, leswinga na vuxiyaxiya kutlula dyondzo ya sweswi. Montesano na van’wana. yi tiyisisile ku tirha kahle ka ndlela ya HPLC-DMD eka ku kamberiwa ka nhlayo ya melamine eka swiengetelo swa tiphrotheyini hi mpimo wa ku pima nhlayo ya 0.05–3 mg/kg, leyi a yi nga ri na vuxiyaxiya ku tlula ndlela leyi tirhisiweke eka ndzavisiso lowu29.
Handle ko kanakana, tilaboratori ta vuxopaxopi ti tlanga xiave xa nkoka eku sirheleleni ka mbango hi ku veka tihlo eka swilo leswi thyakeke eka swikombiso swo hambana. Hambiswiritano, kutirhisiwa ka nhlayo leyikulu ya ti reagents nati solvents hinkarhi wa nxopaxopo swinga endla leswaku kuva na masalela lawa yanga na khombo. Hikwalaho, green analytical chemistry (GAC) yi tumbuluxiwile hi 2000 ku hunguta kumbe ku herisa switandzhaku swo biha swa maendlelo ya nxopaxopo eka vafambisi na mbango26. Maendlelo ya ndhavuko yo kuma melamine ku katsa na chromatography, electrophoresis, capillary electrophoresis, na enzyme-linked immunosorbent assay (ELISA) ya tirhisiwile ku kuma melamine. Hambiswiritano, exikarhi ka tindlela to tala to kuma, switwi swa tikhemikhali ta gezi swi koke nyingiso lowukulu hikwalaho ka ku twisisa ka swona lokunene, ku hlawula, nkarhi wa nxopaxopo wa xihatla, na swihlawulekisi leswi tirhisiwaka hi ku olova30,31. Green nanotechnology yi tirhisa tindlela ta biological ku hlanganisa ti nanomaterials, leswi nga hungutaka ku tumbuluxiwa ka thyaka leri nga na khombo na ku tirhisiwa ka eneji, hi ndlela yoleyo ku tlakusa ku tirhisiwa ka maendlelo lama nga ta tshama nkarhi wo leha. Ti nanocomposites, xikombiso, leti endliweke kusuka eka switirhisiwa leswinga onhiki mbango, tinga tirhisiwa eka ti biosensors ku kuma swilo swofana na melamine32,33,34.
Dyondzo yikombisa leswaku solid-phase microextraction (SPME) yitirhisiwa kahle hikokwalaho ka ku tirhisiwa ka eneji yale henhla xikan’we naku tshamiseka loko ku pimanyisiwa na tindlela ta ndhavuko to humesa. Ku va na xinghana na mbango na ku tirhisa eneji hi ndlela leyinene ka SPME swi endla leswaku yi va ndlela yin’wana ya kahle swinene eka tindlela ta ndhavuko to humesa eka tikhemikhali ta nxopaxopo na ku nyika ndlela leyi nga ta tshama nkarhi wo leha no tirha kahle eka ku lulamisela xikombiso35.
Hi lembe ra 2013, Wu na van’wana. yi tumbuluxile biosensor ya surface plasmon resonance (mini-SPR) leyi nga na vuxiyaxiya swinene na ku hlawula leyi tirhisaka ku hlanganisiwa exikarhi ka tiantibodies ta melamine na anti-melamine ku hatlisa ku kuma melamine eka fomula ya ricece hi ku tirhisa immunoassay. SPR biosensor leyi hlanganisiweke na immunoassay (ku tirhisa melamine-conjugated bovine serum albumin) i thekinoloji yo olova ku yi tirhisa naswona ya ntsengo wa le hansi leyi nga na mpimo wo kuma wa 0.02 μg mL-136 ntsena.
Nasiri na Abbasian va tirhisile xitwi lexi rhwalekaka xa vuswikoti bya le henhla lexi hlanganisiweke na swihlanganisi swa graphene oxide-chitosan (GOCS) ku kuma melamine eka swikombiso swa mabindzu37. Endlelo leri ri kombisile ku hlawula lokukulu swinene, ku pakanisa na ku hlamula. Sensor ya GOCS yi kombisile ku twisisa loku hlamarisaka (239.1 μM−1), linear range ya 0.01 kuya eka 200 μM, affinity constant ya 1.73 × 104, na LOD yo fika eka 10 nM. Ku tlula kwalaho, nkambisiso lowu endliweke hi Chandrasekhar et al. hi 2024 yi amukerile endlelo leri nga onhiki ntumbuluko na ku hunguta mali. Va tirhise papaya peel extract tani hi reducing agent kuva va endla ti zinc oxide nanoparticles (ZnO-NPs) hi ndlela ya eco-friendly. Endzhaku ka sweswo, endlelo ro hlawuleka ra micro-Raman spectroscopy ri endliwile ku kumisisa melamine eka fomula ya ricece. Ti ZnO-NPs leti humaka eka thyaka ra vurimi ti kombisile vuswikoti tani hi xitirhisiwa xa nkoka xo kambela na thekinoloji yo tshembheka, ya ntsengo wa le hansi yo veka tihlo na ku kuma melamine38.
Alizadeh na van’wana. (2024) va tirhise pulatifomo ya fluorescence ya metal-organic framework (MOF) leyi nga na vuxiyaxiya swinene ku kumisisa melamine eka masi ya phoyizeni. Linear range na limitation yale hansi ya sensor, leyi kumiweke hiku tirhisa 3σ/S, akuri 40 kuya eka 396.45 nM (leswi ringanaka na 25 μg kg−1 kuya eka 0.25 mg kg−1) na 40 nM (leswi ringanaka na 25 μg kg−1), hiku landzelelana. Nhlayo leyi yile hansi swinene ka ti levele ta masalela yale henhla (MRLs) leti vekiweke eka ku tiviwa ka melamine eka fomula ya ricece (1 mg kg−1) na swikombiso swin’wana swa swakudya/swidyelo (2.5 mg kg−1). Fluorescent sensor (terbium (Tb)@NH2-MIL-253(Al)MOF) yi kombisile ku pakanisa ka le henhla na vuswikoti byo pima lebyi kongomeke kutlula HPLC39 eka ku kuma melamine eka masi ya powder. Ti biosensors nati nanocomposites eka tikhemikhali ta rihlaza aswi ndlandlamuxi ntsena vuswikoti byo kuma kambe switlhela swi hunguta makhombo ya mbango hiku fambisana na milawu ya nhluvukiso lowu nga heriki.
Misinya ya milawu ya tikhemikhali ta rihlaza yi tirhisiwile eka tindlela to hambana hambana to kumisisa melamine. Ndlela yin’wana i ku tumbuluxiwa ka ndlela ya green dispersive solid-phase microextraction hiku tirhisa natural polar polymer β-cyclodextrin leyi hlanganisiweke na citric acid kuva ku humesiwa kahle melamine 40 kusuka eka tisampulu tofana na fomula ya ricece na mati yo hisa. Ndlela yin’wana yitirhisa Mannich reaction eka ku kumisisa melamine eka tisampulu ta masi. Ndlela leyi ayi durhi, ayi onhi mbango, naswona yi lulamile swinene na linear range ya 0.1–2.5 ppm xikan’we na limitation yale hansi ya 41. Kuya emahlweni, ndlela yoka yinga durhi naswona yinga onhi mbango eka ku kumisisa nhlayo ya melamine eka masi ya mati na fomula ya ricece yi endliwile hiku tirhisa Fourier transform infrared transmission spectroscopy hi ku pakanisa lokukulu na swipimelo swa ku kumiwa swa 1 ppm na 3.5 ppm, hi ku landzelelana 42. Maendlelo lawa ya kombisa ku tirhisiwa ka milawu ya tikhemikhali ta rihlaza eka ku tumbuluxiwa ka tindlela leti tirhaka kahle na leti nga ta tshama nkarhi wo leha to kumisisa melamine.
Mindzavisiso yo hlaya yi ringanyete tindlela ta vutumbuluxi to kuma melamine, ku fana na ku tirhisiwa ka ku humesiwa ka xiphemu xo tiya na chromatography ya mati ya matirhelo ya le henhla (HPLC)43, xikan’we na chromatography ya mati ya matirhelo ya le henhla yo hatlisa (HPLC), leyi nga laviki ti-pre-treatment to rharhangana kumbe ti-ion-pair reagents, hi ndlela yoleyo ku hunguta nhlayo ya thyaka ra tikhemikhali44. Maendlelo lawa aya nyiki ntsena mbuyelo lowu kongomeke eka ku kumiwa ka melamine eka switirhisiwa swa masi, kambe yatlhela ya landzelela milawu ya tikhemikhali ta rihlaza, ku hunguta kutirhisiwa ka ti khemikhali letinga na khombo xikan’we naku hunguta ku khumbeka hinkwako ka mbango eka maendlelo ya vuxopaxopi.
Tisampulu ta makume mune ta mavito yo hambana ti kamberiwile hi ku phindha-phindha kanharhu, naswona mbuyelo wu nyikiwile eka Tafula ra 2. Ti levele ta melamine eka tisampulu ta fomula ya ricece na milk powder ti sukela eka 0.001 ku ya eka 0.004 mg/kg na ku suka eka 0.001 ku ya eka 0.095 mg/kg, hi ku landzelelana. Ku hava ku cinca lokukulu loku voniweke exikarhi ka mintlawa yinharhu ya malembe ya fomula ya ricece. Ku engetela kwalano, melamine yikumeke eka 80% wa masi ya powder, kambe 65% wa ti formula ta tincece ati thyakisiwile hi melamine.
Nhlayo ya melamine eka industrial milk powder ayi tlakukile kutlula eka formula ya ricece, naswona ku hambana akuri ka nkoka (p<0.05) (Figure 2).
Mbuyelo lowu kumiweke a wu ri ehansi ka swipimelo leswi vekiweke hi FDA (ehansi ka 1 na 2.5 mg/kg). Ku engetela kwalano, mbuyelo wu fambisana na swipimelo leswi vekiweke hi CAC (2010) na EU45,46, i.e. mpimo lowukulu lowu pfumeleriweke i 1 mg kg-1 eka fomula ya ricece na 2.5 mg kg-1 eka switirhisiwa swa masi.
Kuya hi ndzavisiso wa 2023 hi Ghanati et al.47, nhlayo ya melamine eka tinxaka tohambana hambana ta masi lawa ya pakiweke e Iran ayi sukela eka 50.7 kuya eka 790 μg kg−1. Vuyelo bya vona a byi ri ehansi ka mpimo lowu pfumeleriweke wa FDA. Mimbuyelo ya hina yi le hansi ku tlula ya Shoder et al.48 na Rima et al.49. Shoder na van’wana. (2010) va kumile leswaku ti levele ta melamine eka milk powder (n=49) leti kumiweke hi ELISA ti sukela eka 0.5 kuya eka 5.5 mg/kg. Rima na van’wana. va kambisisile masalela ya melamine eka masi ya powder hi fluorescence spectrophotometry naswona va kumile leswaku nhlayo ya melamine eka masi ya powder ayiri 0.72–5.76 mg/kg. Dyondzo yi endliwile e Canada hi 2011 ku langutisisa ti levele ta melamine eka fomula ya ricece (n=94) hiku tirhisa liquid chromatography (LC/MS). Ti concentrations ta melamine tikumeke tiri ehansi ka mpimo lowu amukelekaka (preliminary standard: 0.5 mg kg−1). A swi tikombi leswaku ti levele ta melamine ta vuxisi leti kumiweke a ku ri rhengu leri tirhisiweke ku engetela nhlayo ya tiphrotheyini. Hambiswiritano, a swi nge hlamuseriwa hi ku tirhisiwa ka manyoro, ku rhurhisiwa ka leswi nga endzeni ka xigwitsirisi kumbe swilo leswi fanaka. Ku tlula kwalaho, xihlovo xa melamine eka masi ya phoyizeni lama nghenisiwaka eCanada a xi paluxiwanga50.
Hassani na van’wana. yi pimile nhlayo ya melamine eka masi ya powder na masi ya mati eka makete wa Iran hi 2013 naswona yi kumile mbuyelo lowu fanaka. Mbuyelo wu kombisile leswaku handle ka brand yin’we ya masi ya powder na masi ya mati, tisampulu tin’wana hinkwato ati thyakisiwile hi melamine, laha ti levele ati sukela eka 1.50 kuya eka 30.32 μg g−1 eka masi ya powder na 0.11 kuya eka 1.48 μg ml−1 eka masi. Lexi xiyekaka, cyanuric acid ayi voniwanga eka yin’wana ya tisampulu, leswinga hunguta ku koteka ka chefu ya melamine eka vaxavi. 51 Mindzavisiso ya khale yi kamberile nhlayo ya melamine eka switirhisiwa swa chokoleti leswi nga na masi ya phoyizeni. Kwalomu ka 94% wa tisampulu leti humaka ematikweni mambe na 77% wa tisampulu ta le Iran a ti ri na melamine. Ti levele ta melamine eka tisampulu leti humaka ematikweni mambe ati sukela eka 0.032 kuya eka 2.692 mg/kg, kasi letinga eka tisampulu ta Iran ati sukela eka 0.013 kuya eka 2.600 mg/kg. Hi ku angarhela, melamine yi kumiwile eka 85% wa tisampulu, kambe i brand yin’we ntsena yo karhi leyi a yi ri na ti levele leti nga ehenhla ka mpimo lowu pfumeleriwaka.44 Tittlemier et al. va vikile ti levele ta melamine eka masi ya powder kusuka eka 0.00528 kuya eka 0.0122 mg/kg.
Tafula ra 3 ri katsakanya mimbuyelo ya nkambisiso wa khombo eka mintlawa yinharhu ya malembe. Khombo a ri ri ehansi ka 1 eka mintlawa hinkwayo ya malembe. Xisweswo, a ku na khombo ra rihanyo leri nga riki ra khensa ku suka eka melamine eka fomula ya ricece.
Ti levele tale hansi ta thyaka eka switirhisiwa swa masi tingava hikokwalaho ka ku thyakisa lokunga endliwangiki hi vomu hinkarhi waku lulamisiwa, kasi ti levele tale henhla tingava hikokwalaho ka ku engeteriwa hi vomu. Kuya emahlweni, khombo hinkwaro eka rihanyo ra vanhu kusuka eka ku dya switirhisiwa swa masi leswingana ti levele tale hansi ta melamine ri tekiwa riri ehansi. Ku nga gimetiwa leswaku ku dya switirhisiwa leswi nga na swiyimo swa le hansi swonghasi swa melamine a swi veki khombo eka rihanyo ra vatirhisi52.
Loko hi tekela enhlokweni nkoka wa vulawuri bya vuhlayiseki bya swakudya eka indasitiri ya masi, ngopfu ngopfu eka ku sirhelela rihanyo ra vaaki, i swa nkoka swinene ku tumbuluxa na ku tiyisisa ndlela yo kambela na ku pimanisa ti levele ta melamine na masalela eka milk powder na fomula ya ricece. Ndlela yo olova no kongoma ya HPLC-UV spectrophotometric yi endliwile ku kumisisa melamine eka fomula ya ricece na masi ya powder. Ndlela leyi yi tiyisisiwile ku tiyisisa ku tshembeka na ku pakanisa ka yona. Swipimelo swaku kumiwa naku pima nhlayo ya ndlela leyi swikombisiwile kuva swiri na vuxiyaxiya kuringanela ku pima ti levele ta melamine eka fomula ya ricece na masi ya powder. Hikuya hi data ya hina, melamine yikumeke eka vunyingi bya tisampulu ta Iran. Ti levele hinkwato ta melamine leti kumiweke a ti ri ehansi ka swipimelo leswi pfumeleriwaka leswi vekiweke hi CAC, leswi kombisaka leswaku ku dyiwa ka tinxaka leti ta switirhisiwa swa masi a swi veki khombo eka rihanyo ra vanhu.
Switirhisiwa hinkwaswo swa tikhemikhali leswi tirhisiweke a swi ri swa giredi ya nxopaxopo: melamine (2,4,6-triamino-1,3,5-triazine) 99% yo basa (Sigma-Aldrich, St. Louis, MO); Acetonitrile ya giredi ya HPLC (Merck, Darmstadt, Jarimani); mati lama tengeke swinene (Millipore, Morfheim, Furwa). Tifiltara ta xiringi leti lahliwaka (Chromafil Xtra PVDF-45/25, sayizi ya pore 0.45 μm, dyayimeta ya membrane 25 mm) (Macherey-Nagel, Düren, Germany).
Ku lunghiselela swikombiso leswi swi tirhisiwile ku hlamba hi ultrasonic (Elma, Germany), centrifuge (Beckman Coulter, Krefeld, Germany) na HPLC (KNAUER, Germany).
Ku tirhisiwile chromatograph ya mati ya matirhelo ya le henhla (KNAUER, Germany) leyi hlomisiweke hi xitivi xa UV. Swiyimo swa nxopaxopo wa HPLC a swi ri hi ndlela leyi landzelaka: sisiteme ya UHPLC Ultimate leyi hlomisiweke hi kholomo ya nxopaxopo ya ODS-3 C18 (4.6 mm × 250 mm, sayizi ya swiphemuphemu 5 μm) (MZ, Germany) yi tirhisiwile. HPLC eluent (mobile phase) akuri nkatsakanyo wa TFA/methanol (450:50 mL) na nhlayo ya ku khuluka ya 1 mL min-1. Ku leha ka magandlati ya ku kumiwa a ku ri 242 nm. Volume ya injection akuri 100 μL, mahiselo ya kholomo akuri 20 °C. Leswi nkarhi wo khoma murhi wu leheke (15 wa timinete), ku cheriwa loku landzelaka ku fanele ku endliwa endzhaku ka 25 wa timinete. Melamine yi tiviwile hiku pimanisa nkarhi wo khoma na nhlohlorhi ya UV spectrum ya swipimelo swa melamine.
Nkatsakanyo wa ntolovelo wa melamine (10 μg/mL) wu lulamisiwile hiku tirhisa mati naswona wu hlayisiwile eka firiji (4 °C) ekule na ku vonakala. Dilute stock solution na mobile phase naku lulamisa ti working standard solutions. Nkatsakanyo wun’wana na wun’wana wa ntolovelo wu cheriwile eka HPLC minkarhi ya 7. Xiringaniso xa calibration 10 xi hlayiwile hi nxopaxopo wa regression wa ndzhawu ya nhlohlorhi leyi vekiweke na nhlayo leyi kumiweke.
Powder ya masi ya homu leyi xavisiwaka (20 wa tisampulu) na swikombiso swa mavito yohambana hambana ya fomula ya ricece leyi simekiweke eka masi ya homu (20 wa tisampulu) swixaviwile kusuka eka switolo leswikulu swa laha kaya na tikhemisi e Iran ku phamela tincece ta mintlawa yohambana hambana ya malembe (0–6 wa tinhweti, 6–12 wa tinhweti, na >12 wa tinhweti) naswona ti hlayisiwile eka mahiselo ya efrijini (4 °C) kufikela eka ku kamberiwa. Kutani, 1 ± 0.01 g ya homogenized milk powder yi pimiwe kutani yi hlanganisiwa na acetonitrile:mati (50:50, v/v; 5 mL). Nkatsakanyo wu hlanganisiwile kuringana 1 min, kutani wu sonicated eka ultrasonic bath kuringana 30 min, naswona ekuheteleleni wu rhurhumerisiwile kuringana 1 min. Kutani nkatsakanyo wu centrifuged eka 9000 × g kuringana 10 min eka mahiselo ya kamara naswona supernatant yi sefiwile eka 2 ml autosampler vial hiku tirhisa 0.45 μm syringe filter. Kutani filtrate (250 μl) yi hlanganisiwile na mati (750 μl) kutani yi cheriwa eka HPLC system10,42.
Ku tiyisisa ndlela, hi kumile ku vuyiseriwa, ku pakanisa, mpimo wa ku kumiwa (LOD), mpimo wa ku pima nhlayo (LOQ), na ku kongoma ehansi ka swiyimo leswinene. LOD yi hlamuseriwile tanihi nhlayo ya xikombiso leyi nga na ku tlakuka ka nhlohlorhi loku phindhiweke kanharhu eka mpimo wa mpfumawulo wa masungulo. Hi tlhelo rin’wana, nhlayo ya xikombiso leyi nga na ku tlakuka ka nhlohlorhi loku phindhiweke ka khume ku tlula mpimo wa xigingi eka mpfumawulo wu hlamuseriwile tanihi LOQ.
Nhlamulo ya xitirhisiwa yi kumiwile hi ku tirhisa curve ya calibration leyi vumbiwaka hi tinhla ta nkombo ta data. Ku tirhisiwile nhlayo yohambana hambana ya melamine (0, 0.2, 0.3, 0.5, 0.8, 1 na 1.2). Ku kumiwile linearity ya endlelo ro hlayela melamine. Ku engetela kwalaho, ku engeteriwile swiyimo swo hlayanyana swo hambana-hambana swa melamine eka swikombiso leswi nga riki na nchumu. Calibration curve yi akiwile hiku ya emahlweni yi chela 0.1–1.2 μg mL−1 ya standard melamine solution eka formula ya ricece na tisampulu ta masi ya powder naswona R2 ya yona = 0.9925. Ku lulama ku kamberiwile hi ku phindha-phindha na ku tlheriseriwa ka endlelo naswona ku fikeleriwile hi ku chela swikombiso eka masiku yo sungula na manharhu lama landzeleke (hi ku phindha-phindha kanharhu). Ku phindha-phindha ka ndlela leyi ku kamberiwile hi ku hlayela RSD % eka ti concentrations tinharhu to hambana ta melamine leyi engeteriweke. Tidyondzo ta ku vuyisa ti endliwile ku kumisisa ku kongoma. Mpimo wa ku vuyelela hi ndlela yo humesa wu hlayiwile eka swiyimo swinharhu swa nhlayo ya melamine (0.1, 1.2, 2) eka swikombiso swa fomula ya ricece na masi yo oma9,11,15.
Ku dyiwa ka siku na siku loku ringanyetiweke (EDI) ku kumiwile hi ku tirhisa fomula leyi landzelaka: EDI = Ci × Cc/BW.
Laha Ci kunga nhlayo ya xikarhi ya melamine, Cc i masi lawa ya dyiwaka naswona BW kunga ntiko wa xikarhi wa vana.
Nxopaxopo wa datha wu endliwile hi ku tirhisa SPSS 24. Ntolovelo wu kamberiwile hi ku tirhisa xikambelo xa Kolmogorov-Smirnov; datha hinkwayo a yi ri swikambelo swa nonparametric (p = 0). Hikokwalaho, xikambelo xa Kruskal-Wallis na xikambelo xa Mann-Whitney switirhisiwile ku kumisisa ku hambana lokukulu exikarhi ka mintlawa.
Ingelfinger, Jr. Melamine na nkucetelo wa yona eka ku thyakisa swakudya swa misava hinkwayo. Nyuziphepha ya Vutshunguri ya New England 359(26), 2745–2748 (2008).
Lynch, R. A., na van’wana. Vuyelo bya pH eka ku rhurha ka melamine eka swibya swa vana. Nkandziyiso wa Matiko ya Misava wa ku Thyakisa Swakudya, 2, 1–8 (2015).
Barrett, MP na Gilbert, IH Ku ​​kongomisa swihlanganisi leswi nga na chefu endzeni ka ti trypanosomes. Nhluvuko eka Parasitology 63, 125–183 (2006).
Nirman, M. F., na van’wana. Ku kamberiwa ka in vitro na in vivo ka melamine dendrimers tani hi mimovha yo yisa mirhi. Nkandziyiso wa Matiko ya Misava wa Vukhemisi, 281(1–2), 129–132(2004).
Nhlangano wa Rihanyo wa Misava Hinkwayo. Minhlangano ya Vativi 1–4 ku kambisisa swiyenge swa toxicological swa melamine na cyanuric acid (2008).
Howe, A. K.-C., Kwan, T. H. na Lee, P. K.-T. Chefu ya melamine na tinso. Nyuziphepha ya Nhlangano wa Amerika wa Nephrology 20(2), 245–250 (2009).
Ozturk, S. na Demir, N. Ku tumbuluxiwa ka novhele ya IMAC adsorbent yo kuma melamine eka switirhisiwa swa masi hi high performance liquid chromatography (HPLC). Nyuziphepha ya ku Hlanganisiwa ka Swakudya na Nxopaxopo 100, 103931 (2021).
Chansuvarn, V., Panic, S. na Imim, A. Ku kumiwa ko olova ka spectrophotometric ka melamine eka masi ya mati leswi simekiweke eka Mannich green reaction. Xiphepherhele xa khemikhali. Acta Xiphemu xa A Mol. Biomol. Xiphepherhele xa spectrosc. 113, 154–158 (2013) Xihlamusela-marito xa Xitsonga.
Deabes, M. na El-Habib, R. Ku kumiwa ka melamine eka fomula ya ricece, masi ya phoyizeni na swikombiso swa pangasius hi HPLC/diode array chromatography. Nyuziphepha ya Nxopaxopo wa Chefu ya Ntivo-mbango, 2(137), 2161–0525.1000137 (2012).
Skinner, KG, Thomas, JD, na Osterloh, JD Vuxungu bya melamine. Nyuziphepha ya Vutshunguri bya Chefu, 6, 50–55 (2010).
Nhlangano wa Rihanyo wa Misava (WHO), Toxicology na swiyenge swa rihanyo swa melamine na cyanuric acid: Xiviko xa nhlengeletano ya vativi va ntirhisano wa WHO/FAO leyi seketeriweke hi Health Canada, Ottawa, Canada, 1-4 Dzivamisoko 2008 (2009).
Korma, S. A., na van’wana. Dyondzo yo pimanisa ya xivumbeko xa lipid na khwalithi ya powder ya fomula ya ricece leyi nga na ti lipids ta xivumbeko xa ntirho wa novhele na fomula ya ricece ya mabindzu. Vulavisisi bya Swakudya bya le Yuropa na Thekinoloji 246, 2569–2586 (2020).
El-Waseef, M. na Hashem, H. Ku ndlandlamuxiwa ka nkoka wa swakudya, swihlawulekisi swa khwalithi na vutomi bya xelufu ya fomula ya ricece hi ku tirhisa mafurha ya ncindzu. Middle East Journal ya Vulavisisi bya Vurimi 6, 274–281 (2017).
Yin, W., na van’wana. Ku endliwa ka ti antibodies ta monoclonal eka melamine xikan’we naku tumbuluxiwa ka ndlela ya ELISA yo phikizana leyinga kongomangiki eka ku kumiwa ka melamine eka masi yoka yanga swekiwanga, masi yo oma, na swakudya swa swifuwo. Nyuziphepha ya Vurimi na Tikhemikhali ta Swakudya 58(14), 8152–8157 (2010).