Tin compounds in food – their distribution and determination

Po a ina s o Slo ak Jou nal o Food Sciences Volume 13 369 No. 1/2019 Po a ina s o Slo ak Jou nal o Food Sciences ol. 13, 2019, no. 1, p. 369-377 h ps://doi.o g/10.5219/1041 Recei ed: 8 Feb ua y 2019. Accep ed: 12 Ma ch 2019. A ailable online: 28 May 2019 a www.po a ina s o.com © 2019 Po a ina s o Slo ak Jou nal o Food Sciences, License: CC BY 3.0 ISSN 1337-0960 (online) TIN COMPOUNDS IN FOOD – THEIR DISTRIBUTION AND DETERMINATION Mi osla Fiše a, S anisla K áčma , Helena Velicho á, Lenka Fiše o á, Pa la Bu ešo á, Pa el T zník ABSTRACT The aim o his wo k was op imiza ion o he me hods o ace- and ul a ace analysis, such as ICP-OES, ETA-AAS o cha ing he esou ces o indi idual o ms o in in oods u s. Inc ease o he sensi i i y o he me hod o ICP-OES was achie ed using he echniques o gene a ion o hyd ides, which was also op imized. Based on he in o ma ion a ailable on he occu ence o he di e en o ms o in, i appea s ha many o hese o ganome allic compounds a e con ained in ma ine animals; a en ion has mainly ocused on o ganisms such as ma ine ish, c us aceans, molluscs and algae. Tin compounds o p edominan ly ino ganic o igin can be ound in oods and be e ages which a e packed in cans wi h a p o ec i e in coa ing, oo. The abo e men ioned me hods ha e been applied o he analysis o selec ed be e ages wi h low con en o in such as Coca Cola, Sp i e, Fan a, Gamb inus 10°, Powe King, and milk in he cans. Fu he mo e samples o animal o igin as Sa dines in oil, and Hun e 's salami we e examined, oo. P io o he de e mina ion o in, samples need o be app op ia ely modi ied o analysed. Decomposi ion o he samples was done in he mic owa e sys em. Low p essu e ion exchange ch oma og aphy wi h on-line de ec ion o ICP-OES was used o sepa a ion o ino ganic in compounds. Sepa a ion o o ganically bound in compounds was pe o med by HPLC on a column o ACE C-18, 3 µm, 15 cm × 1.0 mm wi h o -line de ec ion by ETA-AAS. All o he abo e o ms o in compounds can be sepa a ed wi h his column. Due o he imp o emen in he de ec ion o o ganically bounded in, HPLC wi h iden ical ACE C-18 column coupled online o example wi h ICP-MS o spec o luo ime y could be ecommended. Keywo ds: oods; in; specia ion o o gano in; HG-ICP-OES; HPLC-ETA-AAS INTRODUCTION One o he indica o s o he oxicological quali y o ood is he con en o oxic mine al compounds. Lead, cadmium, me cu y and a senic belong among he mos oxic elemen s. In highe concen a ions ace elemen s such as, in, ch omium, cobal , coppe , molybdenum, nickel, selenium, anadium, and o he s may show oxic e ec s. Fo hese elemen s, he maximum allowed quan i y, he pe missible maximum quan i y o special dose a e speci ied in ood legisla ion in he Czech Republic. Fo humans o o o he animals, in is an essen ial elemen , bu in la ge quan i ies i appea s as oxic. I s biological impo ance o humans has no ye been ully elucida ed; i is assumed ha i is indispensable o op imal g ow h and he o ma ion o blood. Tin compounds a e p ima ily loca ed in he Ea h's c us and also due o he human ac i i ies in he ai and wa e low. The mos dange ous o m o in a e he compounds whe e in is o ganically bounded in o ganome allic compounds. In spi e o i s po en ial oxici y, in is used in la ge quan i ies in plas ic and canning indus y and o des uc ion o pes s in ag icul u e, whe e i ge s in o ag icul u al p oduc s and om he e in o he ood. Toxic e ec s o in a e known, bu i s use is inc easing. Humans can abso b in om ood, du ing b ea hing, and h ough he skin. Abso p ion o in can en e human o ganism in he diges i e sys em, hus ood con ol has been emphasized qui e in ensi ely ecen ly. The a e age con en o in in he Ea h's c us is abou 3.0 mg.kg-1. In na u e, in occu s as he mine al cassi e i e (s annic oxide SnO2,) and as an ing edien in some sulphides. Me al in is an impo an componen o common alloys (b onze). The inpla e cans a e made o s eel shee s used in he ood indus y. Consump ion o inpla e in ood packaging is s ill g owing and he la ges sha e goes o he p oduc ion o cans o he dis ibu ion o bee and o he be e ages (G eenwood and Ea nshaw, 1993). A la ge quan i y o in is consumed o he p oduc ion o o ganome allic compounds. Tin is used as a componen o special pain s o ships and o he bodies subjec ed o he long- e m e ec s o he sea wa e . T ibu yl in compounds a e used o he p ese a ion o wood. T ibu yl in oxide Po a ina s o Slo ak Jou nal o Food Sciences Volume 13 370 No. 1/2019 O(SnBu3)2 is an excellen agen o p o ec ion o he wood. R3SnX is also used as an an imic obial agen o ex e mina e o slime mould in he pape and pulp. T iphenyl inace a e and iphenyl inhyd oxide a e applied in ag icul u e as ungicides. Fo example, Bu2SnOH and Ph3SnOAc inhibi he g ow h o ungi, such as po a o bligh and simila in ec ions, in suga bee , peanu s and ice. Tin also se es as a mi e-kille on apple and pea ees. O he R3SnX compounds a e e ec i e a killing insec s as chemos e ilan o by killing o la es (Velíšek, 1999). Dibu yldilau a e and analogue oc yl in compounds a e used as s abilize s o plas ics (PVC). The mos e ec i e s abilize compounds (R2SnX2 – R = oc yl-, X = lau a e, malea e). Fo he packaging o ood p oduc s, he polyme ic cis-bu enedioic and (Oc 2SnOCOCH = CHCOO)n and Oc 2Sn(SCH2COO Oc )2, wi h S,S´-bis (isooc yl-me cap oe hanola e), which is used in cases whe e a colo less, non- oxic, highly anspa en ma e ial is essen ial, we e app o ed. Ano he no less impo an applica ion o o gano in compounds is hei use as cu ing agen s in ulcaniza ion o silicone unde no mal empe a u e (G eenwood and Ea nshaw, 1993). On o he hand, he ino ganic o ms o in a e less oxic o human o ganism. Ino ganic in is jus di icul o be abso bed by he o ganism and is usually exc e ed in he u ine. Acco ding o he s udy om 1997, in (II) is mo e oxic han in (IV). Due o he p esence o humic acids in he g ound wa e s ha educe in (IV) on in (II) i s concen a ion is inc easing (Pawlik-Skow onska, Kaczo owska and Skow onski, 1997; Rüdel, 2003). Ino ganic in is no ca cinogenic o e a ogenic. Tin in all o ganic indus ial compounds is e a alen . O ganic alkyl o a yl g oups a e g oups ha a e co alen ly bonded wi h he cen al a om o in. Mono-, di- and isubs i u ed bu yl in, phenyl in, and hei de i a i es a e conside ed i s mos impo an compounds. The solubili y o o ganically bounded in compounds depends on pH, ionic s eng h and empe a u e o en i onmen . Deg ada ion o o gano in compounds occu s in bio ic o abio ic p ocesses. The ans o ma ion is simila o bo h cases (Rüdel, 2003) i leads h ough he dealkyla ion o dea yla ion on ino ganic in compounds (Hoch, 2001). The Eu opean Union (EU) limi s maximum le els o ce ain con aminan s wi h a iew o educe he con en o hese subs ances in oods a such a low le el, which is ye o be achie ed in compliance wi h he good manu ac u ing o ag icul u al p ac ices. The aim is o achie e a high le el o public heal h p o ec ion, especially o ulne able g oups o he popula ion: child en, alle gies, e c. (Commission Regula ion (EC), 2006). Tin ge s in o inned ood ia u he decomposi ion o he inne walls o inned ood cans. The decomposi ion o inpla e is dependen on he ood ma ix, pH, he p esence o oxidizing subs ances (an hocyanines, ni a es, ions o i on and coppe ), and he p esence o ai (oxygen) in he a ea o ood, ime and s o age empe a u e. Nowadays, co osion and dissolu ion o in cans will be supp essed by a a nish, which g ea ly educes he pene a ion o in in ood p oduc s. Tin cans con ain mainly canned ege ables, ui s, juices and o he be e ages, ui s in swee pickle, mixed ui s in b ine, canned milk and pickled mush ooms (Figu e1). Fo he de e mina ion o ace elemen s as well as o de ec ion o in in oods u s, i is necessa y o choose he analy ical me hods, which a e able o de ec e y low, ace amoun s o analy e. A omic Spec ome y me hods – a omic abso p ion, emission and mass spec ome y a e sugges ed o analyses o in in ood. The mos common me hod is a omic abso p ion spec ome y (AAS). When you use lame a omiza ion he limi o de ec ion is on he le el o 0.1 mg.L-1; using he elec o he mal a omiza ion e en dec eases his limi . Addi ional op ions o he de e mina ion a e ep esen ed by di e en ex ac an s (e.g. wi h hexane, oluene, chlo o o m me hanol), con e sion o he compounds in o ola ile de i a i es (by eac ion wi h G igna d´s eagen s o eac ion wi h NaBH4 esul in ola ile hyd ides usable o a omic abso p ion spec ome y de e mina ion) and sepa a ion by gas ch oma og aphy. I is also possible o use liquid ch oma og aphy wi h mass spec ome e wi h ICP (induc i ely coupled plasma). These me hods o e o many elemen s excellen limi o de ec ion, so hey a e sui able o he de e mina ion o ace amoun s o elemen s in biological ma e ials. Compa able esul s a e achie ed using sensi i e elec oanaly ical me hods, mainly a modi ica ion o pola og aphy and ol ampe ome y, elec og a ime y o luo escence. Fo he de e mina ion o o ganically bounded o ms o in, in pa icula o ibu yl in compounds (including deg ada ion p oduc s – di- and monobu yl de i a i es) a e also used he abo e me hods (AAS, ICP-OES and ICP- MS), in connec ion wi h sep aing in on-line o o -line a angemen (Figu e 4). To de e mine o al in de ec ion o di e en o ms (sepa a ion o ino ganic and o ganically bound o ms o in) is pe o med bo h ia comple e mine aliza ion o samples and in d y (combus ion and subsequen dissolu ion in acid) o we way (oxida ion eac ions in he s ongly acidic en i onmen ). Mine aliza ion by he we way can be u he pe o med unde he hood in an open o closed sys em. Mine aliza ion in a closed sys em can be done unde high o low p essu e and ei he common o Figu e 1 The mos equen ly obse ed ypes o canned ood on he in con en (Pe ing and Basic- D o zak, 2002). Po a ina s o Slo ak Jou nal o Food Sciences Volume 13 371 No. 1/2019 mic owa e hea ing can be employed (Made and Ču do á, 1997). I he de e mina ion o he di e en o ms o in is equi ed, ea men o samples keeping in compounds in hei o iginal o m is essen ial and also main aining hei ini ial ela ionship in he sample is c ucial. Fo hese pu poses e y gen le p ocedu es mus be employed. They a e based on he ex ac ion wi h helping o ul asonic wa e o wi h he suppo o many mic owa es in pH bu e ed en i onmen s. I he sepa a ion o isola ion o he indi idual o ms in one s ep is impossible, i is necessa y o use a mul i-s ep ex ac ion o speci ic ex ac ion o he con e sion o o he o ms, and hen mul i-s ep analysis mus be ca ied ou (Simon e al., 2002). Scien i ic hypo hesis Since he de e mina ion o he in compounds in oods is o g ea impo ance, pa icula ly in e ms o he occu ence o o gano in compounds ha accumula e in human adipose issue, many echniques ha e been used o his pu pose. S udies using di e en echniques, such as g aphi e u nace a omic abso p ion spec ome y (GF AAS) and cold apou a omic abso p ion spec ome y (CV AAS), ha e been epo ed. The induc i ely coupled plasma op ical emission spec ome y (ICP-OES), which makes i possible simul aneous de e mina ions on mo e di e en wa eleng h and allows apid an e ec i e analysis, is also epo ed. The design o expe imen s is an impo an app oach and has been success ully employed in sample p epa a ion p ocedu es o iden i y he op imum condi ions and selec he p opo ions be ween he eac an s, allowing a as e acqui ing o esul s, minimizing cos s and ime in ol ed. The use o dilu ed eagen s in decomposi ion o ex ac ion p ocedu es, which leads o media wi h educed acidi y and also dec eases he amoun o co osi e subs ances, is an example o he expe imen al design applica ion. Chemome ic ools we e used o es ablish he app op ia e expe imen al condi ions o de e mina ion o o al in con en by CV AAS o by hyd ide gene a ion a omic emission spec ome y wi h induc i e coupled plasma (HG ICP-OES) and combina ion o sepa a ion s ep (EC o HPLC) wi h he same me hods o de ec ion o de e mina ion o in (II) and in (IV) and o gano in compounds in biological samples. Thus, his pape pu pose is a mul i a ia e op imiza ion o an analy ical me hod h ough all pa ame e s ou side he de ice pa ame e s conclude selec ion he mos sui able wa eleng h, concen a ions o eagen solu ions, co ec ion o in e e ences and inle lows o gases and solu ions o de e mine he indi idual species o in employing ICP- OES. MATERIAL AND METHODOLOGY Ma e ial and eagen s All eagen s used we e analy ical g ade, and solu ions we e p epa ed wi h ul apu e deionized wa e ob ained om a e e se osmosis wa e pu i ica ion sys em and ul apu e sys em (Aqua Osmo ic 02 Tisno , CR and Pu elab ULTRA, Elga, UK). The ni ic acid (68%), hyd ochlo ic acid (37%) and hyd ogen pe oxide (31%) used we e o Analpu e Ul a (Analy ika, s. .o., CR). Ex e nal calib a ion was p epa ed om s ock solu ion o in o 1000 mg.L−1 (As asol®). Also, 1000 mg.L−1 s ock solu ions o gano in compounds we e p epa ed om dibu yl in dichlo ide (97%), iphenyl in chlo ide (95%) and ibu yl in chlo ide (95%), Sigma – Ald ich s. .o. CR and dilu ed acco ding o he wo king ange equi ed. The calib a ion cu es we e p epa ed in a sui able ange o concen a ions in acco dance wi h he pu pose. O he eagen s such as sodium e ahyd idobo a e NaBH4, NaOH, KOH o hyd ide gene a ion used and o ganic sol en s and acids (me hanol, ace oni ile, ace ic acid and ie hanolamine) we e HPLC g ade om Sigma – Ald ich s. .o. CR. The glasswa e used in he expe imen s was p e iously decon amina ed wi h a ni ic acid solu ion (10% / ) o 24 h (Dan as e al., 2013), subsequen ly washed wi h ul apu e wa e and d ied a oom empe a u e. Ins umen a ion Fo he analysis o he ood samples an induc i ely coupled plasma op ical emission spec ome e wi h axial iew (ICP-OES, The mo Ja ell Ash, IRIS/AP,USA) and an a omic abso p ion spec ome e wi h elec o he mal a omisa ion (The mo Elemen al, Solaa M6, UK) we e used, and he ope a ing condi ions a e de ailed in Table 1 and Table 2. Fo p epa a ion o samples o o al in con en analyses a mic owa e diges ion sys em MLS 1200, Miles one i was used and o sepa a ion o o gano in o ms an HPLC sys em (Dionex RS 3000 Ul ima e, USA) was used. Op imiza ion s a egy and analysis o he da a In o de o achie e he bes wo king condi ions p o iding he lowes de ec ion limi we e pe o med an op imiza ion, which includes he choice o he bes wa eleng h o in and app op ia e ins umen se ings. Sensi i e wa eleng hs o in ha e been selec ed om a da abase o TEVATM (The mo Elemen al Valida ed Analysis, ICP-OES so wa e, . 1.4.0. o con ols he op ical emission spec ome e wi h induc i ely coupled plasma). I was es ed a o al o six wa eleng hs, which is able o he in de e mina ion. O hese six wa eleng hs we e chosen wo (Table 2), which was he signal o in he bes esponse (SBR). O he pa ame e s we e se ing he inpu o he plasma on 1150 W, auxilia y gas low 1 L.min-1, he up ake o he sample o he nebulize 1.85 mL.min-1. S a is ic analysis Valida ion o analy ical me hod The p ecision o he me hod was e alua ed ia he epea abili y and can be exp essed as he ela i e s anda d de ia ion (RSD) o a se o measu emen s. Accu acy exp esses he di e ence be ween he alue ound expe imen ally and a e e ence alue. In his s udy, T ace elemen s in CRM ma e ial ish issue (NIES-11) was used o es ablish he accu acy h ough he alues calcula ed using he Eq. (1). This app oach is di ec ly ela ed o in e na ional s anda ds. Reco e y (%) = [ ound alue/ce i ied alue] x 100 (1) Po a ina s o Slo ak Jou nal o Food Sciences Volume 13 372 No. 1/2019 Whe e ound alue is he analy e concen a ion de e mined by he p oposed me hod and he ce i ied alue is he concen a ion alue o he analy e epo ed in he SRM ce i ica ion documen . The p ecision and accu acy exp essed as RSD (%) and eco e y (%), espec i ely, ob ained o he op imized analy ical me hod calcula ed on he ce i ied alues and he ound alues o CRM. The eco e y be ween he ce i ied alues and he ound alues anged om (87.0 ±1.0) % ( o ibu yl in) and abou (92.0 ±5.0) % o o al in con en , and he RSD alues ob ained we e be e han 5% (n = 3). The in con en in di e en samples o oods was measu ed by HG-ICP-OES. Samples be o e he de e mina ion we e decomposed in he mic owa e de ice by mine aliza ion s ep. As samples we e selec ed common be e ages: Coca Cola, Sp i e, Fan a, Gamb inus 10°, Powe King and picnic in he cans. I was also de e mined a o al con en o he in in caned Sa dines in ege able oil and in he hun e salami as a po en ial possible sou ce o o gano in compounds. Samples o d inks be o e mine alisa ion s ep in he ul asonic ba h we e degassed. Fo he decomposi ion o samples o be e ages and oods u s was ake up 10 mL o 1.0 g o samples and added 8 ml o HNO3 and 2 mL o HCl. A e his ope a ion he sample was e apo a ed o nea d yness, almos added o i 1 mL o HCl and olume was ill up on 10 mL. Values measu ed du ing bo h he wa eleng hs used a e lis ed in Table 8. The analysis o he da a ob ained om he expe imen al design was pe o med using S a is ica® 12.0 so wa e (S a So , USA). The measu emen s we e pe o med in iplica e and he da a a e exp essed as mean ±95% con idence in e al (CI). RESULTS AND DISCUSSION Op imiza ion o he hyd ide echnique The hyd ide gene a ion echnique was used o he educ ion o he limi o de ec ion. This echnique based on eac ion o NaBH4 wi h acid o p oduce hyd ogen, which gene a e ola ile hyd ide wi h sui able ions o me al. These ions a e hen ca ied in o he ca ie gas s eam in o discha ge o he ICP. I we compa e he di ec me hod o measu ing in and he hyd ide gene a ion echnique we can change measu emen ex en om he ange ppm (mg.L-1) o ppb (µg.L-1) le els. The op imiza ion o he concen a ion o sodium e ahyd obo a e o he hyd ide gene a ion o he co ec de e mina ion was pe o med. Op imiza ion o he concen a ion ange NaBH4 was selec ed on he li e a u e (Hosick, Ingamells and Macheme , 2002) whe e he op imum o concen a ion was abou 2.4% o NaBH4. The e o e, he op imiza ion o educing eagen s a concen a ions o 0.5; 1; 1.5; 2; 2.5; 3; 3.5; 4; 5% o he NaBH4 dissol ed in 0.1% KOH was pe o med. Simila ly o he acidi ica ion o he samples has been used 0.10; 0.25; 0.50; 0.75; 1.0 M hyd ochlo ic acid. As he mos sensi i e appea ed wa eleng h o in 189.989 nm (wi h he highes a io o in ensi ies (IR), which is he a io o ull in ensi y o he in ensi y o backg ound o blank on he same selec ed wa eleng h), he e o e he inal op imiza ion was ca ied ou and he inal esul s o p ocessing o he con en o in was exp essed only a his wa eleng h. The esul s o he op imiza ion s eps wi h a concen a ion o 100.0 ppb in a e p esen ed in Table 3 and Table 4. Calib a ion o hyd ide echnique o he de e mina ion o di e en o m o in The calib a ion solu ions o s anda ds o di e en o ms o in we e measu ed a wa eleng hs 189.989 and 242.949 nm. The concen a ion o he calib a ion solu ions was selec ed 50; 100; 150 µg.L-1 and as blank was used a 0.25 M solu ion o HCl. The calib a ion solu ions o Sn (IV) species we e p epa ed om s anda d calib a ion solu ion 1.0 g.L-1 in 0.25 M o HCl solu ion in o he 100 mL lasks. Calib a ion solu ions o Sn (II) we e p epa ed by loading he app op ia e amoun o SnCl2.2H2O. This amoun was ans e ed o 100 mL olume ic lask and ill up wi h deionised wa e . F om his s ock solu ions ha e been u he p epa ed calib a ion solu ions o he abo e concen a ion. E alua ion o he ope a ing condi ions ob ained o he ICP-OES This p ocedu e made i possible o selec he mo e sensi i e lines, ee o in e e ence (Table 1), ha we e used o calcula e he limi s o de ec ion (LOD) and he limi s o quan i ica ion (LOQ) h ough he backg ound equi alen concen a ion (BEC) and he signal- o- backg ound a io (SBR). The LOD and LOQ alues we e calcula ed using he BEC and he SBR, acco ding o In e na ional Union o Pu e and Applied Chemis y (IUPAC); BEC = Cs anda d / SBR, whe e SBR = (Is anda d − Iblank) / Iblank; Cs anda d is he e e ence elemen concen a ion in he solu ion; and Is anda d and Iblank a e he emission in ensi ies o he e e ence elemen and blank solu ions, espec i ely a he selec ed wa eleng h (Da Cos a e al., 2013, Schia o e al., 2009). The LOD was hen calcula ed as (3 × RSDblank × BEC / 100) and he LOQ as (3.3 × LOD), whe e RSDblank is he ela i e s anda d de ia ion o en measu emen s o he emission in ensi y o he blank solu ion. Sepa a ion o ino ganic o ms o in by ICP-OES me hod Ion-exchange ch oma og aphy Fo ms o in we e sepa a ed by ion-exchange ch oma og aphy wi h on-line de ec ion o ICP-OES. The measu emen was done by using he ime scan module in he TEVA so wa e. Be o e choosing a sui able so be is necessa y o ind ou as much as possible in o ma ion abou samples, which conside ed he p ope ies o he ma ix and he analy e, and based on his knowledge, hen choose he ype o phase and size o columns. O e o so ben s is simila as o illing o liquid ch oma og aphy. All so ben s, which we e used, had o be ac i a ed a i s . Ac i a ed so ben s unde educed p essu e using he so p ion appa a us we e implemen ed in polyp opylene columns. A e illing he columns we e washed up wi h deionised wa e . Tin in he compounds occu s in he o m ca ions Sn (II) and Sn (IV). The e o e ion change s we e selec ed as ca ion exchange s. The mos app op ia e ca ion exchange is like his he in ions a e ela i ely closely e ained and hey a e no washed up wi h wa e . Ano he impo an pa ame e is he selec ion o app op ia e eluen eagen s. Po a ina s o Slo ak Jou nal o Food Sciences Volume 13 373 No. 1/2019 Due o he s abili y o he plasma is no app op ia e use o elu ion agen s con aining highe amoun o o ganic compounds o high concen a ions o sal s. In wo k we e es ed exchange s Ambe li e IRC 50, Cellulose CM 23, Se acel CM 3, Dowex 50WX, T isac yl M CM and Sephadex CM 50 wi h elu ion eagen s 1 M HCl and 0,5 M NaOH. The mos o hem - Ambe li e IRC 50, Cellulose CM 23, T isac yl M CM and Sephadex CM 50 – we e sui able o sepa a ion o Sn (IV). Pe ec sepa a ion o Sn (II) and Sn (IV) ions is complica ed how is desc ibe in li e a u e (Whi e e al., 1998) ha he solu ions o sal s o Sn (II) ions a e e y uns able, easily oxidized by ai and especially on ligh . The e o e, he s udy was ocused on ime dependency o Sn (IV) con e sion on Sn (II) species on he ligh . In he p e ious chap e , i was ound ha when using a column illed wi h exchange Ambe li e IRC 50, in in he o m Sn (II) is washed ou a he sampling and Sn (IV) is e ained on he exchange and washed ou wi h 1 M HCl. This phenomenon was used o de e mining he ime con e sion dependency Sn (II) on Sn (IV) species. The unc ional ange o he pH o ion exchange which was used Ambe li e IRC 50 is 5-14, in o de o he pH o he sample is no need egula e. Resul s o measu ing dependences o peak a eas on ime in de i a ion and loga i hmical modes a e shown in Table 5 and Figu es 2 and 3. De e mina ion o in compounds by ETA–AAS me hod Op imiza ion o me hod Fo he de e mina ion o in in samples by elec o he mal a omisa ion in g aphi e u nace an ELC (Ex ended Li e Cu e e) and Sn hollow ca hode lamp has been used. Acco ding o li e a u e (Chen e al., 1996), whe e i was pe o med by op imizing he wo king condi ions o he de e mina ion o Sn by ETA AAS me hod. Fo backg ound co ec ion a Zeeman co ec ion me hod has been selec ed and as ma ix modi ie a combina ion o Palladium and Asco bic acid was used. The uni was se ing o he basic wo king condi ions ecommended by he manu ac u e (Table 6 and Table 7). Applica ion o op imized me hod o ood samples A e se inµ he op imal condi ions a calib a ion me hod o di e en o ms o in was pe o med. Calib a ion solu ions we e measu ed a a wa eleng h o 224.6 nm wi h calib a ion unc ions y = 0.0073x + 0.0502 and R² = 0.9977 o ibu yl in chlo ide; y = 0.006x + 0.0524 and R² = 0.9975 o dibu yl in dichlo ide and y = 0.004x + 0.0457, R² = 0.9962 o iphenyl in chlo ide. The concen a ion o he calib a ion solu ions 10, 30, 50 µg.L-1 has been p epa ed. A solu ion o 50 µg.L-1 o di e en o ms o in wi h he addi ion o 0.5 ml 65% HNO3 in o a 50 ml olume ic lask and added a mix u e o MeOH: H2O (40: 10) has been p epa ed om s anda d solu ions (Schia o e al., 2009). As blank and dilu ion solu ion 0.65% HNO3 has been used. As a ma ix modi ie a solu ion o Pd(NO3)2 and 1% solu ion o asco bic acid we e used. This mix u e wi h sample by au osample was sampled o he ELC o ETA AAS. Due o he imp o emen o he de ec ion o o ganically bound in and s eamlining o analysis would be sui able HPLC wi h column ACE C-18 connec in on-line a angemen , o example wi h ICP-MS o luo ime e (Gonzáles-Toledo e al., 2001). Table 1 Cha ac e is ics and ope a ing condi ions used o analysis by ICP-OES wi h axial iew. Pa ame e Cha ac e is ics Radio equency powe (W) 1150 Plasma gas low a e (L.min−1) 15.0 Auxilia y gas low a e (L.min−1) 1.5 Sample up ake a e (mL.min−1) 1.85 Nebulize gas low a e (L.min−1) 1.00 Nebulize ype Concen ic Sp ay chambe Type cyclone Replica es 3 Injec o ube diame e (mm) 2.0 Signal in eg a ion ime (s) 1.0 Wa eleng h (nm) Tin 189.989 242.949 Table 2 Wa eleng hs sui able o de e mina ion o in. Wa eleng h  [nm] Spec al o de ela i e in ensi y 189.989 136 150,000 242.949 107 100,000 Table 3 Values ob ained o BEC, LOD and LOQ in he analysis o liquid samples o be e ages by ICP-OESa. Analy ical pa ame e Sn(II) 189.989 nm Di ec me hod Sn(IV) 242.949 nm Di ec me hod Sn(II) 189.989 nm Hyd ide gene a ion Sn(IV) 242.949 nm Hyd ide gene a ion BEC (mg.L−1) 0.2185 0.9422 0.0298 0.0967 LOD (mg.L−1) 0.0036 0.0232 0.0006 0.0011 LOQ (mg.L−1) 0.0107 0.0697 0.0017 0.0033 No e: a Fo solid samples alues o LOD and LQD is necessa y mul iplied wi h ac o o mass o 1.00 g o samples and comple ed o 10.0 mL wi h deionised wa e and exp essed in mg.kg-1. Po a ina s o Slo ak Jou nal o Food Sciences Volume 13 374 No. 1/2019 Table 4 Dependency o in ensi y a ios (IR) on he concen a ion o NaBH4 in he solu ion. % NaBH4 IR % RSD 0.5 13.57 0.6973 1.0 32.95 0.8726 1.5 49.96 0.8841 2.0 64.77 1.3630 2.5 80.50 0.7996 3.0 90.37 0.6808 3.5 78.21 0.7758 4.0 73.77 1.6490 5.0 18.40 5.5600 Table 5 Dependence o he peak a ea a he ime by ICP-OES me hod in ime scan model. Peak a ea [s] Sn (II) Sn (IV) 20 6659.5 10211.0 420 2929.5 13678.0 780 1720.5 14204.0 1140 620.5 15217.0 1560 417.0 15450.0 1920 145.5 16006.5 Table 6 Wo king condi ions o de e mina ion o in by ETA-AAS me hod. Pa ame e Se ing Wa eleng h 224.6 nm Backg ound co ec ion Zeeman e ec Time o measu emen 3 s Sli 0.5 nm HCL cu en 75% Imax Table 7 Tempe a u e – ime p og amme o ETA AAS. Phase Tempe a u e [ºC] Time [s] Ramp [ºC.s-1] Flow o A [L.min-1] 1 100 30 10 0.2 2 120 10 50 0.2 3 800 20 150 0.2 4 2300 3 0 0 5 2600 3 0 0.2 Table 8 Con en o in in ood samples ob ained HG-ICP-OES me hod. c [mg.L-1] Sample 189.989 nm Coca Cola 0.1766 ±0.0629 Sp i e 0.0903 ±0.1159 Fan a 0.0275 ±0.0390 Gamb inus 10° − bee 0.0360 ±0.0100 Powe King 0.0227 ±0.0015 Piknik 0.3758 ±0.0078 Sa dines in ege able oil 1.0791 ±0.0892 Hun e salami 0.7016 ±0.1250 Po a ina s o Slo ak Jou nal o Food Sciences Volume 13 375 No. 1/2019 Figu e 2 Time dependence o con e sion Sn (II) on Sn (IV) – ime scan model. Figu e 3 Loga i hmical dependence o con e sion o Sn (II) on Sn (IV). y = -1445ln(x) + 11152 R² = 0.9846 y = 1230.3ln(x) + 6412.2 R² = 0.9868 0 2000 4000 6000 8000 10000 12000 14000 16000 0 500 1000 1500 2000 Peak a ea [s] Sn (II) SnIV SnII Sn IV Po a ina s o Slo ak Jou nal o Food Sciences Volume 13 376 No. 1/2019 CONCLUSION In his wo k we e simul aneously de eloped and uned he h ee pa s o he me hodology on he de e mina ion o di e en o ms o in in ood and be e ages. The me hod o de e mina ion o o al in con en in ood ma e ials by ICP-OES has been uned. Inc ease he sensi i i y o he me hod o ICP-OES was achie ed using he echniques o gene a ion o hyd ides, which was also op imized. Hyd ide gene a ion echnique educes he limi o de ec ion, so i can be used o samples wi h low con en o in. This me hod has been applied o he analysis o eal samples. Selec ed samples wi h low con en o in we e d inks Coca Cola, Sp i e, Fan a, Gamb inus 10°, Powe King and picnic in he cans. Fu he mo e, Sa dines in ege able oil, and Hun e salami. Simul aneously he me hod o sepa a ion o ino ganic o ms o in was de eloped and a op imisa ion has been used low p essu e ion exchange ch oma og aphy wi h on- line de ec ion wi h ICP-OES. As app op ia e ion exchange s shown ca ion exchange s Ambe li e IRC 50, Cellulose CM 23, whe e elu ion eagen was 1 M solu ion o HCl and T isac yl M CM, 50 CM-Sephadex, whe e elu ion eagen was 0.5 M NaOH solu ion. The bes esponse was on Sephadex ion CM 50. The peak was de ec ed du ing 40 seconds, and was su icien ly na ow and all. Simila ly sepa a ion o o ganically bound in was pe o med by HPLC on a column o ACE C-18 3 mm 15 cm × 1.0 mm wi h o -line de ec ion by ETA AAS. Elu ion eagen was degassed mix u e o ace oni ile- wa e -glacial ace ic acid wi h 0.05% ie hylamine (65: 23: 12) abou pH 5. All o he abo e o ms o in can a e wi h his column sepa a ed. Since he pe o med analyses (ino ganic o ms o in and o ganically bound in) and in o ma ion a ailable on he occu ence o he o ms o in, i appea s ha many o hese o ganome allic compounds a e con ained in ma ine animals, a en ion was necessa y mainly ocused on o ganisms such as ma ine ish, c us aceans, molluscs and algae. Based on hese indings and he esul s o his wo k on he op imiza ion o analy ical p ocedu es and he p epa a ion o samples o analysis (homogeniza ion, he selec ion o eagen s and echniques o he ex ac ion o indi idual o ms, o he modi ica ions, such as pH adjus men , adding speci ic eagen s, e c.) i will be possible o measu e samples o he ood and be e ages by using his me hodology ha a e c ea ed and op imized o he de e mina ion o he di e en o ms o in. REFERENCES Chen, H., Yao, W., Wu, D., B indle, I. D. 1996. De e mina ion o in in s eels by non-dispe si e a omic luo escence spec ome y coupled wi h low-injec ion hyd ide gene a ion in he p esence o L-cys eine. 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(In Czech) Whi e, S., Ca e ick, T., Fai man, B., Webb, K. 1998, Specia ion o O gano- in compounds using liquid ch oma og aphy – a mosphe ic p essu e ionisa ion mass spec ome y and liquid ch oma og aphy-induc i ely coupled plasma mass spec ome y as complemen a y echniques. Jou nal o ch oma og aphy A, ol. 794, no. 1-2, p. 211-218. h ps://doi.o g/10.1016/S0021-9673(97)00805-4 Acknowledgmen s: The esea ch was implemen ed unde he suppo o he ope a ional P og am called Resea ch and De elopmen o Inno a ions (Výzkum a ý oj p o ino ace) ha is co- unded by he Eu opean Fund o Regional De elopmen (ERDF) and also subsidized om he s a e budge o he Czech Republic wi hin he Cen e o Polyme Sys ems P ojec ( eg. n.: CZ.1.05/2.1.00/03.0111) and 2112 – Ins i u ional Suppo o he De elopmen o Resea ch O ganiza ions (Ins i ucionální podpo a na oz oj ýzkumné o ganizace). P ojec (ID 22738) subsidized by B no Uni e si y o Technology, g an ed by MŠMT. Con ac add ess: *Mi osla Fiše a, College o Business and Ho el Managemen L d., Ins i u e o Gas onomy, Bosonožská 9, CZ-625 00 B no, Czech Republic, Tel.: +420547218247, E-mail: ise a@ho skolab no.cz, Tomas Ba a Uni e si y, Facul y o Technology, Depa men o Food Analysis and Chemis y, CZ-762 72 Zlín, Czech Republic, Tel.: +420 576038084, E-mail: ise a@ .u b.cz ORCID: h ps://o cid.o g/0000-0002-8962-9280 S anisla K áčma , College o Business and Ho el Managemen L d., Ins i u e o Gas onomy, Bosonožská 9, CZ-625 00 B no, Czech Republic, Tel.: +420 547218247, E-mail: k acma @ho skolab no.cz Helena Velicho á, College o Business and Ho el Managemen L d., Ins i u e o Gas onomy, Bosonožská 9, CZ-625 00 B no, Czech Republic, Tel.: +420 547218247, Tomas Ba a Uni e si y, Facul y o Technology, Depa men o Food Analysis and Chemis y, CZ-762 72 Zlín, Czech Republic, E-mail: elicho a@ .u b.cz elicho a@ho skolab no.cz, Lenka Fiše o á, B no Uni e si y o Technology, Facul y o Chemis y, Ins i u e o Chemis y and Technology o En i onmen al P o ec ion, Pu kyňo a 118, CZ-612 00 B no, Czech Republic, Tel.: +420 541149424, E-mail: ise o a@ ch. u .cz Pa la Bu ešo á, College o Business and Ho el Managemen L d., Ins i u e o Gas onomy, Bosonožská 9, CZ-625 00 B no, Czech Republic, Tel.: +420 547218247, E-mail: bu eso a@ho skolab no.cz Pa el T zník, College o Business and Ho el Managemen L d., Ins i u e o Gas onomy, Bosonožská 9, CZ-625 00 B no, Czech Republic, Tel.: +420 547218247, E-mail: znik@ho skolab no.cz Co esponding au ho : *