baaaaae of its biologieal sionifiaaaee aad ita raaarkabla ability to...
Transcript of baaaaae of its biologieal sionifiaaaee aad ita raaarkabla ability to...
ptinelpul laorganie eoaal l laeat of feaaaa hones and teethe
Clangs to an iaomorphoos aerlaa of aabataaeea kaova as
•pat l ias* I t baa been tbe saHJeet of extensive iaveatigatioas
baaaaae of i t s b io logieal s ionif iaaaee aad ita raaarkabla
a b i l i t y to andargo a aariea of eat ioaie aad aaioaie axebaaga
raaetioaa, tbe er i t er ia for aaeb aa axafcaaga bslaa tlw
idaat i ty of ebarga sad the proximity of ionie radii of the
paira of ioas iavolvad. itaioag aaeb dlaarsa axebsage raaetlcns
a few bava attalaad aignifie«iaea dariag tba raeaat paat
eonsofiaaBt «pon tba tox i e i i y of tba aienaata involvedt aaab
sa axebaaga batag tba aaebaaiaai for ibair iaaorporatioa
tata tai«aa akatatat ayst«»* Baaed oa tba eoatftMporary
taportaaee glYsa to IHe toxie i ty eauaad by lead aad vaaadlaa
to tba baaiaa ayataa, atadiaa on tba replataaaat of ealalaai by
taad ( toa ie radii 0*99 aad 1*20 X ^apaet iva ly ) and of
pbaapbor«a by vanadina (Caraleat radii 1.10 aad 1.22 t
reepaclively) bava beaa eboaaa for tba preaeat tarest igat loaa.
I t la avideat tbat a eoieplata raplaeofseat of C|a IOM by 2*
Fb ioaa taada to lead pboapbate apat i te , ^^iQi^^^)^i^^)2*
vbi la tbat of <̂>?'* by yo^" teada to lead veaadata apat i te ,
Fb|Q(yo^)^ (^^}2« botb belag laMsorpba »t ealeims hydraxyl
iH»atite« A part ia l raplaaeaeat la aitber eaae laada to
fapaatloa of eel Id aalatloaa of tba eoaearaed ead'Haaabara*
• 2 «.
Xt liaa haaa aatabliahad that inhalation of laad
in the fora of daat or faaaa or I t a abaorptioa throngh tlM
•k ia laada to "lead poiaoalag** (Pluabian) vhleh i a , la
9aaaral« an oeeapatioaal dlaeaaa. I t la v a i l kaiHrn thai
load aalts are extaaaiireljr used in patrol to inprova i ta
ifaallty «id la pottery asd paiats raaaltiatp la eaataslaatioa
leadlRf thereby to a poasihi l i ty of iaeorporatlon of this
•leneat iato the haataa akeletal ayst^a. As ia the eaae of
lead the toxie effaet of Taaadias is ha»aa aysieai haa haaa
eoafiroted. Ia addlttoBt i t eoald be proved that a few
apeeies eoaiag under the siarine organiama are also valnerabla
to aaeh a t a x l e l t y . I t eoald be ahova that the priaeipal
pollttt iag aoarcea ot Tasadiaai are i t s preseneo In certaia
variet iea of ateel aa v a i l as the iadastr ia l establiaha«Bta
tavotviag the eleaent and i ta sotlts as eatalyata*
I t eoald be anwabigBoaaly established that iMia
laeerporatfid ta the ha»an skeletal system throanh exehttnga
raaetioaa oa ealettta hydroxylapatite of bones play a
• ign i f iesa t role ia tee priaeipal boae proecssos, aa»ely,
ea le i f i ea t ioa aad reaorptioa, the depositioa sad dissolutioa
respeetively of ealeias hydroxrlapaiite at the inte^rfaee of
bone aad body f l u i d s . €oRse(iaeatly» say attempt in the
tflreetioB of eliminatioa or aiaiesisattoa of aaeh a tex ie i ty
ta a8So<<'iatPd with a study of ih«> solubil i tT of ealeiaa
hydroxylapatite aa wall aa of the prodsata af the exehaage
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reae i i«aa m n i t o a v d above aader siaialat«d b lo loo iea l
eoBditioos*
f*roaipled b j aaeb a eonslderat loa tbe present work
vhieb deals a t t b the preparattoR, ebaraeter isat l^B aad
• o l t t b l l i t y e ^ t t i l i b r i a of lead phoaphaie a p a t i t e , lead
vaaadate i^patile aad a aer lea of e igbt of thd t r ao l ld
• • l o t l e n s apread over the e n t i r e eottpoait loaal raa«a, «aa
sudertakOB. Adoptiag eopree ip i ta t ion of tbe ead-iaeaibera
in acfueoua aedia threo^h a Jadleioas aiodif ieat ioa of tbe
e x i a t i n ^ methods, the sa«plea were prepared at 37^C to
• isralate b i o l o g i e a l eosd i t ioaa ,
Cbaraeter iea t ioa of tbese sanples vas hroaght
•%o«t tbroagb aopbtat leated ina tnmoBta l techsiqaea aaeh
•a X<-ray d t f f r a e t i e a , e lee t roas i ie roscop7, i . r . spectra l
• t ad iea asd thermogravlaietry in addlt ioa to tiMi eonveatloaat
ei i«alcal aaalyaea* Vegard'a lav de»aada that tbe a a i t e e l l
vol««e of a ser ies of so l id s o l a t i o ^ i vftrtes l i n e a r l y v i t b
Ibe eo«positiOR and o f fe rs a eonvealeat method of s e r a i t a i a i a g
i b e i r boaegeneity. As la to be expected f ron tbe bigger s i s *
of vaaadate l e a , a repIaeeiMBt of pboapbate ion by i t brlags
aboat a d t l a i t e a of tbe a a i t c e l l , A systeaiatie l i a e a r
depeadeaee of tbe un i t e d t l volaaea v l t h tbe pre;>ortiea of
vraBBdate loa rap lae lag ptkoapbaie lea obaerved l a tbe preaeat
• 4 -
•ariaa of aol ld aotations eonflrmad thatr hoao^aaeity* ''
The alactroa«}ierographB of a fe« rapraaaataiira aanplas
ravealed fha haxagonal paiiarn of the erystala eoaf imlag
iha abaaaea of axiraaaaaa phaaaa aad aaabling ar>proxiaata
ealealat ioaa of the mpteitie anffaaa araaa aad avaraf*
diaaaaioaa of the individual er jata la . Tha i . r* abaorpiiaa
apaetra eoald eoaf lm the Ideatity of tha aaaplaa* Tha
pradoMlaaat abaorption peaka raoorded la tha tr^cee of tha
awaplaa vara foaatf to be daa to the orthopheaphata aad
erthovanadate laaa. la additioa, tha i^aorptiaa paaka daa
to earbonata aad pyrophoaohata iaaa* tha two l lkatf
i vpar i t las , vara feaad to be abseat. Th<» abaenea af
earbonata ion altaiaataa tha paaslbilitjp of ataoapharla
iRteraetioB leodlnq to tha fornatioa of carbonate apatite*
Theniegraviaetrie aaalysis iadleated that a tavparatura of
300*V: ahoaan far driving oat vo la t i l e lMp«rltl*a froa tlia
aaaplaa,dld not i a f l l a t a eheaical deeoapoaitioa on thea.
Stadtaa on the a o l a b i l l i y of tha aaaplaa vara
aadartakaa at 97*C la order to laTaatlgata Ita dapaadanea
aa the raplaceaaat of f o . ion by ?0. Ion oa lead phoaphaie
apat i t e . Siaoe It vaa intended to deteralae tha aolubi l i ty
predaet of aaeh atapta froa data raaaltlag frme the ehaalaal
aaalyaea of the aatarated aolntion, a bnffered difisol\ing
aadtaa vaa aaad to aa lata ia eeaatasey of tha aat iT i t j of 0B'*1OM
« s •
tstrolved in saeh esleulstlons. la orddr to tnvostiaste tho
roprodQelbillty of tl» solubility prod«ets so detemiBod, tho u
stodios in oaeti esse ver« extended to s fow ehosen p trolnosy
tho rflUi0O bo lag rostrietod oaly from 2.0 to 2«7, sinee there
vas a aarkod f a l l ia the so lab l l i ty of a l l tbe 8«a;>les at p
l i l a o higher thaa 2 .7 , In addlt ioa, a l t aaeh haffared
tfiaolviag «odia wore aiaiataiaed at a aa tar l ty af 0.165 with
roapoet to aodiaa chloride to sisalate bielodieal eonditions,
Sy adopting aaeh a nedlaa of di«@olutioa the eoaplieated
proeesa of oralaating acearatoly the aet lT i ty eoeff ieieata
of polyvalent ions eonld ho avoided by aa«n«iBg a l l of thoa
to be uaiiy vlfchout foregoing aeearaey* I t is evident that
aaeh ealealatioaa aake tho aotah i l i ly prodaet. ff. » sad the
iealc prodaet, K. » aynonyaooa*
Eaeh one of the po«tfa»a4 oaaplaa «aa aipii l ihralad
« t t h tha ehoson baffer cMiblnatioa aa the aediaa of
diaaolatioB at a eontrotled rate of shaking uaiig a constant
taa^aratara ahaker'>hath« The eol loidal eoapoaoat of the solate
praaont ia i t s satarAted eolation dae io i ta lo« aolubi l i ty
wm» aeparated by f i l t r a t i o n at 37**C through a IGd aintered
f laaa eraeible before the solatitwa were aaalyaed for the
prodnets of diaaolutloa* A separate expdriment eonld prove
tha a a i i a b i l i t y of aaeh eraeibles for eol loidal separation*
Vhile phoar>horas and vanadlaa vera deterained
- 6 •
ee lor lne i r tea l l j y e«iipl«x<NM»lry ««• adopted for tko
determinalloa of lead, the attainable aeearsey la a l l %tm
oaaea being aerattalsod by aaaiyaia of oolvttoaa of koova
eorapoaltioaa*
A oorntiay of attatnMent of aataraticMn and tkO
aiataniM period of equll lbratioa r e h i r e d for the parpoae
wore dotemised tbroagh dlasolntloa Kiaotiea of a eeaple of
roproaoatativo amples, from aaoag tbe ooaeeatratloaa of tiM
prodaeta of di««ol«t loa, the aoaaarod tota l dlasolved
pfcoapboma vaa aabdl^lded Into tbe propertioaa of
orthopboopiiorle aeid aad i ta three diesoeiatioa prodaeta,
RJPO^ , WO. aad FO. aaing tbe tkree dtaaoeiatioa ooaataata n
of the aeld aad tbe oifailtbrlnn p of tbe airateM, tbe ta t ter
being repaired also for evalaating OH*" Ion eoaeeatratioa
aoeded for tbe ealoalatioa of aotabl l i ty predaot*
There exiate aa aMbigaity ta tbe ear l ie r IStArataro
rogardiag tbe aolute phaae l ike ly to eontrol the eolubi l t ty of
apatite ayateaa i lnoe tbe diaaolatlMi iavolTod ia bydrolytie*
That tbe apatitea exhibit atoiehiosetrle dtaaolatioa eonld not
aaaHblgaooaly bo oatablished by the ear l ie r workers, la order
to iareatigato thia aignlf ieaat aapoot of dteaotatioa of
apat i tee, the aolabi l i ty data of the preaeat Inveetigationa
wore aabjeeted to ealealatioaa to eatabltab vhieb waoag tiM
1 t
• f •
paaatbla pkaaaa axlitl»lt«d a eanatfwer far iha aet lTt ty
prodaet of i t a iona. i t la avidant i lwt far tfoa plieaphata
••tttalttiBg i^at i tea aseft phaaaa ara tHa pr i«arf «•<! aaeondary
phaapkataa af tke e^tal eoneanied ia addftioa to tha apat i ta .
By analogy with a deabla a a l t , Ca2(ttP0^)(6R)2t a piiaaa
r«portad to eenlrol tb«'> aolubi l i ty predaet af aaleiaa
bydraxylapatita hy faaetloaing aa a aerfaee eeatlag* tlM»
ianle predaat of i t a load eoaatarpartyPto2(*'*^4)^^*'')9* * * * alaa
•alaatatad for tha praaaai ayatma. Exwainatioa of the data im
ao lab i l i i y af a l l the phaaaa naatioaad abava ravaala that ike
ioale prodaet of i^^atita ahovad a eonaiaaey over the aat ira
p ranoa ia ' taai i faiad aad the ealealatad aat of valnaa ware
faaad to l i e v i th ia tha error l i is i ta* I t ia evident that iha
eorreapondiag vaaadate phaaaa are raiavant far lead rwiadata
i ^ a i i i a vhi le tha phaaaa af both pboaphate md vaaadata ara
io be eonaidered far the ayatena iavolving the ao!id aolntioaa.
Saeh ealealatioaa aare done ea the data of aolubi l i ty of a l l
tkaaa aaaiptaa. That the apatite phaaa ew»tralled the aa lab i l i t y
vaa farther aapplaoeated by the faet that tha g aioa ratta»
Pb/(F^V)» of the? aataraled aolatioaa of a l l tha aaaplaa vaa
ta the proxitaity of the theoretiaal valaa (1*67) eonflrsiag
•aaabigaoaaly ataiahioaiatrie diaaoluti^B of apati tea. Aat r
addltioaal attbataatiatloa of thia fact vaa that the p ip valaaa
• f tlM aaaplaa arare foand ta be anaffeated by the addition of
tea iosa*
8 - • -
I t <o«ld b« OBtabllshod fsrtlier that tho
• o l a h i l i t y product of oaeh aaaiple of th* aarioa whila
roaaislaff eoBstsnt at a l l the p valaaa iaveatigated^
iaareasad ayatettatteally vttti aa inera««a ia the e<taat
of raplaeoaeat of FO. by ro]: • Aa iatorpretatioa of thoaa
raaalta eoald be presided by the eoaeept of sltoratioaa
ia l a t t i e o and hydratioa oaargiaa of loaie eryatal«
eonaoqaoat apoa iao8tor^he«a aabatitatloa*
^..
/r-
- 9 - 9
%^ A«S« PMiaar, e l t « d la <*PkoaphorBa and i t s Cini{»o«atfa*', ? • ! • XI» t d i t « d hf J . f t . r«a l a s e r , l a i e r a e l m e a Pttbl laftera, Xne. , ffaa Yorfcf pp* 1439-39 <196|}»
S* » • M a l l « r , » • ! « • ClitM* A9ia» 30 , 2069 ( 1 9 4 7 ) .
$* t »A . Roblaaaa, 4 . 84Hi« aat Jotat S a r g . , 34 , 389(1952) .
• # A .S , Foaaer, "Cbanleal sad Pkyaieal Naiare of Hoaa t l iaara l * * , (A tav i t f * Praa«at«d at a Canfaraaea held at Vftalilagtoa, i } . r . l a 1968) ( C . A . , 7 6 , 31276 t , 1972 ) .
8 . A. Kaapp«aat» NataralaaeaaeHaftaa, 43 , 477 ( 1 9 5 6 ) . ( C . A . , S3, 16217, 1959) .
4* e . Rayak* H . Maaaaely, s, Raaaaaiaafal aad B, Kr ianar , Maaa tMh. Cheia., ^ , 249 ( I 9 6 0 ) ( C . A . , 54 , 20599, I 9 6 0 ) .
7 . V . Boifd., "A Taxt-Boofe of Pa iho lagy* , Laa rabtgar* P h i l a d e l p l i l a . pn, 428«29 (1962 ) *
• • Madhn P h a l l timti ? ,^, Nigaa* Ttia Tox ic i t y of 8 io lo0 lea l l3r Eaaani la l and ^««-E«sant la l E laaaata , ladlKa J . Clias. 22 -28 , B ( 1 9 8 1 ) .
f . T . S . B . fTarMaraJa, R.P. Siagb aad V.L. I f . t a a , J.laorg. Nael* ClMa., 3<|, 2072 (1972).
'I
19. H.L. Waahbara aad M.J. Shaar, 4. Sial. Cbaai.,ff li, 99 (1932)
II. Arthar f. ?og«l, A. Tazt noak of Qasatltattva Taargaalt Aaalfaia laeladlag Eleataatary Inatraaaatal Analyaia, Third Fdlllos, P443, Rngllah taagaaga Sook Soeleif* Laa Prleed Taxt Hoak <196|).
13. €.J. tavlaakaa aad «.r« Maaaan* J« Pbya* Cbaa., 99, 164 (19S5).
13. J . S . C l a r k , Caa .J .Cbea . ,33 , 1696(1985) . .^^m\
n^ii 14* a . l i . t e a t a r a , f . t . D ia ls and F . 6 . Carpaatar / u i \.--^ J . C a l l a t d . S a . , JX • *''^ ( 1 9 6 2 ) . r^^ -v ^t?
1 9 . f . I . La l f a r , J . Pbya. Chaa, , 66 , 973 ( 1 9 6 2 ) . 4*w. cv