范文一：渗透压计算

阐述溶液张力的概念及计算

张力是指溶液溶质的微粒对水的吸引力,溶液的浓度越大,对水的吸引力越大。

判断某溶液的张力,是以它的渗透压与血浆渗透压正常值(280~320mosm/L,计算时取平均值300mosm/L)相比所得的比值,它是一个没有单位但却能够反映物质浓度的一个数值。

溶液渗透压=(百分比浓度×10×1000×每个分子所能离解的离子数)/分子量。如0.9%NaCl溶液渗透压=(0.9×10×1000×2)/58.5=308mOsm/L(794.2kPa)该渗透压与血浆正常渗透压相比,比值约为1,故该溶液张力为1张。

又如5%NaHCO3溶液渗透压=(5×10×1000×2)/84=1190.4mOsm/L(3069.7kPa)该渗透压与血浆正常渗透压相比,比值约为4,故该溶液张力为4张。

对以上复杂的计算过程,不要求学生掌握,但要记住张力是物质浓度的一种表达方式,其换算自然亦遵循稀释定律:C1×V1=C2×V2。

然后列出课本上已标明相应张力的几种常用溶液:

10%(NaCl)11张(临床上可按10张计算)

0.9%(NaCl)1张

5%(NaHCO3)4张

10%(KCl)9张

10%(GS)0张(无张力,相当于水)

并指出,临床上多数情况下就是用以上几种溶液配制成其它所需的液体进行治疗,只需记住此几种溶液的张力,便可灵活自如地进行配制与计算所需溶液及张力;而不必去追究为什么10%NaCl张力是10张这一复杂的计算过程。

举例说明混合溶液张力的计算

例2、10%NaCl(10ml)+10%GS(90ml),请问该组溶液张力。

同学们很快能够根据C1×V1=C2×V2列出算式:10×10=X×100,X=1张

例3、10%NaCl(20ml)+5%NaHCO3(25ml)+10%GS(255ml),请问该组溶液张力。

10×20+4×25=X×300,X=1张。

例4、欲配制一组300ml,2/3张液体,现已使用5%NaHCO3(15ml),还需

10%NaCl多少毫升。

10×X+4×15=2/3×300,X=14ml

那么,再加入10%GS271(270)ml后即可配制成所需液体(300-15-14=271ml,GS为0张)

5、2∶1等张液是抢救休克时扩容的首选溶液,其有固定组份,由2份等渗盐溶液+1份等渗碱溶液配制而成。学生对配制2∶1液感到十分困难,为了便于学生记忆,快速计算、配制,便给出一个简单的计算公式(推导过程较为复杂,不必阐述)

配制2∶1液Mml,则需

10%NaCl=M/15ml————a

5%NaHCO3=M/12ml———b

10%GS=M-a-bml

例5、配制2∶1液300ml,需10%NaCl、5%NaHCO3、10%GS各多少毫升。 10%NaCl=300/15=20ml

5%NaHCO3=300/12=25ml

10%GS=300-20-25=255ml

这样,似乎很玄的2∶1液通过一个简单的公式便可快速配制出来。

范文二：血浆渗透压计算

血浆渗透压计算（mmol/L)

仅供参考

①（Cl-+HCO3-+20）×=mmol/L

正常值280~310mmol/L（平均300)

310mmol/L为高渗

②（Na++K+）×2+BS+BUN=mmol/L

（正常人：BS（blood sugar，血糖）为3.9~6.1mmol/LBUN（blood urea nitrogen，尿素氮）为1.78~7.14mmol/L)

正常值280~310mmol/L

310mmol/L为高渗

③MCV（平均红细胞体积μm3）=红细胞比积×1000除以红细胞数（N/L） 正常值82~96μm3,>96μm3为低渗，

④血清钠正常130~150mmol/L（平均140）

150mmol/L为高渗

⑤（Na++10）×2，正常280~310mmol/L（平均300）

310mmol/L为高渗

⑥Cl-+HCO3-=120-140mmol/L

140mmol/L为高渗

⑦血浆胶体渗透压有关计算公式：

血浆总蛋白g/L×2.41×2=289.2~385.6mmol/L

385.6mmol/L为高渗

⒈74×Ag/L+1.205×Gg/L=85~131.85mmol/L

例如白蛋白50g/L，则1.74×50+220=307mmol/L

范文三：渗透压计算

New Microcapsules Based on

Oligoelectrolyte Complexation

ARTUR BARTKOWIAKa AND DAVID HUNKELER

Laboratory of Polymers and Biomaterials, Department of Chemistry, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland

ABSTRACT: A new one-step microencapsulation procedure has been devel-oped. For the alginate/oligochitosan system the molar mass of the chitosan is akey parameter in the formation of stable, elastic capsules with high modulus.Furthermore, the selection of an optimum molar mass provides an additionaldegree of freedom, permitting the simultaneous regulation of mechanical prop-erties and permeability without the need for multicomponent organic-inorgan-ic chemistries as have been previously employed. The effects of molar mass ofchitosan, its concentration, the alginate molar mass and its metal salt on thepreparation, physical properties, and release characteristics of the capsuleshave been studied.

INTRODUCTION

Over the past two decades a variety biologically active species have been immo-bilized or encapsulated, ranging from enzymes for bioreactors and biosensors1 tohepatocytes for the treatment of liver failure.2 Microencapsulated cells, in general,have potential for the treatment of diseases requiring enzyme or endocrine replace-ment as well as in nutrient delivery of enzymes and bacteria. Encapsulation is, fur-thermore, employed in various industries including food,3 agriculture,4 andbiotechnology, 5 the latter of which is clearly a high value-added application. A par-ticular case of encapsulation involves immunoisolation of mammalian cells for thegeneration of bioartificial organs.

A wide variety of approaches, based on various polymer chemistries, processesfor membrane formation and encapsulation technologies have been evaluated. Thesehave been summarized in a recent review.6 Other than some innovative chemistriesintroduced by Sefton7 and Dautzenberg,8 who employed, respectively, phase inver-sion and complex coacervation to form the capsular membranes, the overwhelmingmajority of the literature over the past two decades has utilized the alginate/poly-L-lysine polyelectrolyte symplex system.9 Generally, multivalent ions such a calciumor barium are used to gel the alginate. These solid beads are then coated with a so-lution of an oppositely charged polyelectrolyte (poly-L-lysine). The beads are con-verted into a permeable capsule by liquefying the gel, usually via the addition of thechelating agent such as ethyleneditetracetic acid or sodium citrate.

While Sun, who pioneered the alginate/poly-L-lysine chemistry,10 was success-ful, originally in rodents and more recently in larger animal discordant xenografts,a e-mail: Artur.Bartkowiak@epfl.ch

36

BARTKOWIAK & HUNKELER: NEW MICROCAPSULES37many authors have failed to repeat his results. Further disadvantages of the alginate/poly-L-lysine system include the present cost of the polycation and the limited me-chanical properties and biocompatibility reported by some groups.11 Moreover, thereproducibility of the capsule properties of both polymers is still questionable, ow-ing to the batch to batch changes in properties. Therefore, modification of this chem-istry has been extensively investigated, where metal cations other than Ca2+12 and poly(amino acids) other than poly-L-lysine13 have been employed. Poly-L-lysinecan be also replaced by other polycations, with the chitosan found to be a good sub-stitute. This natural occurring polysaccharide exhibits various biological activitiesand many attempts have been made to apply it as a biomaterial.14

They are many “so-called” chitosan/alginate capsules described in the academicliterature, 15 with the first attempt to replace poly-L-lysine with chitosan having beenreported by Rha et al. in 1984.16 Such capsules can be produced by a one-step pro-cedure, where alginate is dropped into the calcium/chitosan solution, or in two stepswhere alginate/calcium preformed beads are subsequently coated with chitosan.15Several of the preparation methods for preparing alginate/Ca2+/chitosan capsuleshave been patented.17–19 However, all techniques employ high molar mass polymers(greater than 10 kD) with reactions carried out below a pH of 6.6 to ensure chitosansolubility. Furthermore, the replacement of PLL by chitosan does not significantlyimprove capsule mechanical properties nor does it permit the control of membranemolar mass cut-off.

The capsule membrane formation involves a salt bond formation between two op-positely charged polymers during the diffusion of chitosan macromolecules into thewide pore alginate/Ca2+ gel bead matrix. However, in the absence of the addition ofcalcium cations, very thin and fragile membranes are formed owing to the slow dif-fusion of polycation. The authors believe that this limitation can be overcome by em-ploying a lower molar mass chitosan, in analogy to the cellulose sulfate/pDADAMCsystem introduced by Dautzenberg.8

The objective of our investigation has been the evaluation of the effect of chitosanmolar mass (<100 kd)="" on="" mechanical="" properties="" and="" permeability="" of="" binary="" alginate/chitosan="">

It will be shown in this paper that the control of the molar mass (MM) of the poly-electrolytes is a key parameter in the formation of stable capsules.20 Furthermore,the selection of an optimum MM provides an additional degree of freedom to the bi-nary polyelectrolyte complexation, permitting the simultaneous regulation of me-chanical properties and permeability without the need for multicomponent organic–inorganic chemistries as have been previously employed.

EXPERIMENTAL

Materials

Alginate

Alginate Keltone HV (lot. 46592A: Mn = 300 kD and polydispersity of 2.3) wasobtained from Kelco/NutraSweet (San Diego, CA, USA). Molar masses were in-ferred from (gel permeation chromatography) measurements on a Shodex OHpak

38ANNALS NEW YORK ACADEMY OF SCIENCESSB-804 HQ stationary phase using 0.1 M aq. Na2SO 4 as a mobile phase. A relativecalibration curve based on pullulan standards (PSS, Mainz, Germany) wasemployed.

Chitosan

Chitosan samples with different molar masses (1–100 kD) were obtained in con-trolled radical degradation by hydrogen peroxide (0.8–6.4 mMol/g of polysaccha-ride) at 80°C 21,22 of chitosan HMW (Aldrich, Buchs, Switzerland, Lot. 06026MNwith degree of deacetylation 86.2%). Molar masses of chitosan samples were esti-mated by GPC measurements using the Shodex OHpak SB-804 HQ and 0.5 M aceticacid/0.5 M sodium acetate buffer system, which is recommended by Showa-DenkoCompany (Tokyo, Japan).23 Pullulan and polyethylene glycol standards (PSS,Mainz, Germany) were used for column calibration and as relative references forMM calculation. All other reagents were of analytical grade.

Microcapsule Preparation

Capsules were formed from a pair of oppositely charged polysaccharides, wherea 0.75–1.5% aqueous sodium alginate was prepared in deionized water, 0.9% NaCl,or a 1% aq. mannitol solution. Approximately 2 mL of this solution was introducedinto a 5 mL disposable syringe with a 0.4 mm flat-cut needle (Becton Dickinson AG,Basel, Switzerland). The droplets were sheared off for 30 sec (kdScientific syringepump, Bioblock Scientific, Frenkendorf, Switzerland: flow rate 1 mL/min) into 20mL of 1% chitosan (molar mass varied between 1–100 kD) solution when the pHwas adjusted to 6.5 with 1 M NaOH. The microcapsules produced (1–3 mm in diam-eter) were allowed to harden for 30 minutes, filtered and rinsed with solvent used forpreparation of polysaccharide solutions. Each process was repeated 3–4 times withcollected microcapsules (more than 2 mL in volume) stored at 4°C. The entire cap-sule formation procedure described herein has been performed at ambienttemperature.

Permeability Measurements

Two mL of microcapsules were placed in a 10 mL recipient bath. Two mL of a0.1% polymer standard solution (glucose plus four dextrans 4–110 kD), in 0.9%NaCl, was added under agitation. Aliquots were withdrawn at various times and in-jected into a liquid chromatograph equipped with a Shodex SG-G and SB-803 HQcolumns. The eluent was 0.9% NaCl applied at a flow rate of 0.5 mL/min. The poly-mer concentration was proportional to the height of the detected chromatographicpeak and solute diffusion was calculated with respect to the initial standard concen-tration. In this study the cut-off of microcapsules was defined as the lowest molarmass of dextran for which solute diffusion was smaller than 2% after a contact timeof 32 minutes.

Mechanical Characterization

Microcapsules were tested on a Texture Analyzer (TA-2xi, Stable Micro Systems,Godalming, UK). The apparatus consists of a mobile probe moving vertically at aconstant velocity. The capsules were compressed at 0.1 mm/sec speed until bursting

BARTKOWIAK & HUNKELER: NEW MICROCAPSULES39

FIGURE 1. Mechanical properties of alginate/chitosan capsules as a function of thechitosan molar mass.

occurred. The force exerted by the probe on the capsule was recorded as a functionof the displacement (compression distance), therefore leading to a force vs. straincurve. Twenty capsules per batch were analyzed in order to obtain statistically rele-vant data.

RESULTS

Chitosans of various molar masses were prepared by controlled radical degrada-tion method using continuous addition of hydrogen peroxide at 80°C from 0.5 to4hours. All samples have similar polydispersity of MM (1.5–1.6) and degrees ofdeacetylation (80–84%).

The effect of chitosan molar mass on the relative mechanical strength of the pre-pared chitosan-alginate capsules, measured by their bursting force, is illustrated inF IGURE 1. Mechanical properties of capsules are strong function of the chitosan mo-lar mass. Below approximately 600–1000 daltons, precipitates are formed (no mi-crocapsules). In the few seconds after the reaction the alginate drop surface iscovered with a milky, non-transparent, unstable membrane, which during the reac-tion transforms into the white precipitate. Apparently, the oligochains (2–6 mono-meric units) are to short to react with more than one alginate chain and, therefore,do not function as crosslinkers and consequently do not create stable membranes.Above a molar mass of 30 kD the membranes are quite thin and have weak me-chanical properties. Generally capsules are so fragile that after removing the sur-rounding solution they rupture under their own weight.

Dautzenberg et al. described membrane formation of two oppositely chargedpolyelectrolytes as a two-step process.24 This begins with the spontaneous creationof a solid-like precipitate at the droplet surface as the result of the phase separationprocess. After this initial step the inner-direction build-up of membrane is observed.This process is diffusion-controlled, where the polycation penetrates through themembrane formed in the first step. When the cut-off of the primary membrane is toolow the polycation molecules are not able to diffuse through. This is the case when

chitosan of molar mass higher than 30 kD was used.

40ANNALS NEW YORK ACADEMY OF SCIENCES

FIGURE 2. Influence of reaction time on alginate/chitosan capsule mechanical resis-tance (chitosan 2.5 kD, reaction time 5–20 min, 1.25–1.75 mm in diameter). The verticalline refers to the “osmotic imbalance” between solution interior and exterior to the capsules.The horizontal lines in the “box ” represent the average values of the bursting forces.

Between the molar mass extremes mentioned above, stable capsules are generat-ed with a maximum strength at a chitosan molar mass of 2000–3000 daltons. Thecapsule mechanical strength is one of the most important features for practical pur-poses. With reduction of the chitosan molar mass below 30 kD, the formation of cap-sules with increasing membrane thickness and mechanical properties is observed.Similarly the molar mass of chitosan employed in the encapsulation procedure wasdetermined to by a key factor in the alginate/Ca2+/chitosan capsule formation.25However, in that case the optimum molar mass for stable capsules formation was inthe range of 160–330 kD. This difference is caused by immobilization of alginate bycalcium cations in the form of porous gel matrix. The decrease of membrane stabilityobserved for molar mass below 2000 is a consequence of the participation of precip-itation process in alginate/chitosan membrane formation.

All reactions described in this paper were carried out at pH 6.5, which is a limitof chitosan solubility. However, oligochitosans below 8–10 kD are soluble abovepHs of 7.0. The new binary capsules with good mechanical properties can be formedup to a pH of 7.4, which will be detailed elsewhere.26 The ability to produce capsules

under neutral and slightly basic conditions is a strong advantage of the newly devel-

BARTKOWIAK & HUNKELER: NEW MICROCAPSULES41

FIGURE 3. Mechanical resistance of capsules prepared in pure water and 1% mannitol solution (chitosan 2.3 and 2.5 kD, reaction time 10 min, 1.25–1.75 mm in diameter).

FIGURE 4. Comparison of bursting forces of capsules with different diameters (chito-san 2.5 kD, reaction time 10 min).

oped method, since the alginate/Ca2+/chitosan-based capsules can only be produced

up to a pH of 6.6. Since several types of biologically active species, including mam-

42ANNALS NEW YORK ACADEMY OF SCIENCES

FIGURE 5. Diffusion of dextrans through an alginate/chitosan capsule membrane.Comparison of capsules obtained with chitosan of different molar masses (reaction time30min). The ingress was measured after a contact time of 32 min.

malian cells, require a pH range between 7 and 7.4 for culture, the new encapsulationprocedure described herein is evidently much more robust over a practical range.

The mechanical properties of the capsules vary remarkably as a function of thereaction conditions. The molar mass of chitosan, and the reaction time, have beenfound to be of the greatest importance for the process of capsule formation. Gener-ally, the mechanical strength of the capsules increases with progressing reaction timeowing to the growth of the capsule wall thickness (FIG . 2). The significant drop inmechanical stability and surface deformation after ten minutes of reaction are the re-sult of differences in osmotic pressure between solution interior and exterior to thecapsules (osmotic imbalance). The wall morphology not only changes according tothe progressing conversion of the polyelectrolytes, but also because of the osmoticeffects caused by the counterions of the separated polyelectrolytes. A reduction ofthe capsule volume due to the osmotic draining of water plays an important part incapsule stability and porosity. This negative effect can be reduced by introductionnon-reactive low molar mass osmotic pressure modifiers such as mannitol. The cap-sules synthesized in the presence of 1% mannitol solution have improved mechani-cal properties (FIG . 3) with the mechanical strength depending strongly on the sizeof the capsules (FIG . 4). Larger capsules with higher volume/surface ratios are lessresistant than the smaller capsules.

Porosity, like mechanical resistance, depends on the thickness and morphology

of the capsule wall. Lower cut-offs are obtained after longer reaction times and using

BARTKOWIAK & HUNKELER: NEW MICROCAPSULES43

FIGURE 6. Diffusion of dextrans through an alginate/chitosan capsule membrane.Comparison of capsules prepared in water and in salt solution (chitosan 4.5 kD, reactiontime 30 min). The ingress was measured after a contact time of 32 min.

chitosan of higher molar masses (FIG . 5). For the chitosan of 4.5 kD the membranemolar mass cut-off is approximately 70 kD while for a chitosan of 7 kD it is 110 kD.Surprisingly, no significant difference in the permeability of alginate/Ca2+/chitosancapsules, prepared with chitosan of the Mv = 160–310 kD, was observed.25The presence of the low molar mass salt (0.9% NaCl) during the binary capsuleformation accelerates the diffusion of the oligocations and leads to thicker capsulewalls. Therefore, the capsule has less stability and a more porous membrane (FIG .

6). This difference can be explained by shielding effect of the sodium cations duringthe polyelectrolytes complex formation. At low alginate concentration the mem-brane growth occurs more rapidly than at higher concentrations. The oligocationscan penetrate more easily through less concentrated polyanion solutions and createthicker and less dense membranes. Consequently, the final capsules are more porousand have higher cut-offs (FIG . 7).

CONCLUSIONS

A new generation of microcapsules can be prepared by utilizing a polyelectrolytecomplexation reaction between two oppositely charged polysaccharides, one ofwhich is oligomeric.20 The resulting microcapsules have good mechanical proper-ties and, more significantly in relation to the existing literature, can be applied up toa pH of 7.5. The latter is a necessity of other competing technologies, with bead for-

mation accomplished with the addition of simple electrolyte, normally a divalent

44ANNALS NEW YORK ACADEMY OF SCIENCES

FIGURE 7. Diffusion of dextrans through an alginate/chitosan capsule membrane—different alginate concentrations (chitosan 2.7 kD, reaction time 30 min). The ingress wasmeasured after a contact time of 32 min.

salt. The novel technology forms a membrane directly between two oppositelycharged polyelectrolytes in solution in the absence of simple electrolyte. The newcapsule is unique relative to most polyelectrolyte complex systems in that it involvesa single step process to generate the membrane and microcapsule, avoiding the for-mation of a bead as a precursor. The molar mass of the “outer ” polymer has beenoptimized so as to permit the formation of mechanically stable capsules. Specifical-ly, chitosan oligomers with molar masses between 2 and 20 kD are favored. Theseare envisioned to have applications in the bioencapsulation field in general, pertain-ing specifically to the pharmaceutical, food and cosmetic industries, as well as inbiomedical transplants.

REFERENCES

1. P ARTHASARATHY , R.V. & C.R. MARTIN . 1994. Synthesis of polymeric microcapsulearrays and their use for enzyme immobilization. Nature 369: 298–301. 2. S UN , A.M., Z. CAI , Z. SHI , F. MA & G.M. O’S HEA . 1987. Microencapsulated hepato-cytes: an in vitro and in vivo study. Biomater. Artif. Cells Art. Org. 15: 1483–1496. 3. P EROLS , C., B. PIFFAUT , J. SCHER , J.P. RAMET & D. PONCELET . 1997. The potential ofenzyme entrapment in konjac cold-melting gel beads. Enzyme Microbial Technol.20(1): 57–60. 4. C HUNG , Y.C., C.P. HUANG & C.P. TSENG . 1997. Biotreatment of ammonia from air byan immobilized Arthobacter oxydans CH8 biofilter. Biotechnol. Prog. 13(6): 794–

798.

BARTKOWIAK & HUNKELER: NEW MICROCAPSULES45

5. C HANG , T.M.S. 1995. Artificial cells with emphasis on bioencapsulation in biotechnol-ogy. Biotechnol. Annu. Rev. 1: 267–295. 6. H UNKELER , D. 1997. Polymers for bioartificial organs. Trends Polym. Sci. 5: 286–293. 7. S EFTON , M.V. 1989. Blood, guts and chemical engineering. Can. J. Chem. Eng. 67:705–712. 8. D AUTZENBERG , H., F. LOTH , J. POMMERENING , K.-J. LINOW & D. BARTSCH . 1984.Microcapsules and process for the production therefore, UK Patent Application no.135 954 A.9. S UN , A. M. 1997. Microencapsulation of cells, medical applications. Ann. N.Y. Acad.Sci. 831: 271–279. 10. L IM , F. & A.M. SUN . 1980. Microencapsulated islets as bioartificial endocrine pan-creas. Science 210: 908–910. 11. D E VOS , P. et al. 1997. Effect of alginate composition on the biocompatibility of alg-inate-polylisine microcapsules. Biomaterials 18: 273–278. 12. Z EKORN , T. et al. 1992. Barium-alginate beads for immunoisolated transplantation ofislets of Langerhans. Transplant. Proc. 24: 937–939. 13. B ASTA , G. et al. 1996. J. Ultrastructural examination of pancreatic islet containingalginate/polyaminoacidic coherent microcapsules. Submicrosc. Cytol. Pathol. 28:209–213. 14. S HIGEMASA , Y. & S. MINAMI . 1995. Biotech. Genetic Rev. 13: 383.15. Y AO , K. et al. 1995. Microcapsules and microspheres related to chitosan. J.M.S.-Rev. Macromol. Chem. Phys. C35(1): 155–180. 16. R HA , C. et al. 1984. Biotechnology of Marine Polysaccharides, R.R. Colwell, E.R.Pariser & A.J. Sinskey, eds. Washington: Hempshire Publishing Corp. 283.17. R HA , C. 1985. Process for encapsulation and encapsulated active material system.European Patent Application no.0 152 898.18. R HA , C. 1988. Encapsulated active material system. US Patent 4,749,620.19. D ALY , M.M., R. KEOWN & D.W. KNORR . 1989. Chitosan alginate capsules. USPatent no. 4,808,707.20. B ARTKOWIAK , A. & D. HUNKELER . 1998. UK Patent Application no. GB-A-9814619.4.21. M ULLAGALIEV , I.R. et al. 1995. Degradation of chitosan in the presence of hydrogenperoxide. Poklady Akademii Nauk. 345(2): 199–204. 22. B ARTKOWIAK , A., et al. 1998. Abstract Book of Second International Symposium onPolyelectrolytes, 14. Inuyama, Japan. 31 May–3 June.23. 24. D AUTZENBERG , H. et al. 1996. Immobilisation of biological matter by polyelectrolytecomplex formation. Ber. Bunsenges. Phys. Chem. 100: 1045–1053. 25. M C K NIGHT , C.A. et al. 1988. Synthesis of chitosan-alginate microcaapsule mem-brane. J. Bioact. Comp. Polym. 3: 334–354. 26. B ARTKOWIAK , A. & D. HUNKELER . Alginate-ologoohitoson microcapsules: a mecha-nistic study relating membrane and capsule properties to reaction conditions. Inpreparation.

范文四：101渗透压计算

渗透压:渗透压与溶液中可一元解离的离子浓度有关。如:

+0.1mol/LNaOH溶液可一元解离为0.1mol/L Na和0.1mol/L

-OH。他的渗透压就是0.2 Osm/L=2mOsm/L。

下面我将外文文献中膜提取液与本实验膜提取液以及戴天

明论文中血影蛋白提取液的渗透压进行比较如下:

1972年 Separation and Some Properties of the Major Proteins

of the Human Erythrocyte Membrane

0.155M-NaH2PO4 (iso-osmotic phosphate buffer,pH7.4) The cells were lysed

into 37 litres of a stirred solution of iso osmotic phosphate buffer, pH7.4, diluted with

19.5vol. of deionized water (diluted phosphate buffer, pH7.4) maintained near 0?C

with a cooling coil connected to a circulating refrigeration bath and a solution of

0.3ml of di-isopropyl phosphorofluoridate in 3ml of propanol was immediately added

slowly to the lysate.

等渗缓冲液:0.155M-NaH2PO4，渗透压为0.155 M×2 =0.155mol/L×2=310

+-mOsm/L(注:1 M NaHPO4可一元解离为1 M Na和M HPO，1mol/L NaHPO42242

的渗透压为2 Osm/L=2000 mOsm/L。等渗液的渗透压在280-320 mOsm/L范围内)

低渗缓冲液:将等渗缓冲液用19.5倍体积的去离子水稀释而成。也就是稀释了

20.5倍，渗透压上除以20.5即可。

渗透压为310 mOsm/L?20.5=15 mOsm/L.

低渗液加入少量氟磷酸异丙酯<胆碱酯酶抑制药>和丙醇

本实验中等渗液

rPBS，PH=7.4(KCL137mM,NaCL2.7mM,Na2HPO4 8.1mM,KH2PO4 1.5 mM) 渗透压:137 mM×2+ 2.7 mM ×2+8.1mM×3+ 1.5 mM×2=306.7 mOsm/L

PBS，PH=7.4 (NaCL137mM,KCL2.7mM,Na2HPO4 8.1mM,KH2PO4 1.5 mM，)渗透压同上计算为306.7 mOsm/L

rPBS，PH=5.6 (KCL137mM,NaCL2.7mM,Na2HPO4 0.5mM,KH2PO4 9.5mM) 渗透压为137 mM×2+ 2.7 mM ×2+0.5mM×3+ 9.5 mM×2=299.9 mOsm/L

PBS，PH=5.6 (NaCL137mM,KCL2.7mM,Na2HPO4 0.5mM,KH2PO4 9.5mM，)配

制1L:渗透压同上计算为299.9 mOsm/L

低渗液由等渗液稀释30倍而成，

PH=7.4的渗透压为306.7 mOsm/L /15=20.4 mOsm/L

PH=5.6的渗透压为299.9mOsm/L /15=20 mOsm/L

戴天明论文中

低渗液为0.1mmol/L Na2HPO4,12H2O,加入0.1mmol/L EDTA和0.1mmol/L PMSF。

渗透压为0.1mmol/L×3=0.3 mOsm/L。

文献中低渗透压为15 mOsm/L;

我的20 mOsm/L，曾经查到一篇文献提到PH=5.8-5.9，20 mOsm/L的磷酸缓冲液提取到的膜上最大程度的结合血红蛋白;

戴天明的0.3mOsm/L。

推断:戴天明采用的是低离子强度的低渗溶液，所以能提取出Hb和Sp,而你采用的是提取gohst，所以用的提取液虽然也是低渗，但由于要获得完整的膜骨架，所以不能采用离子强度太低的溶液，否则会将Sp组成的网络会破坏，因为Sp网络除了在与带3、血型糖蛋白等跨膜蛋白以及与带4.1和肌动蛋白结合部位既存在静电作用和疏水作用，在Sp网络的其它部分主要以疏水作用维系，所以采用低离子的低渗溶液不仅能破细胞，而且能将Sp抽提出来同时不涉及对膜蛋白的影响，或者说提取液的经离心后的可溶相中只是Hb和Sp

范文五：渗透压计算

渗透压：渗透压与溶液中可一元解离的离子浓度有关。如：0.1mol/LNaOH溶液可一元解离为0.1mol/L Na+和0.1mol/L OH-。他的渗透压就是0.2 Osm/L=2mOsm/L。

下面我将外文文献中膜提取液与本实验膜提取液以及戴天明论文中血影蛋白提取液的渗透压进行比较如下：

1972年 Separation and Some Properties of the Major Proteins of the Human Erythrocyte Membrane

0.155M-NaH2PO4 (iso-osmotic phosphate buffer,pH7.4) The cells were lysed into 37 litres of a stirred solution of iso osmotic phosphate buffer, pH7.4, diluted with 19.5vol. of deionized water (diluted phosphate buffer, pH7.4) maintained near 0°C with a cooling coil connected to a circulating refrigeration bath and a solution of 0.3ml of di-isopropyl phosphorofluoridate in 3ml of propanol was immediately added slowly to the lysate.

等渗缓冲液：0.155M-NaH2PO4，渗透压为0.155 M×2 =0.155mol/L×2=310 mOsm/L（注：1 M NaH2PO4可一元解离为1 M Na+和M H2PO4-，1mol/L NaH2PO4的渗透压为2 Osm/L=2000 mOsm/L。等渗液的渗透压在280-320 mOsm/L范围内） 低渗缓冲液：将等渗缓冲液用19.5倍体积的去离子水稀释而成。也就是稀释了20.5倍，渗透压上除以20.5即可。

渗透压为310 mOsm/L÷20.5=15 mOsm/L.

低渗液加入少量氟磷酸异丙酯和丙醇

本实验中等渗液

rPBS，PH=7.4(KCL137mM,NaCL2.7mM,Na2HPO4 8.1mM,KH2PO4 1.5

mM) 渗透压：137 mM×2+ 2.7 mM ×2+8.1mM×3+ 1.5 mM×2=306.7 mOsm/L PBS，PH=7.4 (NaCL137mM,KCL2.7mM,Na2HPO4 8.1mM,KH2PO4 1.5 mM，)渗透压同上计算为306.7 mOsm/L

rPBS，PH=5.6 (KCL137mM,NaCL2.7mM,Na2HPO4 0.5mM,KH2PO4 9.5mM) 渗透压为137 mM×2+ 2.7 mM ×2+0.5mM×3+ 9.5 mM×2=299.9 mOsm/L PBS，PH=5.6 (NaCL137mM,KCL2.7mM,Na2HPO4 0.5mM,KH2PO4 9.5mM，)配制1L：渗透压同上计算为299.9 mOsm/L

低渗液由等渗液稀释30倍而成，

PH=7.4的渗透压为306.7 mOsm/L /15=20.4 mOsm/L

PH=5.6的渗透压为299.9mOsm/L /15=20 mOsm/L

戴天明论文中

低渗液为0.1mmol/L Na2HPO4?12H2O,加入0.1mmol/L EDTA和0.1mmol/L PMSF。

渗透压为0.1mmol/L×3=0.3 mOsm/L。

文献中低渗透压为15 mOsm/L；

我的20 mOsm/L，曾经查到一篇文献提到PH=5.8-5.9，20 mOsm/L的磷酸缓冲液提取到的膜上最大程度的结合血红蛋白；

戴天明的0.3mOsm/L。

推断：戴天明采用的是低离子强度的低渗溶液，所以能提取出Hb和Sp,而你采用的是提取gohst，所以用的提取液虽然也是低渗，但由于要获得完整的膜骨架，所以不能采用离子强度太低的溶液，否则会将Sp组成的网络会破坏，因为Sp网络除了在与带3、血型糖蛋白等跨膜蛋白以及与带4.1和肌动蛋白结合部位既存在静电作用和疏水作用，在Sp网络的其它部分主要以疏水作用维系，所以采用低离子的低渗溶液不仅能破细胞，而且能将Sp抽提出来同时不涉及对膜蛋白的影响，或者说提取液的经离心后的可溶相中只是Hb和Sp

转载请注明出处范文大全网 » 渗透压计算