Research Article Separation and Analysis of Boron Isotope ...downloads.hindawi.com/journals/ijac/2015/364242.pdfResearch Article Separation and Analysis of Boron Isotope in High Plant

Research ArticleSeparation and Analysis of Boron Isotope in High Plant byThermal Ionization Mass Spectrometry

Qingcai Xu1 Yuliang Dong1 Huayu Zhu1 and Aide Sun12

1Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental ProtectionCollege of Chemistry and Chemical Engineering Linyi University Linyi 276005 China2State Key Laboratory of Isotope Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of SciencesGuangzhou 510640 China

Correspondence should be addressed to Aide Sun adsun1977gmailcom

Received 5 October 2015 Revised 24 November 2015 Accepted 8 December 2015

Academic Editor David M Lubman

Copyright copy 2015 Qingcai Xu et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Knowledge of boron and its isotope in plants is useful to better understand the transposition and translocation of boron withinplant the geochemical behavior in the interface between soil and plant and the biogeochemical cycle of boron It is critical todevelop a useful method to separate boron from the plant for the geochemical application of boron and its isotope A method wasdeveloped for the extraction of boron in plant sample whose isotope was determined by thermal ionizationmass spectrometryTheresults indicated that this method of dry ashing coupled with two-step ion-exchange chromatography is powerful for the separationof boron in plant sample with large amounts of organic matters completely The ratios of boron isotope composition in those planttissue samples ranged from minus1945permilto +2813permil(total range 4758permil)with a mean value of 261plusmn1176permilSDThe stem and rootisotopic compositions were lower than those in flower and leaf The molecular mechanism of boron isotope may be responsiblefor the observed variation of boron isotopic composition and are considered as a useful tool for the better understanding of boroncycling process in the environment and for the signature of living systems

1 Introduction

Boron (B) is a critical micronutrient in the growth of plantwhich was undoubtedly considered as a part of the structurein the cell wall [1ndash3] More increasing evidence was presentfor a possible role of B in metabolism processes such asthe maintenance of plasma membrane function and severalmetabolic pathways Park and Schlesinger [4] reported thatmost B is fixed into cell wall and is not recycled internallyonce used by plant but some B would be emitted to atmo-sphere in plant aerosol or during the biomass burningWhenplant died the majority is returned to soil The global uptakeof B by plant from soils can be calculated as 45 Tg Byr [4]All of these indicated that the cycling of B and the equilibriumof B isotope in the process between plant and soil would bechanged

In nature B has two stable isotopes 10B and 11B BecauseB shows a large variation in the stable isotopic composition(sim90permil) [5ndash8] B and its isotope have been used to investigate

a wide range of geochemical cosmochemical and geophysi-cal problems Recent concerns about the use of B isotope inbiological systems have been taken into consideration for itsimportant role in embryonic development and organogenesisin plant growth [1 3] and its isotopic fractionation in thecycling of B in the uptake by plant from soil and processingwithin plant by a series of chemical or biochemical reactions

The presence of lots of organic matters in plant can influ-ence the emission of Cs

2BO2

+ ion current in the chamberof TIMS [9 10] In plant the appropriate pretreatment ofsample should effectively remove organic contaminants andmeanwhile keep B isotopic composition stable The methodusing Amberliter IRA 743 resin coupled with cation andanion ion-exchangemixing resin developed by Xiao et al [11]andWang et al [12] was applied as a proxy for the separationof B especially in thewater samplesThe techniques ofmicro-sublimation [13ndash15] and digestion with H

2O2were fit for the

samples with few organicmattersThewet chemical digestionwith HNO

3H2O2in common was used to digest plant

Hindawi Publishing CorporationInternational Journal of Analytical ChemistryVolume 2015 Article ID 364242 6 pageshttpdxdoiorg1011552015364242

2 International Journal of Analytical Chemistry

Table 1 Sampling sites and plant species

Species Sampling location Altitude (m) Longtitude Latitude Habit type Soil typeW florida Linyi Shandong 71 118∘171015840132110158401015840E 35∘61015840212410158401015840N Sand Shantung soilE angustifofia Pingyi Shandong 242 117∘40235210158401015840E 35∘151015840568810158401015840N Sand Cinnamon soilC songaricum Jilantai Inner Mongolia 1060 105∘371015840138310158401015840E 39∘341015840426110158401015840N Sand Sandy soilS mussotii Yushu Qinghai 3585 97∘531015840232810158401015840E 33∘201015840121210158401015840N Shrub grassland Alpine steppe soilH elliptica Banma Qinghai 3514 100∘47101584034810158401015840E 32∘461015840271210158401015840N Bottomland meadow Meadow soil

sample however this method would produce the isobaricCs2CNO+ ion of 119898119911 308 and 309 which affected the deter-

mination of B isotope Wei et al [16] developed a methodusing HF H

2O2 and mannitol mixed solution to separate

B from the silicate rock sample successfully and B isotoperatio was determined by multicollector inductively coupledplasma mass spectrometry (MC-ICP-MS) These techniquesmentioned above were not suitable to eliminate large numberof organicmatters in plant sampleWieser et al [17] and Serraet al [18] attempted B isotopic composition for biogeochem-ical plant-soil interaction and provenance on the coffee beanHowever methods for determining B isotopic compositionin different plant tissues are scarce [19]

In this study a series of dry ashing experiments coupledwith ion-exchange resin chromatography were performed toseparate B in plant tissue sample The B isotopic compositionin plant tissue was determined by positive TIMS based onCs2BO2

+ ion The recoveries of B separation in dry ashingion-exchange chromatography and the whole procedurewere examined And the characteristics and fractionationin the B isotope composition of plant tissue samples wereinvestigated and discussed

2 Material and Methods

21 Plant Sample and Site To examine the fractionation ofB isotopes in different plant species and within plant tissuesplant samples investigated in this study include varioustissues of Swertia mussotii Franch and Halenia elliptica DDon collected in the Qinghai-Tibet Plateau area Weigelaflorida cv Red Prince and Echinacea angustifolia in Shandongarea and Cynomorium songaricum Ruper in Inner Mongoliaarea China The samples of S mussotii and H elliptica werecollected in September and October (the flowering and fruit-ing period) 2012 in Yushu and Banma counties of QinghaiChina respectively The root holoparasite C songaricumknown in Chinese herbal medicine as ldquosuoyangrdquo is a classicMongolian pharmaceutical plant and usually parasitizes theroots of Nitraria spp [20] E angustifolia andW florida werecollected in June 2012The collected samples include the rootstem leaf and flower tissues of W florida S mussotii andH elliptica stem leaf and flower tissues of E angustifoliaand stem and flower ofC songaricumThe information aboutsample site plant species and soil conditions in the regionsis summarized in Table 1

22 Instruments and Reagents Hydrochloric acid (Guaran-teed Reagent) was redistilled in a sealed vessel to removethe exogenous B The cesium carbonate (spectroscopic pure)

was of 99994 purity High-purity graphite was added to amixture of ethanol solution (80) to obtain the final solutioncorresponding to 13mgg graphite The isotopic referencestandard used in this study was NIST SRM 951 boric acid(Gaithersburg MD USA) A solution of mannitol of 182(wv) andCs

2CO3solution containing 123mgmLofCs+was

also prepared Sodium carbonate ammonia hydroxide andsodium chloride were of the analytical grade reagent Boraxand boric acid were of Guaranteed grade Reagent

The resins B specific resin Amberlite IRA 743 strongcation exchange resin Dowex 50W X8 and weakly anionexchange resin Amberlite IRA 67 were purchased fromSigma-Aldrich Co LLC China

High purity water with a B blank less than 0008 120583g wasredistilled by subboiling distillation and passed through aresin column filled with B specific resin (Amberlite IRA 743)which was used to prepare the standard solution andworkingsolution

An inductively coupled plasma optical emission spec-trometer (ICP-OES VistaMPX Varian USA) with a 40MHzradio frequency generator and a charge coupled devicedetector (Vista Chip) was used to detect B

23 Separation of B Dry ashing was also used to decomposeplant sample to eliminate the organic impurities [19] Tradi-tionally plant sample was decomposed using wet chemicaldigestion method of HNO

3H2O2 which can lead to the

formation of the isobaric interference Cs2CNO+ ions of 308

(133Cs2

10BO2

+) and 309 (133Cs2

11BO2

+) in the ionizationchamber in TIMS About 03ndash05 g of dried plant samplewas weighted and placed into a quartz crucible The crucibletogether with plant sample was placed in a closedmicrowave-assist Muffle burner To avoid the bubbling in sample fromrapid heating at first the temperature was raised to 200∘C for1 h for the carbonization of organic matterThen the temper-ature was raised to 550∘C for 4 h until the ash was whitishto black After cooling down 1mL of 05molL HCl solutionwas used to dissolve the ash and the solution was transferredto a polypropylene tube

The B specific resin was used to selectively extract Band to remove the remaining impurities meanwhile The pHin the sample solution was adjusted to 8-9 using 01molLNH3sdotH2O solution and then transferred to the conditioned B

specific resin at a flow rate of 25mLmin After rinsing withultrapure water 10mL of 01molL HCl at 75∘C was used toelute B in the resin then the collected eluates were evapo-rated under a clear air flow at 60∘C until 05mL solution wasleft

International Journal of Analytical Chemistry 3

Table 2 Workflow of the separation of B in plant sample

Workflow Procedure ValidationDecomposition of plant sample Dry ashing Recovery test with Ref Std

B separation(Two-step ion-exchange resin chromatography)

Amberlite IRA 743 resin Recovery test with Ref Std

Mixed ion-exchange resin Isotope fractionation testwith isotopic Ref Std

Determination of B isotope Cs2BO2

+-graphitetechnique for TIMS

Isotope fractionation testwith isotopic Ref Std

Ref Std Reference Standard

Finally the 05mL concentrated solution was transferredto a mixing ion exchange resin column which consists ofa strong cation exchange resin (200ndash400mesh) and a weakanion exchange resin (100ndash120mesh) FifteenmLof ultrapurewater was used to rinse the mixing resin All collected eluateswere transferred to a 15mLTeflon beaker Following the addi-tion of Cs

2CO3solution and mannitol solution evaporation

of the solution continued until about 02mL solution was leftThe solution was transferred to a 05mL centrifuge tube andcontinued evaporating to the approximate concentration of1mgBmL The solution was stored at 4∘C for mass spectro-metric analysis

An outline of the general workflow of B separation inplant sample mentioned above is expressed in Table 2

24 Isotopic Measurement of B The measurement of the Bisotopic ratio was performed using a triton TIMS (ThermoFisher Scientific Inc USA) which was equipped with aspecial double cup system allowing static multicollectionof Cs2

11BO2

+Cs2

10BO2

+ (309308) ions [21 22] Tantalumfilament was degassed at a current of 3 A for 1 h and thencoated with a 25 120583L of graphite slurry solution When theslurry solution was almost dried 1 120583L sample solution wasloaded on top of the graphite and evaporated to dryness Thedetermination of B isotope followed the method reported byXiao et al [22] The 11B10B ratio was calculated as 119877

309308minus

000078 [23 24]The B isotopic composition of the sample is expressed as120575

11B (permil) relative to that of the NIST SRM 951 standard

120575

11B (permil) = [

[

(

11B10B)Sam(

11B10B)Stdminus 1

]

]

times 1000 (1)

Here (11B10B)Sam and (11B10B)Std were the B isotopicratio of sample and NIST SRM 951 H

3BO3 respectively The

measured average 11B10B ratio of NIST SRM 951 H3BO3was

40564 plusmn 00098 (2120590 = 003 119899 = 5)

3 Results and Discussion

31 Recovery of B in the Dry Ashing Most attention has beengiven to the B loss and subsequent isotope fractionation indry ashing and two-step ion-exchange chromatography inbiological samples [19] The B concentration in plant samplewas determined using ICP-OES Wang et al [12] and Xiao etal [11] have reported the effects of pH acidity and salinity

and temperature of HCl solution on the recoveries of B usingAmberlite IRA 743 resin combine with mixing ion-exchangeresin The results indicated that the recovery of B in the two-step ion-exchange chromatography reached to 100 whichmeans there is no B loss in the process So in the followingexperiments the recoveries of B in dry ashing and in wholeprocedure were investigated To examine the B recovery indry ashing borax was used as the reference standard toevaluate the loss of B and the isotopic fractionation in theprocess In the five replicates the mean recovery of 1002was obtained which means that there was no loss of B exceptthe crystal water lost However when H

3BO3was used for

the recovery test in dry ashing there was no B remaining inthe tube which indicated that all B in the format of H

3BO3

would evaporate to air This suggests that when drying ash attemperatures less than 550∘C B in the form of borate will notlose in the sample which indicated the conservative behaviorof B Concurrently low oxygen supply appears to inhibit thevariation of B formation in dry ashing

32 Recovery of B in Whole Procedure The two-step ionexchange chromatography method used for B extractionfrom environmental sample is based on the modificationreported byWang et al [12] and Xiao et al [11]The introduc-tion of the B blank in dry ashing and the chromatographymaychange the recovery and isotopic composition of B Referencestandard borax was used to pass through the procedure toquantify B recovery and to explore the fractionation of Bisotope The total B blank demonstrated here was 0008 120583g Bwhich indicates that the variation of B isotopic compositionin the procedure should be within the external precision ofthe isotopic measurement and therefore ignored The resultsshowed that the recovery of B in the whole procedure rangedfrom 956 to 1102 suggesting B was not lost in the processThe comparison of the B isotopic composition in borax before(12057511B = 508permil 119899 = 5) and after the procedure (12057511B =510permil 119899 = 5) with an error deviation of 035permil suggests Bisotopic composition was not fractionated in the procedureThe recovery yields of B in the complete procedure as well asfor two-step ion-exchange resin chromatographic separationof born in the matrix are shown in Figure 1

33 Amount Variation of B in Tissue The dried amount ofB in plant tissue samples ranged from 287 to 406 120583gg Theresults listed in Figure 2 showed that the dried amount ofB was lowest in the stem and highest in flower In generalthe mean dried amounts of B in leaf (2639 120583gg) and flower


Step 1 Step 2 Total stepsSeparation steps

Dry

ashi

ng

Ion-

exch

ange

ch

rom

atog

raph

y

Who

le p

roce

dure

50

60

70

80

90

100

110

Boro

n re

cove

ry (

)

Figure 1 Recovery yields of B for the individual step and the entireprocedure

S mussotii H ellipticaW florida E angustifoliaC songaricum

Root Stem Leaf FlowerTissues of plant

0

10

20

30

40

50

Am

ount

of b

oron

(120583g

g)

Figure 2 Amounts of B in different plant tissue

(2685 120583gg) were larger than those in root (1571120583gg) andstem (1289 120583gg) In calculating the average of B in stemand flower the results of C songaricum were not taken intoconsideration for the different behavior of B in dried amountsof stem and flower The dried amounts of B in these planttissue samples were similar to those in other plants (10ndash100 120583gg) based on the dry weight reported by Power andWoods [25] In vascular plants B moves from the roots withtranspiration accumulating in the growing points of leavesand stems [1 26] Inmost plant species the B requirement forreproductive growth is higher than that for vegetative growth[27] Huang et al [28] demonstrated that B was transportedfrom leaves into actively growing reproductive organs inwhite lupin (Lupinus albus) These findings suggest that dur-ing plant growth especially in the flowering stage and fruitingperiod a large amount of B is needed to promote growth anddevelopment of plant reproductive tissues which leads to theaccumulation of B in leaves and flowers

34 Fractionation Variation of B Isotopic Composition The120575

11B values in the tissue of these plant samples are shownin Figure 3 The 12057511B (permil) values range from minus1945permilto +2813permil (total range 4758permil) with a mean value of

0

10

20

30



minus20

minus10

minus30

12057511

B (permil

)

Figure 3 Variation of 12057511B in the plant tissues

261 plusmn 1176permil SD When C songaricum was taken intoconsideration for calculation the 12057511B values range fromminus1945permil to 1209permil (range scope 3154permil) with a mean of04plusmn1010permilSDThese results were similar to those reportedby Serra et al [18] with the 12057511B values from minus1160permil to1720permil (mean value 423 plusmn 757permilSD) Except for the stemand flower tissue of C songaricum (Figure 3) the maximummean 12057511B values occurred in the leaf (+758permil) and flowertissue (+790permil) with the minimum 12057511B occurring in stem(minus1211permil) and then in root (minus274permil)

In Figures 2 and 3 the variation of 12057511B is similar to thatof dried amount of B which may be relative to the uptakeand transportation of B within plant In plant growth theuptake of B by root is in the form of B(OH)

3or B(OH)

4

minus [29]B(OH)

3can be taken up by plants through passive diffusion

or an energy dependent high-affinity transport system [30]Borate can form the most stable diesters with cis-diols ona furanoid ring [1 27] The movement of B depends on thesugar or polyol transport molecules [1]

The heavier isotope of B is favored in B(OH)3and

B(OH)4

minus is depleted in 11B thus the variation of 12057511B in rootis lower and closely associated with that in the soil [31] B canbe also transported to reproductive and vegetative tissues [3032] although this capacity varies among species [33 34] AfterB is transported from the root to the stem the 12057511B valuein the root is greater than that in stem as different velocitiesinfluence B mobility by transportation or ion exchangeDuring plant growth a large number of sugar alcohols suchas sorbitol mannitol and fructose which are utilized bythe combination of hydroxyls of B(OH)

3 are required in

the leaves and flowers [35 36] Thus much 11B will prefer-entially go into the leaves and flowers along with B(OH)

3

resulting in higher 12057511B values in the leaf and in flower

35Δ12057511B Values in Higher Plants The fractionation betweentwo components 119894 and 119895 was determined as follows [37]

Δ120575

11B119894minus119895= (120575

11B)119894minus (120575

11B)119895 (2)


0

2

4

6

Root-stem Root-leaf Root-flower

W floridaS mussotii

H elliptica

minus2

minus4

Δ12057511

B (permil

)

Figure 4 B isotope fractionation in tissues (stem leaf and flower)versus root

The variations of Δ12057511B in the plant tissue samples Wflorida Smussotii andH elliptica are illuminated in Figure 4B isotopic composition is significantly fractionated in theplant species and in different tissues of the same plantΔ120575

11Broot-stem Δ12057511Broot-leaf and Δ120575

11Broot-flower inH ellipticawere of 346permil 219permil and 205permil in W florida were of287permil minus083permil and 109permil and in S mussotii were ofminus146permil minus225permil and 01permil

The maximum of Δ12057511B (gt+0permil) was found in the root-stem root-leaf and root-flower of H elliptica which meansthat relative to that inW florida and S mussotiimore 11Bwasused byH elliptica from the region where it growsThemini-mum of those values (ltminus0permil) observed in S mussotii whichindicates that more 10B was accumulated in the tissues of Smussotiimay be caused by the differentmanner of uptake andtransference or by the biophysiological effect of B on plantsThis presence would be another important channel for thevariation of B isotope composition in the global cycle of B byfurther uptake and translocation of B in the tissues of plants

4 Conclusions

A proposed method using dry ashing combined with two-step chromatography was developed for the separation ofB in plant sample which enables applications of B isotopesin biogeochemistry behavior of plant and soil and plantmetabolismWithin the plant the heavier isotope is enrichedin leaf and flower B isotope is fractionated by the mechanismof diffusion transportation or a biological effect betweentissues Moreover knowledge of cycling and fractionationmechanismof B isotope in the uptake of plants will contributeto better understanding of the global biogeochemical cycle ofB

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This work was supported by the Program for Natural ScienceFoundation of China (Grant nos 41403005 and 41201228)the Program for Natural Science Foundation of ShandongProvince China (Grant no ZR2014DL007) and the Project ofShandongProvinceHigher Educational Science andTechnol-ogy Program (Grant no J15LC11)

References

[1] D G Blevins and K M Lukaszewski ldquoBoron in plant structureand functionrdquo Annual Review of Plant Physiology and PlantMolecular Biology vol 49 pp 481ndash500 1998

[2] M A OrsquoNeill T Ishii P Albersheim and A G DarvillldquoRhamnogalacturonan II structure and function of a boratecross-linked cell wall pectic polysacchariderdquo Annual Review ofPlant Biology vol 55 pp 109ndash139 2004

[3] M M Shaaban ldquoRole of boron in plant nutrition and humanhealthrdquo American Journal of Plant Physiology vol 5 no 5 pp224ndash240 2010

[4] H Park andW H Schlesinger ldquoGlobal biogeochemical cycle ofboronrdquo Global Biogeochemical Cycles vol 16 no 4 pp 1072ndash1083 2002

[5] J K Aggarwal and M R Palmer ldquoBoron isotope analysis AreviewrdquoThe Analyst vol 120 no 5 pp 1301ndash1307 1995

[6] S Barth ldquoBoron isotope variations in nature a synthesisrdquoGeologische Rundschau vol 82 no 4 pp 640ndash651 1993

[7] R L Bassett ldquoA critical evaluation of the available measure-ments for the stable isotopes of boronrdquo Applied Geochemistryvol 5 no 5-6 pp 541ndash554 1990

[8] M R Palmer and G H Swihart ldquoBoron isotope geochemistryan overviewrdquo Reviews in Mineralogy vol 33 no 1 pp 709ndash7441996

[9] M Y He Y K Xiao Z D Jin et al ldquoQuantification ofboron incorporation into synthetic calcite under controlled pHand temperature conditions using a differential solubility tech-niquerdquo Chemical Geology vol 337-338 pp 67ndash74 2013

[10] M Y He Y K Xiao Z D Jin et al ldquoAccurate and precisedetermination of boron isotopic ratios at low concentrationby positive thermal ionization mass spectrometry using staticmulticollection of Cs

2BO+2ionsrdquo Analytical Chemistry vol 85

no 13 pp 6248ndash6253 2013[11] Y K Xiao B Y LiaoW G Liu Y Xiao and G H Swihart ldquoIon

exchange extraction of boron from aqueous fluids by amber liteIRA 743 resinrdquo Chinese Journal of Chemistry vol 21 no 8 pp1073ndash1079 2003

[12] Q ZWang Y K Xiao Y HWang C G Zhang and H ZWeildquoBoron separation by the two-step ion-exchange for the isotopicmeasurement of boronrdquo Chinese Journal of Chemistry vol 20no 1 pp 45ndash50 2002

[13] M Y He Y K Xiao Y Q Ma Y L Zhang and J XiaoldquoEffective elimination of organic matter interference in boronisotopic analysis by thermal ionization mass spectrometry ofcoralforaminifera micro-sublimation technology combinedwith ion exchangerdquo Rapid Communications in Mass Spectrome-try vol 25 no 6 pp 743ndash749 2011

[14] A D Sun Q C Xu S J Xu X Shangguan H Shen and J SunldquoDetermination of boron using headspace liquid phase micro-sublimation coupled with inductively coupled plasma opticalemission spectrometryrdquo Analytical Letters vol 46 no 16 pp2610ndash2619 2013


[15] B S Wang C F You K F Huang et al ldquoDirect separation ofboron from Na- and Ca-rich matrices by sublimation for stableisotope measurement by MC-ICP-MSrdquo Talanta vol 82 no 4pp 1378ndash1384 2010

[16] G JWei J XWei Y Liu et al ldquoMeasurement on high-precisionboron isotope of silicate materials by a single column purifi-cation method and MC-ICP-MSrdquo Journal of Analytical AtomicSpectrometry vol 28 no 4 pp 606ndash612 2013

[17] M E Wieser S S Iyer H R Krouse and M I CantagalloldquoVariations in the boron isotope composition of Coffea arabicabeansrdquo Applied Geochemistry vol 16 no 3 pp 317ndash322 2001

[18] F Serra C G Guillou F Reniero et al ldquoDetermination ofthe geographical origin of green coffee by principal componentanalysis of carbon nitrogen and boron stable isotope ratiosrdquoRapid Communications in Mass Spectrometry vol 19 no 15 pp2111ndash2115 2005

[19] M Rosner W Pritzkow J Vogl and S Voerkelius ldquoDevel-opment and validation of a method to determine the boronisotopic composition of crop plantsrdquo Analytical Chemistry vol83 no 7 pp 2562ndash2568 2011

[20] Y C Yang Tibetan Medicines Qinghai People Press XiningChina 1991

[21] A Deyhle ldquoImprovements of boron isotope analysis by positivethermal ionization mass spectrometry using static multicollec-tion of Cs

2BO+2ionsrdquo International Journal of Mass Spectrome-

try vol 206 no 1-2 pp 79ndash89 2001[22] Y K Xiao E S Beary and J D Fassett ldquoAn improved method

for the high-precision isotopic measurement of boron bythermal ionization mass spectrometryrdquo International Journal ofMass Spectrometry and Ion Processes vol 85 no 2 pp 203ndash2131988

[23] B Chetelat J Gaillardet R Freydier and P Negrel ldquoBoronisotopes in precipitation experimental constraints and fieldevidence from French Guianardquo Earth and Planetary ScienceLetters vol 235 no 1-2 pp 16ndash30 2005

[24] T Nakano and E Nakamura ldquoStatic multicollection of Cs2BO+2

ions for precise boron isotope analysis with positive thermalionization mass spectrometryrdquo International Journal of MassSpectrometry vol 176 no 1-2 pp 13ndash21 1998

[25] P P Power and W G Woods ldquoThe chemistry of boron and itsspeciation in plantsrdquo Plant and Soil vol 193 no 1 pp 1ndash13 1997

[26] C J Lovatt ldquoEvolution of xylem resulted in a requirement forboron in the apical meristems of vascular plantsrdquo New Phytolo-gist vol 99 no 4 pp 509ndash522 1985

[27] W D Loomis and R W Durst ldquoChemistry and biology ofboronrdquo BioFactors vol 3 no 4 pp 229ndash239 1992

[28] L Huang R W Bell and B Dell ldquoEvidence of phloem borontransport in response to interrupted boron supply inwhite lupin(Lupinus albus L cv Kiev Mutant) at the reproductive stagerdquoJournal of Experimental Botany vol 59 no 3 pp 575ndash583 2008

[29] X Y Jiao Y G Zhu B C Jarvis W P Quick and P ChristieldquoEffects of boron on leaf expansion and intercellular airspaces inmung bean in solution culturerdquo Journal of Plant Nutrition vol28 no 2 pp 351ndash361 2005

[30] B J Shelp E Marentes A M Kitheka and P VivekanandanldquoBoron mobility in plantsrdquo Physiologia Plantarum vol 94 no2 pp 356ndash361 1995

[31] M Tanaka and T Fujiwara ldquoPhysiological roles and trans-port mechanisms of boron perspectives from plantsrdquo PflugersArchivmdashEuropean Journal of Physiology vol 456 no 4 pp 671ndash677 2008

[32] TMatoh andKOchiai ldquoDistribution and partitioning of newlytaken-up boron in sunflowerrdquo Plant and Soil vol 278 no 1-2pp 351ndash360 2005

[33] P H Brown and B J Shelp ldquoBoron mobility in plantsrdquo Plantand Soil vol 193 no 1-2 pp 85ndash101 1997

[34] H E Goldbach ldquoA critical review on current hypothesisconcerning the role of boron in higher plants suggestion forfurther research and methodological requirementsrdquo Journal ofTrace and Microprobe Techniques vol 15 pp 51ndash91 1997

[35] H Hu and P H Brown ldquoPhloem mobility of boron isspecies dependent evidence for phloem mobility in sorbitol-rich speciesrdquo Annals of Botany vol 77 no 5 pp 497ndash505 1996

[36] HHu S G Penn C B Lebrilla and PH Brown ldquoIsolation andcharacterization of soluble boron complexes in higher plantsrdquoPlant Physiology vol 113 no 2 pp 649ndash655 1997

[37] F Moynier S Pichat M L Pons D Fike V Balter and FAlbarede ldquoIsotopic fractionation and transport mechanisms ofZn in plantsrdquo Chemical Geology vol 267 no 3-4 pp 125ndash1302009

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


Table 1 Sampling sites and plant species

Species Sampling location Altitude (m) Longtitude Latitude Habit type Soil typeW florida Linyi Shandong 71 118∘171015840132110158401015840E 35∘61015840212410158401015840N Sand Shantung soilE angustifofia Pingyi Shandong 242 117∘40235210158401015840E 35∘151015840568810158401015840N Sand Cinnamon soilC songaricum Jilantai Inner Mongolia 1060 105∘371015840138310158401015840E 39∘341015840426110158401015840N Sand Sandy soilS mussotii Yushu Qinghai 3585 97∘531015840232810158401015840E 33∘201015840121210158401015840N Shrub grassland Alpine steppe soilH elliptica Banma Qinghai 3514 100∘47101584034810158401015840E 32∘461015840271210158401015840N Bottomland meadow Meadow soil

sample however this method would produce the isobaricCs2CNO+ ion of 119898119911 308 and 309 which affected the deter-

mination of B isotope Wei et al [16] developed a methodusing HF H

2O2 and mannitol mixed solution to separate

B from the silicate rock sample successfully and B isotoperatio was determined by multicollector inductively coupledplasma mass spectrometry (MC-ICP-MS) These techniquesmentioned above were not suitable to eliminate large numberof organicmatters in plant sampleWieser et al [17] and Serraet al [18] attempted B isotopic composition for biogeochem-ical plant-soil interaction and provenance on the coffee beanHowever methods for determining B isotopic compositionin different plant tissues are scarce [19]

In this study a series of dry ashing experiments coupledwith ion-exchange resin chromatography were performed toseparate B in plant tissue sample The B isotopic compositionin plant tissue was determined by positive TIMS based onCs2BO2

+ ion The recoveries of B separation in dry ashingion-exchange chromatography and the whole procedurewere examined And the characteristics and fractionationin the B isotope composition of plant tissue samples wereinvestigated and discussed

2 Material and Methods

21 Plant Sample and Site To examine the fractionation ofB isotopes in different plant species and within plant tissuesplant samples investigated in this study include varioustissues of Swertia mussotii Franch and Halenia elliptica DDon collected in the Qinghai-Tibet Plateau area Weigelaflorida cv Red Prince and Echinacea angustifolia in Shandongarea and Cynomorium songaricum Ruper in Inner Mongoliaarea China The samples of S mussotii and H elliptica werecollected in September and October (the flowering and fruit-ing period) 2012 in Yushu and Banma counties of QinghaiChina respectively The root holoparasite C songaricumknown in Chinese herbal medicine as ldquosuoyangrdquo is a classicMongolian pharmaceutical plant and usually parasitizes theroots of Nitraria spp [20] E angustifolia andW florida werecollected in June 2012The collected samples include the rootstem leaf and flower tissues of W florida S mussotii andH elliptica stem leaf and flower tissues of E angustifoliaand stem and flower ofC songaricumThe information aboutsample site plant species and soil conditions in the regionsis summarized in Table 1

22 Instruments and Reagents Hydrochloric acid (Guaran-teed Reagent) was redistilled in a sealed vessel to removethe exogenous B The cesium carbonate (spectroscopic pure)

was of 99994 purity High-purity graphite was added to amixture of ethanol solution (80) to obtain the final solutioncorresponding to 13mgg graphite The isotopic referencestandard used in this study was NIST SRM 951 boric acid(Gaithersburg MD USA) A solution of mannitol of 182(wv) andCs

2CO3solution containing 123mgmLofCs+was

also prepared Sodium carbonate ammonia hydroxide andsodium chloride were of the analytical grade reagent Boraxand boric acid were of Guaranteed grade Reagent

The resins B specific resin Amberlite IRA 743 strongcation exchange resin Dowex 50W X8 and weakly anionexchange resin Amberlite IRA 67 were purchased fromSigma-Aldrich Co LLC China

High purity water with a B blank less than 0008 120583g wasredistilled by subboiling distillation and passed through aresin column filled with B specific resin (Amberlite IRA 743)which was used to prepare the standard solution andworkingsolution

An inductively coupled plasma optical emission spec-trometer (ICP-OES VistaMPX Varian USA) with a 40MHzradio frequency generator and a charge coupled devicedetector (Vista Chip) was used to detect B

23 Separation of B Dry ashing was also used to decomposeplant sample to eliminate the organic impurities [19] Tradi-tionally plant sample was decomposed using wet chemicaldigestion method of HNO

3H2O2 which can lead to the

formation of the isobaric interference Cs2CNO+ ions of 308

(133Cs2

10BO2

+) and 309 (133Cs2

11BO2

+) in the ionizationchamber in TIMS About 03ndash05 g of dried plant samplewas weighted and placed into a quartz crucible The crucibletogether with plant sample was placed in a closedmicrowave-assist Muffle burner To avoid the bubbling in sample fromrapid heating at first the temperature was raised to 200∘C for1 h for the carbonization of organic matterThen the temper-ature was raised to 550∘C for 4 h until the ash was whitishto black After cooling down 1mL of 05molL HCl solutionwas used to dissolve the ash and the solution was transferredto a polypropylene tube

The B specific resin was used to selectively extract Band to remove the remaining impurities meanwhile The pHin the sample solution was adjusted to 8-9 using 01molLNH3sdotH2O solution and then transferred to the conditioned B

specific resin at a flow rate of 25mLmin After rinsing withultrapure water 10mL of 01molL HCl at 75∘C was used toelute B in the resin then the collected eluates were evapo-rated under a clear air flow at 60∘C until 05mL solution wasleft
















11BO2

+Cs2

10BO2


309308minus



120575

11B (permil) = [

[

(

11B10B)Sam(

11B10B)Stdminus 1

]

]

times 1000 (1)




40564 plusmn 00098 (2120590 = 003 119899 = 5)




3BO3was used for


3BO3






Dry

ashi

ng

Ion-

exch

ange

ch

rom

atog

raph

y

Who

le p

roce

dure

50

60

70

80

90

100

110

Boro

n re

cove

ry (

)




0

10

20

30

40

50

Am

ount

of b

oron

(120583g

g)





0

10

20

30



minus20

minus10

minus30

12057511

B (permil

)




3or B(OH)

4

minus [29]B(OH)




B(OH)4


3 are required in


3



Δ120575

11B119894minus119895= (120575

11B)119894minus (120575

11B)119895 (2)


0

2

4

6


W floridaS mussotii

H elliptica

minus2

minus4

Δ12057511

B (permil

)






4 Conclusions




Acknowledgments


References





















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of
















11BO2

+Cs2

10BO2


309308minus



120575

11B (permil) = [

[

(

11B10B)Sam(

11B10B)Stdminus 1

]

]

times 1000 (1)




40564 plusmn 00098 (2120590 = 003 119899 = 5)




3BO3was used for


3BO3






Dry

ashi

ng

Ion-

exch

ange

ch

rom

atog

raph

y

Who

le p

roce

dure

50

60

70

80

90

100

110

Boro

n re

cove

ry (

)




0

10

20

30

40

50

Am

ount

of b

oron

(120583g

g)





0

10

20

30



minus20

minus10

minus30

12057511

B (permil

)




3or B(OH)

4

minus [29]B(OH)




B(OH)4


3 are required in


3



Δ120575

11B119894minus119895= (120575

11B)119894minus (120575

11B)119895 (2)


0

2

4

6


W floridaS mussotii

H elliptica

minus2

minus4

Δ12057511

B (permil

)






4 Conclusions




Acknowledgments


References





















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



Dry

ashi

ng

Ion-

exch

ange

ch

rom

atog

raph

y

Who

le p

roce

dure

50

60

70

80

90

100

110

Boro

n re

cove

ry (

)




0

10

20

30

40

50

Am

ount

of b

oron

(120583g

g)





0

10

20

30



minus20

minus10

minus30

12057511

B (permil

)




3or B(OH)

4

minus [29]B(OH)




B(OH)4


3 are required in


3



Δ120575

11B119894minus119895= (120575

11B)119894minus (120575

11B)119895 (2)


0

2

4

6


W floridaS mussotii

H elliptica

minus2

minus4

Δ12057511

B (permil

)






4 Conclusions




Acknowledgments


References





















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


0

2

4

6


W floridaS mussotii

H elliptica

minus2

minus4

Δ12057511

B (permil

)






4 Conclusions




Acknowledgments


References





















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of





































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of










Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

Documents

Research Article Separation and Analysis of Boron Isotope ...downloads.hindawi.com/journals/ijac/2015/364242.pdfResearch Article Separation and Analysis of Boron Isotope in High Plant