Effect of Laser Energy Density on Data Quality during LA-ICP-MS Measurement

WANG Hui; WANG Fang-yue; GUAN Bing-ting; SHENG Zhao-qiu

doi:10.15898/j.cnki.11-2131/td.201903010029

Rock and Mineral Analysis > 2019 > 38(6): 609-619. > DOI: 10.15898/j.cnki.11-2131/td.201903010029

WANG Hui, WANG Fang-yue, GUAN Bing-ting, SHENG Zhao-qiu. Effect of Laser Energy Density on Data Quality during LA-ICP-MS Measurement[J]. Rock and Mineral Analysis, 2019, 38(6): 609-619. DOI: 10.15898/j.cnki.11-2131/td.201903010029

Citation:

PDF (2148 KB)

Effect of Laser Energy Density on Data Quality during LA-ICP-MS Measurement

1.
State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
2.
School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China
3.
University of Chinese Academy of Science, Beijing 100049, China
4.
Ore Deposit and Exploration Centre, Hefei University of Technology, Hefei 230009, China
5.
Yunnan Jinchangjiang Mine Industry Co., LTD, Zhaoqing 526300, China
6.
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China

More Information

Received Date: February 28, 2019
Revised Date: May 23, 2019
Accepted Date: July 15, 2019
Published Date: October 31, 2019

Abstract

HIGHLIGHTS
(1) The minimum laser energy density for stable denudating minerals of different Mohs hardness was determined during LA-ICP-MS measurement.

(2) The effects of various laser energy densities on the data quality for standard samples and natural minerals were evaluated.

(3) The greater the laser energy density in the appropriate range, the smaller the average relative error of the data.

ABSTRACT

BACKGROUNDLaser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is a frequent instrument for the analysis of trace element content. When LA-ICP-MS is used to analyze the element content of minerals, the laser energy density will affect the denudation rate of the sample and thus affect the signal intensity during the analysis.
OBJECTIVESTo further clarify the impact of laser energy density changes on the quality of test data and the response of different natural minerals to laser energy density.
METHODSThe element content data of standard samples and nature minerals with different Mohs hardness under different laser energy densities were determined using LA-ICP-MS. Then authors analyzed the relative error (RE) between the test data and the reference values of the standard samples, average of the relative error of elements with RE within the limits of -20%-10% in the same standard sample, and the relative standard deviation of the standard samples and nature minerals test results to evaluate the effect of laser energy density on the test results.
RESULTSThe minimum laser energy density required to stabilize ablated quartz and fluorite was 4-5J/cm², which was lower than the previously reported value (10J/cm²), whereas stable denudation of other minerals such as talc, apatite, and corundum require the minimum energy density of generally 1-2J/cm². Under the different condition of laser energy density, the relative error of most trace elements in standard samples between analytical results and recommended values was less than 20% and the relative standard deviation was less than 10%. The relative standard deviation of most trace element test data was less than 20% for natural minerals with most element contents >1μg/g. Within a certain range, the greater the laser energy density, the smaller the average relative error of the data, and the better the overall quality.
CONCLUSIONSQuartz and fluorite require higher laser energy density for stable ablation than other minerals. Within the appropriate range, laser energy density has little effect on the quality of the individual element data, but it affects the overall quality of the data.
- LA-ICP-MS,
- laser energy density,
- standard samples,
- natural minerals,
- data quality

FullText(HTML)

References (60)

References

Durrant S F.Feasibility of improvement in analytical per-formance in laser-ablation inductively-coupled plasma-mass spectrometry (LA-ICP-MS) by addition of nitrogen to the argon plasma[J].Fresenius Journal of Analytical Chemistry, 1994, 349(10-11):768-771. doi: 10.1007/BF00325655

Kozono S, Haraguchi H.Determination of ultratrace im-purity elements in high purity niobium materials by on-line matrix separation and direct injection/inductively coupled plasma mass spectrometry[J].Talanta, 2007, 72(5):1791-1799. doi: 10.1016/j.talanta.2007.02.021

Zhang W, Hu Z, Liu Y, et al.Improved in situ Sr isotopic analysis by a 257nm femtosecond laser in combination with the addition of nitrogen for geological minerals[J].Chemical Geology, 2018, 479(none):10-21. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=5819ee64271c8a80c3bbba21c4ad40b5

Gray A L.Solid sample introduction by laser ablation for inductively coupled plasma source-mass spectrometry[J].Analyst, 1985, 110(5):551-556. doi: 10.1039/an9851000551

Miliszkiewicz N, Walas S, Tobiasz A.Current approaches to calibration of LA-ICP-MS analysis[J].Journal of Analytical Atomic Spectrometry, 2015, 30(2):327-338. doi: 10.1039/C4JA00325J

袁洪林, 高山, 戴梦宁, 等.流体包裹体中Sr同位素的激光剥蚀多接收等离子体质谱原位微区分析[J].矿物岩石地球化学通报, 2009, 28(4):313-317. doi: 10.3969/j.issn.1007-2802.2009.04.001

Yuan H L, Gao S, Dai M N, et al.In situ strontium isotope analysis of fluid inclusion using LA-MC-ICPMS[J].Bulletin of Mineralogy, Petrology and Geochemistry, 2009, 28(4):313-317. doi: 10.3969/j.issn.1007-2802.2009.04.001

Eggins S M.Laser ablation ICP-MS analysis of geo-logical materials prepared as lithium borate glasses[J].Geostandards Newsletter, 2003, 27(2):147-162. doi: 10.1111/j.1751-908X.2003.tb00642.x

Liu Y S, Hu Z C, Li M, et al.Applications of LA-ICP-MS in the elemental analyses of geological samples[J].Chinese Science Bulletin, 2013, 58(32):3863-3878. doi: 10.1007/s11434-013-5901-4

Garcia de Madinabeitia S, Sanchez Lorda M E, Ibarguchi J I.Simultaneous determination of major to ultratrace elements in geological samples by fusion-dissolution and inductively coupled plasma mass spectrometry techniques[J].Analytica Chimica Acta, 2008, 625(2):117-130. doi: 10.1016/j.aca.2008.07.024

Upadhyay N, Majestic B J, Prapaipong P, et al.Evalua-tion of polyurethane foam, polypropylene, quartz fiber, and cellulose substrates for multi-element analysis of atmospheric particulate matter by ICP-MS[J].Analytical & Bioanalytical Chemistry, 2009, 394(1):255-266. http://med.wanfangdata.com.cn/Paper/Detail/PeriodicalPaper_PM19242682

汪奇, 张文, 王立云, 等.激光剥蚀-电感耦合等离子体质谱测定植物样品中的元素[J].光谱学与光谱分析, 2011, 31(12):3379-3383. doi: 10.3964/j.issn.1000-0593(2011)12-3379-05

Wang Q, Zhang W, Wang L Y, et al.Quantitative determination of elements in plant samples by laser ablation inductively coupled plasma mass spectrometry[J].Spectroscopy and Spectral Analysis, 2011, 31(12):3379-3383. doi: 10.3964/j.issn.1000-0593(2011)12-3379-05

Löhr K, Traub H, Wanka A J, et al.Quantification of metals in single cells by LA-ICP-MS:Comparison of single spot analysis and imaging[J].Journal of Analytical Atomic Spectrometry, 2018, 33(9):1579-1587. doi: 10.1039/C8JA00191J

Ren H D, Wang T, Zhang L, et al.Ages, sources and tectonic settings of the triassic igneous rocks in the easternmost segment of the East Kunlun Orogen, Central China[J].Acta Geologica Sinica (English Edition), 2016, 90(2):641-668. doi: 10.1111/1755-6724.12696

Li W, Liu Y Q, Dong Y P, et al.The geochemical cha-racteristics, geochronology and tectonic significance of the Carboniferous volcanic rocks of the Santanghu area in Northeastern Xinjiang, China[J].Science China (Earth Sciences), 2013, 56(8):1318-1333. doi: 10.1007/s11430-012-4483-3

Xiao X, Zhou T F, Fan Y, et al.LA-ICP-MS in situ trace elements and FE-SEM analysis of pyrite from the Xinqiao Cu-Au-S deposit in Tongling, Anhui and its constraints on the ore genesis[J].Acta Petrologica Sinica, 2016, 32(2):369-376. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=ysxb98201602007

Zhang L Y, Li N, Prelevic D.The research status of olivine trace elements in-situ analysis and perspectives of its application[J].Acta Petrologica Sinica, 2016, 32(6):1877-1890. http://d.old.wanfangdata.com.cn/Periodical/ysxb98201606020

Pettke T, Oberli F, Audetat A, et al.Recent develop-ments in element concentration and isotope ratio analysis of individual fluid inclusions by laser ablation single and multiple collector ICP-MS[J].Ore Geology Reviews, 2012, 44:10-38. doi: 10.1016/j.oregeorev.2011.11.001

Li C Y, Jiang Y H, Zhao Y, et al.Trace element analyses of fluid inclusions using laser ablation ICP-MS[J].Solid Earth Sciences, 2018, 3(1):8-15. doi: 10.1016/j.sesci.2017.12.001

Fusswinkel T, Giehl C, Beermann O, et al.Combined LA-ICP-MS microanalysis of iodine, bromine and chlorine in fluid inclusions[J].Journal of Analytical Atomic Spectrometry, 2018, 33(5):768-783. doi: 10.1039/C7JA00415J

范晨子, 詹秀春, 曾普胜, 等.白云鄂博稀土氟碳酸盐矿物的LA-ICP-MS多元素基体归一定量分析方法研究[J].岩矿测试, 2015, 34(6):609-616. doi: 10.15898/j.cnki.11-2131/td.2015.06.002

Fan C Z, Zhan X C, Zeng P S, et al.Multi-element cont-ent analysis of rare earth fluorocarbonates from Bayan Obo deposit by laser ablation-inductively coupled plasma-mass spectrometry[J].Rock and Mineral Analysis, 2016, 34(6):609-616. doi: 10.15898/j.cnki.11-2131/td.2015.06.002

Drost K, Chew D, Petrus J A, et al.An image mapping approach to U-Pb LA-ICP-MS carbonate dating and applications to direct dating of carbonate sedimentation[J].Geochemistry, Geophysics, Geosystems, 2018, 19(12):4631-4648. doi: 10.1029/2018GC007850

Peng S, Hu Q, Ewing R P, et al.Quantitative 3-D elemental mapping by LA-ICP-MS of a basaltic clast from the Hanford 300 Area, Washington, USA[J].Environmental Science & Technology, 2012, 46(4):2025-2032. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=adc88081136a8ddaab91343cf30bdceb

Norman M D, Pearson N J, Sharma A, et al.Quantitative analysis of trace elements in geological materials by laser ablation ICPMS:Instrumental operating conditions and calibration values of NIST glasses[J].Geostandards Newsletter, 1996, 20(2):247-261. doi: 10.1111/j.1751-908X.1996.tb00186.x

周文喜, 王华建, 付勇, 等.基于LA-ICP-MS多元素成像技术的早寒武世磷结核成因研究[J].岩矿测试, 2017, 36(2):97-106. doi: 10.15898/j.cnki.11-2131/td.2017.02.002

Zhou W X, Wang H J, Fu Y, et al.Study on the formation mechanism of phosphate nodules in the Early Cambrian period using LA-ICP-MS multi-element imaging technology[J].Rock and Mineral Analysis, 2017, 36(2):97-106. doi: 10.15898/j.cnki.11-2131/td.2017.02.002

Chen Y T, Naessens K, Baets R, et al.Ablation of tran-sparent materials using excimer lasers for photonic applications[J].Optical Review, 2005, 12(6):427-441. doi: 10.1007/s10043-005-0427-x

何飞, 程亚.飞秒激光微加工:激光精密加工领域的新前沿[J].中国激光, 2007, 34(5):595-622. doi: 10.3321/j.issn:0258-7025.2007.05.001

He F, Cheng Y.Femtosecond laser micromachining:Frontier in laser precision micromachining[J].Chinese Journal of Laser, 2007, 34(5):595-622. doi: 10.3321/j.issn:0258-7025.2007.05.001

罗彦, 胡圣虹, 刘勇胜, 等.激光剥蚀电感耦合等离子体质谱微区分析新进展[J].分析化学, 2001, 29(11):1345-1352. doi: 10.3321/j.issn:0253-3820.2001.11.026

Luo Y, Hu S H, Liu Y S, et al.Recent trends in laser ablation inductively coupled plasma-mass spectrometric microanalysis[J].Chinese Journal of Analytical Chemistry, 2001, 29(11):1345-1352. doi: 10.3321/j.issn:0253-3820.2001.11.026

Günther D, Heinrich C A.Comparison of the ablation behaviour of 266nm Nd:YAG and 193nm ArF excimer lasers for LA-ICP-MS analysis[J].Journal of Analytical Atomic Spectrometry, 1999, 14(9):1369-1374. doi: 10.1039/A901649J

Günther D, Frischknecht R, Heinrich C A, et al.Capabi-lities of an argon fluoride 193nm excimer laser for laser ablation inductively coupled plasma mass spectometry microanalysis of geological materials[J].Journal of Analytical Atomic Spectrometry, 1997, 12(9):939-944. doi: 10.1039/A701423F

Güillong M, Horn I, Günther D.A comparison of 266nm, 213nm and 193nm produced from a single solid state Nd:YAG laser for laser ablation ICP-MS[J].Journal of Analytical Atomic Spectrometry, 2003, 18(10):1224-1230. doi: 10.1039/B305434A

Gaboardi M, Humayun M.Elemental fractionation during LA-ICP-MS analysis of silicate glasses:Implications for matrix-independent standardization[J].Journal of Analytical Atomic Spectrometry, 2009, 24(9):1188-1197. doi: 10.1039/b900876d

Russo R E, Mao X L, Borisov O V, et al.Influence of wavelength on fractionation in laser ablation ICP-MS[J].Journal of Analytical Atomic Spectrometry, 2000, 15(9):1115-1120. doi: 10.1039/b004243i

柯于球, 张路远, 郑洪涛, 等.硫化物矿物LA-ICP-MS微区分析激光剥蚀行为研究[J].冶金分析, 2010, 30(增刊):417-419. http://d.old.wanfangdata.com.cn/Conference/7364294

Ke Y Q, Zhang L Y, Zheng H T, et al.An investigation on laser ablation behavior of sulfide mineral in LA-ICP-MS microanalysis[J].Metallurgical Analysis, 2010, 30(Supplement):417-419. http://d.old.wanfangdata.com.cn/Conference/7364294

Horn I, Günther D.The influence of ablation carrier gasses Ar, He and Ne on the particle size distribution and transport efficiencies of laser ablation-induced aerosols:Implications for LA-ICP-MS[J].Applied Surface Science, 2003, 207(1-4):144-157. doi: 10.1016/S0169-4332(02)01324-7

Garcia C C, Lindner H, Niemax K.Laser ablation induc-tively coupled plasma mass spectrometry-Current shortcomings, practical suggestions for improving performance, and experiments to guide future development[J].Journal of Analytical Atomic Spectrometry, 2009, 24(1):14-26. doi: 10.1039/B813124B

吴石头, 许春雪, Klaus S, 等.193nm ArF准分子激光系统对LA-ICP-MS分析中不同基体的剥蚀行为和剥蚀速率探究[J].岩矿测试, 2017, 36(5):451-459. doi: 10.15898/j.cnki.11-2131/td.201703290044

Wu S T, Xu C X, Klaus S, et al.Study on ablation behaviors and ablation rates of a 193nm ArF excimer laser system for selected substrates in LA-ICP-MS analysis[J].Rock and Mineral Analysis, 2017, 36(5):451-459. doi: 10.15898/j.cnki.11-2131/td.201703290044

王辉, 汪方跃, 盛兆秋.LA-ICP-MS分析中不同莫氏硬度矿物激光剥蚀行为及剥蚀速率研究[J].岩石矿物学杂志, 2019, 38(1):113-120. doi: 10.3969/j.issn.1000-6524.2019.01.010

Wang H, Wang F Y, Sheng Z Q.The laser ablation behavior and rate of minerals with different Mohs hardnesses in LA-ICP-MS analysis[J].Acta Petrologica et Mineralogica, 2019, 38(1):113-120. doi: 10.3969/j.issn.1000-6524.2019.01.010

吴石头, 王亚平, 许春雪.激光剥蚀电感耦合等离子体质谱元素微区分析标准物质研究进展[J].岩矿测试, 2015, 34(5):503-511. doi: 10.15898/j.cnki.11-2131/td.2015.05.002

Wu S T, Wang Y P, Xu C X.Research progress on reference materials for in situ elemental analysis by laser ablation-inductively coupled plasma-mass spectro-metry[J].Rock and Mineral Analysis, 2015, 34(5):503-511. doi: 10.15898/j.cnki.11-2131/td.2015.05.002

Marcel G, Kathrin H, Eric R, et al.Preliminary charac-terisation of new glass reference materials (GSA-1G, GSC-1G, GSD-1G and GSE-1G) by laser ablation-inductively coupled plasma-mass spectrometry using 193nm, 213nm and 266nm wavelengths[J].Geostandards and Geoanalytical Research, 2005, 29(3):315-331. doi: 10.1111/j.1751-908X.2005.tb00903.x

Regnery J, Stoll B, Jochum K P.High-resolution LA-ICP-MS for accurate determination of low abundances of K, Sc and other trace elements in geological samples[J].Geostandards and Geoanalytical Research, 2010, 34(1):19-38. doi: 10.1111/j.1751-908X.2009.00025.x

Liu Y S, Hu Z C, Gao S, et al.In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard[J].Chemical Geology, 2008, 257(1-2):34-43. doi: 10.1016/j.chemgeo.2008.08.004

Bulska E, Wagner B.Quantitative aspects of inductively coupled plasma mass spectrometry[J].Philosophical Transactions of the Royal Society A:Mathematical, Physical and Engineering Sciences, 2016, 374(2079):20150369. doi: 10.1098/rsta.2015.0369

宁思远, 汪方跃, 薛维栋, 等.长江中下游铜陵地区宝山岩体地球化学研究[J].地球化学, 2017, 46(5):397-412. doi: 10.3969/j.issn.0379-1726.2017.05.001

Ning S Y, Wang F Y, Xue W D, et al.Geochemistry of the Baoshan Pluton in the Tongling region of the Lower Yangtze River Belt[J].Geochemical, 2017, 46(5):397-412. doi: 10.3969/j.issn.0379-1726.2017.05.001

汪方跃, 葛粲, 宁思远, 等.一个新的矿物面扫描分析方法开发和地质学应用[J].岩石学报, 2017, 33(11):3422-3436. http://d.old.wanfangdata.com.cn/Periodical/ysxb98201711006

Wang F Y, Ge C, Ning S Y, et al.A new approach to LA-ICP-MS mapping and application in geology[J].Acta Petrologica Sinica, 2017, 33(11):3422-3436. http://d.old.wanfangdata.com.cn/Periodical/ysxb98201711006

徐鸿志, 靳兰兰, 李爱荣, 等.激光剥蚀等离子体质谱分析中激光剥蚀参数对信号响应的影响[J].岩矿测试, 2005, 24(3):171-175. doi: 10.3969/j.issn.0254-5357.2005.03.003

Xu H Z, Jin L L, Li A R, et al.The effects of laser ablation operating parameters on signal response in LA-ICP-MS microanalysis[J].Rock and Mineral Analysis, 2005, 24(3):171-175. doi: 10.3969/j.issn.0254-5357.2005.03.003

Russo R E, Mao X L, Liu C, et al.Laser assisted plasma spectrochemistry:Laser ablation[J].Journal of Analytical Atomic Spectrometry, 2004, 19(9):1084-1089. doi: 10.1039/b403368j

陈玉红, 王海舟.激光剥蚀-电感耦合等离子体质谱法中元素分馏效应的影响因素及其评价[J].冶金分析, 2008, 28(8):1-6. doi: 10.3969/j.issn.1000-7571.2008.08.001

Chen Y H, Wang H Z.Influence factors and evaluation of elemental fractionation in laser ablation inductively coupled plasma mass spectrometry[J].Metallurgical Analysis, 2008, 28(8):1-6. doi: 10.3969/j.issn.1000-7571.2008.08.001

Nadoll P, Koenig A E.LA-ICP-MS of magnetite:Methods and reference materials[J].Journal of Analytical Atomic Spectrometry, 2011, 26(9):1872-1877. doi: 10.1039/c1ja10105f

Kuhn H R, Günther D.Laser ablation-ICP-MS:Particle size dependent elemental composition studies on filter-collected and online measured aerosols from glass[J].Journal of Analytical Atomic Spectrometry, 2004, 19(9):1158-1164. doi: 10.1039/B404729J

Eggins S M, Shelley J M G.Compositional heterogeneity in NIST SRM610-617 glasses[J].Geostandards Newsletter, 2002, 26(3):269-286. doi: 10.1111/j.1751-908X.2002.tb00634.x

Pearce N J, Perkins W T, Westgate J A, et al.A compilation of new and published major and trace element data for NIST SRM610 and NIST SRM612 glass reference materials[J].Geostandards Newsletter, 1997, 21(1):115-144. doi: 10.1111/j.1751-908X.1997.tb00538.x

Jochum K P, Weis U, Stoll B, et al.Determination of reference values for NIST SRM610-617 glasses following ISO guidelines[J].Geostandards and Geoanalytical Research, 2011, 35(4):397-429. doi: 10.1111/j.1751-908X.2011.00120.x

Rocholl A B, Simon K, Jochum K P, et al.Chemical characterisation of NIST silicate glass certified reference material SRM610 by ICP-MS, TIMS, LIMS, SSMS, INAA, AAS and PIXE[J].Geostandards Newsletter, 1997, 21(1):101-114. doi: 10.1111/j.1751-908X.1997.tb00537.x

Jochum K P, Stoll B, Herwig K, et al.MPI-DING re-ference glasses for in situ microanalysis:New reference values for element concentrations and isotope ratios[J].Geochemistry, Geophysics, Geosystems, 2006, 7(2):1-44. http://www.researchgate.net/publication/42797954_MPI-DING_reference_glasses_for_in_situ_microanalysis_New_reference_values_for_element_concentrations_and_isotope_ratios

周亮亮, 魏均启, 王芳, 等.LA-ICP-MS工作参数优化及在锆石U-Pb定年分析中的应用[J].岩矿测试, 2017, 36(4):350-359. doi: 10.15898/j.cnki.11-2131/td.201701160007

Zhou L L, Wei J Q, Wang F, et al.Optimization of the working parameters of LA-ICP-MS and its application to zrcon U-Pb dating[J].Rock and Mineral Analysis, 2017, 36(4):350-359. doi: 10.15898/j.cnki.11-2131/td.201701160007

Bao Z, Zhang H, Yuan H, et al.Flux-free fusion technique using a boron nitride vessel and rapid acid digestion for determination of trace elements by ICP-MS[J].Journal of Analytical Atomic Spectrometry, 2016, 31(11):2261-2271. doi: 10.1039/C6JA00269B

He Z, Huang F, Yu H, et al.A flux-free fusion technique for rapid determination of major and trace elements in slicate rocks by LA-ICP-MS[J].Geostandards and Geoanalytical Research, 2016, 40(1):5-21. doi: 10.1111/j.1751-908X.2015.00352.x

Chen L, Liu Y, Hu Z, et al.Accurate determinations of fifty-four major and trace elements in carbonate by LA-ICP-MS using normalization strategy of bulk components as 100%[J].Chemical Geology, 2011, 284(3-4):283-295. doi: 10.1016/j.chemgeo.2011.03.007

Hou Z H, Wang C X.Determination of 35 trace elements in geological samples by inductively coupled plasma mass spectrometry[J].Journal of University of Science and Technology of China, 2007, 37(8):940-944. http://cn.bing.com/academic/profile?id=e46988f1504e666bd22cf8df0783a476&encoded=0&v=paper_preview&mkt=zh-cn

Wagner B, Nowak A, Bulska E, et al.Complementary analysis of historical glass by scanning electron microscopy with energy dispersive X-ray spectroscopy and laser ablation inductively coupled plasma mass spectrometry[J].Microchimica Acta, 2007, 162(3-4):415-424. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=e0d8e391c46e621ab58b3c8473a51ded

Supplements (0)

Cited By