In-situ analytical study of bricks exposed to marine environment using hand-held X-ray fluorescence spectrometry and related laboratory techniques

1 In-situ analytical study of bricks exposed to 1 marine environment using Hand-Held X-ray 2 fluorescence spectrometry and related 3 laboratory techniques 4 5 Héctor Morillasa*, Cristina García-Florentinoa, Iker Marcaidaa, 6 Maite Magureguib, Gorka Aranaa, Luis F.O. Silvac and Juan Manuel Madariagaa 7 8 aDepartment of Analytical Chemistry, Faculty of Science and Technology, University of the Basque 9 Country UPV/EHU, P.O. Box 644, 48080 Bilbao, Basque Country, Spain 10 e-mail: hector[email protected]s11 bDepartment of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country UPV/EHU,12 P.O. Box 450, 01080 Vitoria-Gasteiz, Basque Country, Spain13 cResearch Group in Environmental Management and Sustainability, Faculty of Environmental Sciences,14 Universidad De La Costa, Calle 58 #55-66, 080002 Barranquilla, Atlántico, Colombia15 16 ABSTRACT 17 18 In this work, the degradation processes that take place in bricks exposed to marine 19 environments have been studied. Taking into account the importance of this building 20 material where the silicates present in the final product act as stabilizer in the porous 21 material itself, it is necessary to understand the decay processes that occur in these 22 aggressive environments. As is known, the marine aerosol carries different types of salts, 23 such as chlorides, sulfates, nitrates, etc., present in surrounding environment exerting a 24 negative influence on the materials producing cracking and disintegration processes of 25 the material and consequently loss of brick wall stability. Nowadays the development of 26 portable devices is taking much more importance helping researchers to resolve problems 27 in the field in a fast and easy way. In order to extract fast and satisfactory results about 28 the conservation state of different bricks from Punta Begoña Galleries (Getxo, Basque 29 Country, Spain), an in-situ analytical methodology was developed based on the use of 30 hand-held Energy Dispersive X-ray fluorescence spectrometry (HH-ED-XRF) assisted 31 with other laboratory techniques (µ-ED-XRF and X-Ray Diffraction) in order to 32 corroborate and complement the information obtained in-situ. This construction 33 undergoes the influence of marine aerosol, industrial port, power generation plants, and 34 a fuel refinery among others. The pathologies visually observable in these bricks are 35 disintegration, breakup and detachment of the bricks. The presence of deterioration 36 compounds in the bricks has been studied according to the orientations of the bricks inside 37 the construction. 38 This is the accepted manuscript of the article that appeared in final form in Spectrochimica Acta Part B: Atomic Spectroscopy 146 : 28-35 (2018), which has been published in final form at https://doi.org/10.1016/j.sab.2018.04.020. © 2018 Elsevier under CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) 2 39 Keywords: Brick; in-situ analysis; marine environment; HH-ED-XRF, calcium 40 silicate. 41 42 43 1. Introduction 44 Since ancient times, bricks are some of the most used materials in constructions. In 45 5,000 BC, the brick appeared as building material, and around 3,500 BC, the fired brick 46 was finally created. Thanks to the industrialization in the 19th century, the use of brick as 47 building material increased and acquired great importance, being one of the most used 48 material for the building constructions [1]. 49 Bricks used for constructions are made from clay, which is kneaded with 20-25% water. 50 The resulting paste is molded and the bricks obtained are dried in the air [2]. Although 51 several processes of bricks production exist, various mixtures of raw clays (mainly 52 composed of illite-chlorite, quartz, calcite and/or dolomite, sodium and potassium 53 feldspars, and iron oxides/hydroxides) are fired at about 900–1025°C in order to obtain 54 the final brick [3]. Their characteristic reddish-orange colour, is indicative of the amount 55 and type of iron oxides and oxyhidroxides present in the clay used for its manufacture 56 [4]. However, other chemical elements such as Sb, Pb, Ca, Fe and traces of Cu have a key 57 role in the reddish orange colour of the bricks [5]. In this sense, the composition and 58 microstructure of the bricks are some of the most important characteristics to preserve 59 their durability [6, 7]. Moreover, the clay must have a low amount of impurities and 60 especially must have a low content of calcium carbonate to be plastic enough, and to 61 avoid the presence of unreacted lime after firing. The presence of calcium carbonate in 62 the bricks can cause cracks when the clay is mixed with water. For this reason, usually 63 the clay must contain calcium carbonate in a proportion of less than 8-10%. During firing, 64 a series of mineralogical transformations take place depending essentially on the initial 65 composition, kiln temperature, heating grade, firing time and prevalence of oxidizing or 66 reducing reactions [8-10] redefining the mineralogical composition and microstructure. 67 In this way, after firing at 900-1025°C, kaolin is dissociated into silica and alumina and 68 also into calcium and aluminum silicate. One of the critical factors in the conservation 69 state of bricks is the content of calcium silicate that provides stability to the structure and 70 3 resistance to temperature changes. Consequently, the bricks fire or cooking temperature 71 is established as one of the most important steps in the bricks construction [11, 12]. 72 Bricks, as all building materials, can experiment different chemical reactions that could 73 promote changes in their appearance and conservation state. Bricks can suffer the effect 74 of humidity [13,14], biocolonizations [15], the attack of atmospheric acidic gases [16], 75 infiltrations by aqueous solutions [17-19], the impact of marine aerosols [20, 21], dry and 76 wet depositions [22-24], freeze-thaw cycles [25], etc. These sources of deterioration, can 77 promote several chemical and physical problems as well as efflorescences formation [17], 78 loss of material [26], etc. 79 In the literature, there are many works that analyze bricks in order to extract conclusions 80 about their conservation state [27, 28], the provenance [29], original composition [30], 81 the brick composition influence on decay compounds [31], etc. Moreover, different 82 techniques such as X-Ray diffraction (XRD) [32], Raman spectroscopy [33, 1, 19], 83 infrared spectroscopy [34, 35], Inductively Coupled Plasma Mass Spectrometry (ICP84 MS) [36], Laser ablation Inductively Coupled Plasma Mass spectrometry (LA-ICP-MS) 85 combined with Instrumental Neutron Activation Analysis (INAA) and X-ray 86 fluorescence (XRF) [37], XRF [38] and Laser-induced breakdown spectroscopy (LIBS) 87 [39], have been used to carry out these types of analyses. In all these case studies, the 88 analytical instruments used were laboratory benchtop devices and there are no works that 89 use hand-held/portable instruments to analyze bricks and to evaluate their pathologies. 90 Sometimes the extraction of samples is a critical step, mainly due to sampling restrictions. 91 For this reason, the application of portable devices is taking much more importance, 92 helping researchers to carry out different in-situ analyses obtaining satisfactory results 93 without the necessity of taking samples [40-42, 18]. Example of these types of devices 94 are the hand-held Energy Dispersive X-Ray fluorescence spectrometers (HH-ED-XRF), 95 for which its use is being increased in the last years, because they are user friendly and 96 offer results in few seconds or minutes [43-45]. As a consequence of this, many 97 worldwide scientific groups are improving and developing new analytical methodologies 98 based on these kind of devices [46, 47]. 99 In this work, a simple, fast and non-destructive methodology based on the use of a hand100 held Energy Dispersive X-ray fluorescence spectrometer (HH-ED-XRF) was applied to 101 perform a field analysis of bricks from Punta Begoña Galleries (Getxo, Basque Country, 102 Spain) which show different deterioration degrees depending mostly on their location in 103 4 front of the industrial port of Bilbao and diverse factories emitting atmospheric pollutants. 104 In order to confirm and complement conclusions extracted in-situ, additional analyses 105 were conducted in the laboratory using micro-ED-XRF spectrometry and X-Ray 106 diffraction (XRD) techniques. 107 2. Experimental 108 2.1. Punta Begoña Galleries 109 110 Punta Begoña Galleries are located in Getxo, close to Ereaga beach, in Biscay (Basque 111 Country, Spain). These galleries were built in 1918 by an industrial tycoon, Horacio 112 Echevarrieta [48]. It is one of the most significative construction in Biscay and Basque 113 Country of the 20th century. Nowadays, it is abandoned and it is poorly preserved (see 114 Fig. 1). The construction is composed by two galleries: the upper gallery or “Northwest 115 Gallery” (NG) and the lower gallery or “Southwest Gallery” (SG). The NG is oriented to 116 the northwest, and the SG is oriented to the southwest. All the construction is placed in 117 front of the sea; there is a beach in front of the NG and a leisure port in front of the SG, 118 together with the industrial port of Bilbao at 1-8 km and several factories (refinery, power 119 station plant of liquid hydrocarbons, and metallurgical companies), emitting acid gases 120 and metallic particles to the atmosphere, at not more than 10 km from the building. The 121 whole building is made by different materials such as concrete, ceramic, mortar, cement, 122 limestone and brick. 123 2.2. In-situ analyses 124 125 The in-situ analyses were carried out in both galleries by means of HH-ED-XRF. For this 126 purpose, seven areas from the Northwest Gallery (coded samples NG1-NG7) and 127 additional seven from the Southwest Gallery (coded samples SG1-SG7) were selected 128 (see Fig. 1). As can be observed in Fig. 1, bricks show a better or worse conservation state 129 depending on the orientation. 130 2.3. Instrumentation 131 The in-situ elemental analysis of the bricks was carried out using an XMET5100 (Oxford 132 Instruments, UK) hand-held energy dispersive X-Ray fluorescence spectrometer (HH133 ED-XRF). The instrument is equipped with an Rh tube working at a maximum voltage of 134 45 kV. The spot size of the emitted X-Ray beam is 9 mm. The analyzer includes a Peltier135 5 cooled silicon drift detector (SDD) of high resolution that is able to provide an energetic 136 resolution of 150 eV (calculated for the Mn Kα line). The analyzer contains a PDA to 137 control the spectrometer and also to save the spectra and semi-quantitative information. 138 To determine the presence of the heaviest elements (Z>Ti) the voltage and current of the 139 X-Ray tube was set at 40 kV and 15 µA respectively and the spectra were acquired during 140 100 seconds (real time) in order to improve the limit of detection for the identification of 141 trace elements. Additionally, to remove the Bremsstrahlung and possible Bragg 142 diffraction peaks, a 500 µm Al filter was used. In order to improve the detection of the 143 lighter elements (Z<Ti), additional measurements were performed without the Al filter 144 and at lower voltage (13 kV) and higher current (40 µA) during 70 seconds. In order to 145 determine possible contributions from detector materials and possible contaminations of 146 the XRF analyzer window, 20 repetitive spectra of an instrumental blank (a PTFE block) 147 were acquired before each measurements batch. For the repetitive measurements, the 148 same spectral conditions (voltage, current, filter and test time) as those used for the 149 analysis of the bricks were considered. Although the software is based on the use of 150 Fundamental Parameters quantification methods, in this work, the net counts of Kα lines 151 of each detected element in the spectrum were considered following a normalization 152 process. See elsewhere for further details [43]. To extract representative results, ten 153 measurements (9 mm area each one) were performed randomly distributed on seven areas 154 from the NG (NG1-NG7) and on additional seven from the SG (SG1-SG7). In order to 155 evaluate the elemental composition of the bricks without extracting any sample, semi156 quantitative information given by the HH-ED-XRF was avoided. Instead of that, a 157 specific spectral data treatment based on the normalization of the net counts of each 158 detected element was conducted [43]. For all the detected elements, net counts associated 159 with Kα line were considered, except for Pb for which Lβ line was used. Considering that 160 Fe is a major element which showed an almost constant concentration in all the measured 161 areas, its Fe Kα line was used to normalize the net counts of light elements (Z≤20) in the 162 spectra. For the heaviest elements (Z ≥ 26), the net counts of their Kα lines were 163 normalized against the net counts of the Compton line (incoherent scattering). This 164 normalization process was done in order to correct possible matrix effects and variations 165 in the positioning of the measuring sampling interface. In order to avoid spectral 166 interferences between the As K1 and Pb L1 lines, Kβ1 (11.7 keV) and Pb Lβ1 (12.6 keV) 167 lines were considered for As and Pb respectively. 168 6 In order to extract more conclusions, the elemental composition was also studied in the 169 laboratory by using the M4 TORNADO Energy Dispersive X-ray Fluorescence 170 spectrometer (Bruker Nano GmbH, Berlin, Germany). This instrument is equipped with 171 a micro-focus side window Rh X-ray tube powered by a low-power HV generator and 172 cooled by air. The spectral acquisitions in this work were performed at the maximum 173 voltage (50 kV) and current (600 μA) that the X-ray source allows. This equipment can 174 work using polycapillar lenses, which allow performing both single point measurements 175 down to 25 μm of lateral/spatial resolution, and Hyper Maps to determine the distribution 176 of each element detected in the collected fragments. A XFlash® silicon drift detector with 177 30 mm2 sensitive area and energy resolution of 145 eV for Mn-Kα was used for 178 fluorescence radiation detection. In order to improve the detection of the lightest elements 179 (Z<11), filters were not used and measurements were acquired under vacuum (20 mbar). 180 The vacuum was achieved with a diaphragm pump MV 10 N VARIO-B. The live time 181 used for each single point measurement was 200 seconds. Two video-microscopes were 182 used to focus the area under study, a low magnification (1 cm2 areas) one for the 183 exploration of the sample and a higher magnification one (1 mm2 areas) for the final 184 focusing. In order to obtain the Hyper Maps, the Kα line of each element was used after a 185 previous elemental assignation and deconvolution of the spectral information using the 186 M4 TORNADO software (Bruker Nano GmbH, Berlin, Germany). 187 Finally, XRD analyses were performed with a powder diffractometer PANalytical X´Pert 188 PRO, equipped with a copper tube (λCuKαmedia= 1.5418 Å, λCuKα1= 1.54060 Å, λCuKα2= 189 1.54439 Å), vertical goniometer (Bragg-Brentano geometry), programmable divergence 190 aperture, automatic interchange of samples, secondary monochromator from graphite and 191 PixCel detector. The measurement conditions were 40 kV and 40 mA, with an angular 192 range (2θ) scanned between 5 and 70°. For the data treatment of the diffractograms and 193 the identification of the present mineral phases, the specific software X`Pert HighScore 194 (PANalytical) in combination with the specific powder diffraction file database 195 (International Centre for Diffraction Data - ICDD, Pennsylvania, USA) was used. 196 197 7 198 Fig. 1. Punta Begoña Galleries (Getxo, Basque Country, north of Spain) and the analyzed 199 brick areas from their Northwest and Southwest Galleries (NG and SG). 200 201 202 3. Results and discussion 203 204 3.1. HH-ED-XRF analyses 205 To simplify the visualization of the normalized areas related to the average of the 10 206 spectral measurements from each studied area, they are presented as a bar graph (see Fig. 207 2). In Table S1 from Appendix, the normalized counts for all the elements detected in the 208 measured areas are presented as the average of the ten repetitive measurements on each 209 area together with their respective standard deviations. Among all the detected elements, 210 Cl, Br and Sr can be present in the brick coming from the marine aerosol [48-50]. The 211 last element could be also naturally present in the bricks. As it has been explained in the 212 8 experimental section, to avoid false positives the background offered by the instrument 213 (instrumental blank) was evaluated. This issue can be considered of special interest 214 considering the interference caused by the Rh L coming from the tube in the Cl K line. 215 The normalized counts of Cl, Br and Sr for all the areas in the NG and SG are quite similar 216 (see Fig. 2A), although a little bit higher values were registered in some measured areas 217 from the SG. 218 In all the analyzed areas, S was also detected. The presence of this element in the bricks 219 could suggest the possible presence of sulfates. These compounds can be present in the 220 bricks due to the influence of infiltration waters rich in sulfates or as a consequence of 221 the impact of atmospheric SOx. Calcium carbonate that can be present on them can react 222 with the sulfates in the first case and with the H2SO4 coming from the atmospheric SOx. 223 S normalized counts values are higher in the SG than in the NG, except for the case of 224 NG1 and NG7 areas. 225 Apart from elements that can be present in the bricks due to the influence of the 226 surrounding atmosphere, those related with the original composition were also evaluated. 227 In Fig. 2B, the normalized counts of these kind of elements (Al, Si, K, Ca and Fe) are 228 presented. The normalized counts of Al and Si are quite similar except for the NG7 area, 229 where a little bit higher values were registered. The presence of both elements in the 230 bricks is related with the content of silicates and aluminosilicates on them. The results 231 obtained for K are quite similar, revealing similar normalized counts values in all the 232 areas, except in the NG1 area, which shows higher values than the rest of the areas. 233 According to Ca, the highest values were registered in the SG, although in the NG high 234 values were also obtained for the NG1 and NG7 areas, as it happened for Ca. As has been 235 previously mentioned, the presence of Fe is quite similar in all the measured areas. This 236 element is related with the presence of iron oxides and oxy-hydroxides in the bricks, 237 compounds that give the characteristic orange-red color to the analyzed bricks. 238 The normalized counts of Ti, V, Cr, Mn, Ni, Cu, Zn and Pb are presented in Fig. 2C. Ti, 239 V, Cr and Mn show interference once with each other’s. Thus, these interferences could 240 alter the conclusions that can be extracted analyzing the normalized counts. Leaving aside 241 this observation, the normalized counts of each element is similar in all the analyzed 242 areas, suggesting that the main contribution of these metals come from the natural raw 243 material itself. This tendency was not observed for Pb. In this case, higher normalized 244 9 counts were obtained in the areas from NG than in areas from SG; particularly, this 245 element was not identified in the SG2 area. This observation could suggest a possible 246 deposition of Pb coming from the surrounding atmosphere, especially in the bricks from 247 the NG area. It is necessary to remark that there are metallurgical industries from the 248 metropolitan Bilbao, not far away from the Galleries, and they contribute to emissions of 249 metallic particles, being possible their subsequent dry deposition [22, 23, 45]. 250 Finally, for the rest of the detected elements (see Fig. 2D) the obtained values were similar 251 in all the measured areas except for Zr and Sn. The normalized counts of Zr are similar 252 in all the areas, except in NG7 area, where there is no presence of this element. Finally, 253 it is necessary to remark that Sn was detected in all the NG areas but only in few areas 254 from the SG was detected (SG5 and SG7) 255 256 257 Fig. 2. Bar charts representing the logarithm of the normalized areas related to the average 258 of the 10 spectral measurements obtained with HH-ED-XRF on each measured area 259 together with their error bars of A) S, Cl, Br and Sr; B) Al, Si, K, Ca, Fe; C) Ti, Ni, Cu, 260 Zn, Pb and D) Rb, Y, Zr and Sn. 261 3.2. Principal Component Analysis (PCA) of in-situ ED-XRF results 262 In order to extract additional conclusions, the data matrix (normalized counts of NG and 263 SG areas, 14 areas x 10 analysis each) was subjected to Principal Component Analysis 264 16 Acknowledgements 429 This work has been funded by the Spanish Ministry of Economy, Industry and 430 Competitiveness and the European Regional Development Fund (ERDF/FEDER), 431 through the project MADyLIN (Grant No. BIA2017-87063-P, AEI-EU/FEDER) and by 432 the cooperation agreement between the University of the Basque Country (UPV/EHU) 433 and the City Council of Getxo (OTRI2014-0639). Technical support provided by General 434 X-ray Service of the SGIKer (UPV/EHU, Ministry of Economy and Competitiveness of 435 Spain, Basque Government, ERDF and European Social Fund) is also gratefully 436 acknowledged. 437 438 Appendix A. Supplementary data 439 Supplementary data to this article can be found online at DOI:.. 440 441 442 443 References 444 [1] M. Maguregui, A. Sarmiento, R. Escribano, I. Martinez-Arkarazo, K. Castro, J.M. 445 Madariaga, Raman spectroscopy after accelerated ageing tests to assess the origin of some 446 decayed products found in real historical bricks affected by urban polluted atmospheres, 447 Anal. Bioanal. Chem. 395 (2009) 2119-2129. 448 [2] A. Angiolani, Introducción a la química Industrial. Fundamentos químicos y 449 tecnológicos. Edit. Andres Bello. Santiago de Chile, Chile, 1960. 450 [3] A. Viani, K. Sotiriadis, A. Len, P. Šašek, R. Ševčík, Assessment of firing conditions 451 in old Fired-clay bricks: The contribution of X-ray powder diffraction with the Rietveld 452 method and small angle neutron scattering, Mater. Charact. 116 (2016) 33-43. 453 [4] R. Kreimeyer, Some Notes on the Firing Color of Clay Bricks, Appl. Clay Sci. 2 454 (1987) 175-183. 455 17 [5] P. Holakooei, A multi-spectroscopic approach to the characterization of early glaze 456 opacifiers: Studies on an Achaemenid glazed brick found at Susa, south-western Iran 457 (mid-first millennium BC), Spectrochim. Acta A 116 (2013) 49-56. 458 [6] G. Cultrone, I. Sidraba, E. Sebastián, Mineralogical and physical characterization of 459 the bricks used in the construction of the “Triangul bastion”, Riga (Latvia), Appl.Clay 460 Sci. 28 (2005) 297–308. 461 [7] K. Elert, G. Cultrone, C. Rodriguez Navarro, E. Sebastián, Durability of bricks used 462 in the conservation of historic buildings—influence of composition and microstructure, 463 J. Cult. Herit. 4 (2003) 91–99. 464 [8] R. Fort, M. Alvarez de Buergo, M.C. López de Azcona, F. Mingarro, M.J. Varas, J. 465 Soriano, Caracterización de la Fábrica de Ladrillo del Palacio del Infante Don Luis, 466 Boadilla del Monte, Madrid, Bol. Soc. Esp. Ceram. Vidrio 43 (2004) 578-582. 467 [9] M. Maggetti, Phase Analysis and its Significance for Technology and Origin, J.S. 468 Olin, A.D. Franklin (Eds.), Archaeological Ceramics, Smithsonian Institution Press, 469 Washington D.C (1982), pp. 121-133. 470 [10] L. Maritan, L. Nodari, C. Mazzoli, A. Milano, U. Russo, Influence of firing 471 conditions on ceramic products: experimental study on clay rich in organic matter, Appl. 472 Clay Sci. 31 (2006) 1-15. 473 [11] B. Bauluz, M.J. Mayayo, A. Yuste, C. Fernandez-Nieto, J.M. Gonzalez Lopez, TEM 474 study of mineral transformations in fired carbonated clays: relevance to brick making, 475 Clay Miner. 39 (2004) 333–344. 476 [12] G. Cultrone, E. Sebastián, K. Elert, M.J. de la Torre, O. Cazalla, C. Rodriguez477 Navarro, Influence of mineralogy and firing temperature on the porosity of bricks, J. Eur. 478 Ceram. Soc. 24 (2004) 547–564. 479 [13] H. Morillas, M. Maguregui, O. Gómez-Laserna, J. Trebolazabala, J.M. Madariaga, 480 Characterisation and diagnosis of the conservation state of cementitious materials 481 exposed to the open air in XIX century lighthouses located on the coast of the Basque 482 Country: The case of Igueldo lighthouse, San Sebastian, North of Spain, J. Raman 483 Spectrosc. 43 (2012) 1630-1636. 484 18 [14] H. Morillas, M. Maguregui, O. Gómez-Laserna, J. Trebolazabala, J.M. Madariaga, 485 Could marine aerosol contribute to deteriorate building materials from interior areas of 486 lighthouses? An answer from the analytical chemistry point of view, J. Raman Spectrosc. 487 44 (2013) 1700–1710. 488 [15] H. Morillas, M. Maguregui, I. Marcaida, J. Trebolazabala, I. Salcedo, J.M. 489 Madariaga, Characterization of the main colonizer and biogenic pigments present in the 490 red biofilm from La Galea Fortress sandstone by means of microscopic observations and 491 Raman Imaging, Microchem. J. 121 (2015) 48–55. 492 [16] A. Sarmiento, M. Maguregui, I. Martinez-Arkarazo, M. Angulo, K. Castro, M.A. 493 Olazabal, L.A. Fernandez, M.D. Rodriguez-Laso, A.M. Mujika, J. Gomez, J.M. 494 Madariaga, Raman spectroscopy as a tool to diagnose the impacts of combustion and 495 greenhouse acid gases on properties of Built Heritage, J. Raman Spectrosc. 39 (2008) 496 1042-1049. 497 [17] H. Morillas, M. Maguregui, J. Trebolazabala, J.M. Madariaga, Nature and origin of 498 white efflorescence on bricks, artificial stones and joint mortars of modern houses 499 evaluated by portable Raman spectroscopy and laboratory analyses, Spectrochim. Acta A 500 136 (2015) 1195-1203. 501 [18] H. Morillas, J. García-Galan, M. Maguregui, C. García-Florentino, I. Marcaida, J.A. 502 Carrero, J.M. Madariaga, In-situ multianalytical methodology to evaluate the 503 conservation state of the entrance arch of La Galea Fortress (Getxo, north of Spain), 504 Microchem. J. 128 (2016) 288-296. 505 [19] M. Maguregui, A. Sarmiento, I. Martínez-Arkarazo, M. Angulo, K. Castro, G. Arana, 506 N. Etxebarria, J.M. Madariaga, Analytical diagnosis methodology to evaluate nitrate 507 impact on historical building materials, Anal. Bioanal. Chem. 391 (2008) 1361–1370. 508 [20] H. Morillas, M. Maguregui, C. Paris, L. Bellot-Gurlet, P. Colomban, J.M. 509 Madariaga, The role of marine aerosol in the formation of (double) sulfate/nitrate salts in 510 plasters, Microchem. J. 123 (2015) 148-157. 511 [21] H. Morillas, J. García-Galán, M. Maguregui, I. Marcaida, C. García-Florentino, J.A. 512 Carrero, J.M. Madariaga, Assessment of marine and urban-industrial environments 513 19 influence on built heritage sandstone using X-ray fluorescence spectroscopy and 514 complementary techniques, Spectrochim. Acta B. 123 (2016) 76-88. 515 [22] H. Morillas, M. Maguregui, C. García-Florentino, I. Marcaida, J.M. Madariaga, 516 Study of particulate matter from Primary/Secondary Marine Aerosol and anthropogenic 517 sources collected by a self-made passive sampler for the evaluation of the dry deposition 518 impact on Built Heritage, Sci. Total Environ. 550 (2016) 285-296. 519 [23] H. Morillas, I. Marcaida, C. García-Florentino, M. Maguregui, G. Arana, J.M. 520 Madariaga, Micro-Raman and SEM-EDS analyses to evaluate the nature of salt clusters 521 present in secondary marine aerosol, Sci. Total. Environ. 615 (2018) 691-697. 522 [24] H. Morillas, I. Marcaida, M. Maguregui, J.A. Carrero, J.M. Madariaga, The influence 523 of rainwater composition on the conservation state of cementitious building materials, 524 Sci. Total Environ. 542 (2016) 716-727. 525 [25] E.M. Perez-Monserrat, F. Agua, R. Fort, M. Alvarez de Buergo, J.F. Conde, M. 526 García-Heras, Effect of manufacturing methods on the decay of ceramic materials: A case 527 study of bricks in modern architecture of Madrid (Spain), Appl. Clay Sci. 135 (2016) 136528 149. 529 [26] B. Lubelli, R.P.J van Hees, C.J.W.P. Groot, The role of sea salts in the occurrence 530 of different damage mechanisms and decay patterns on brick masonry, Constr. Build. 531 Mater. 18 (2004) 119-224. 532 [27] P. Aloise, M. Ricca, M.F. La Russa, S.A. Ruffolo, C.M. Belfiore, G. Padeletti, G.M. 533 Crisci, Diagnostic analysis of stone materials from underwater excavations: the case study 534 of the Roman archaeological site of Baia (Naples, Italy), Appl. Phys. A-Mater. 114 (2014) 535 655-662. 536 [28] A.A. El-Midany, H.M. Mahmoud, Mineralogical, physical and chemical 537 characteristics of historic brick-made structures, Miner. Petrol. 109 (2015) 733-739. 538 [29] L. Bonizzoni, A. Galli, M. Gondola, M. Martini, Comparison between XRF, TXRF, 539 and PXRF analyses for provenance classification of archaeological bricks, X-Ray 540 Spectrom.42 (2013) 262-267. 541 [30] J. Chen, M. Yan, J. Su, B. Li, J. Sun, The kiln coating formation mechanism of MgO542 FeAl2O4 brick, Ceram. Int. 42 (2016) 569-575. 543 20 [31] J-H. Chen, D-F. Liu, M-W. Yan, P. Jiang, B. Li, J-L. Sun, Influence of 544 Microstructure on Formation of Deterioration Layer in Periclase-Hercynite Bricks, 545 Refract. Ind. Ceram. 57 (2016) 267-272. 546 [32] S. Belgacem, H. Galai, H. Tiss, Qualitative and quantitative investigation of post547 mortem cement refractory: The case of magnesia-spinel bricks, Ceram. Int. 42 (2016) 548 19147-19155. 549 [33] J.M. Alia, H.G.M. Edwards, F.J. García-Navarro, J. Parras-Armenteros, C.J. 550 Sanchez-Jimenez, Application of FT-Raman spectroscopy to quality control in brick 551 clays firing process, Talanta 50 (1999) 291-298. 552 [34] V.Z. Abdrakhimov, E.S. Abdrakhimova, Phase Composition and Porosity Structure 553 of Ceramic Bricks More Than 100 Years Old: Catholic Church, Iverskiy Monastery, and 554 Church of the Nativity in Samara Oblast, Glass Ceram. 73 (2016) 111-114. 555 [35] N.A. Pérez, L. Bucio, E. Lima, E. Soto, C. Cedillo, Identification of allophane and 556 other semi-crystalline and amorphous phases on pre-Hispanic Mexican adobe earth bricks 557 from Cholula, Mexico, Microchem. J. 126 (2016) 349-358. 558 [36] D.N. Phillips, Vanadium staining in fired clay bricks, Brit. Ceram. T. 102 (2003) 559 257-260. 560 [37] N. Scheid, S. Becker, M. Duecking, G. Hampel, J. Volker Krantz, P. Watzke, P. Weis, S. 561 Zauner, Forensic investigation of brick stones using instrumental neutron activation 562 analysis (INAA), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP563 MS) and X-ray fluorescence analysis (XRF), Appl. Radiat. Isotopes, 67 (2009) 2128564 2132. 565 [38] L. Bonizzoni, ED-XRF analysis for Cultural Heritage: is quantitative evaluation 566 always essential?, J. Phys. Conf. Ser. 630 (2015) 012001/1-012001/9. 567 [39] S.S. Rai, N. K. Rai, A.K. Rai, U.C. Chattopadhyaya, Rare earth elements analysis in 568 archaeological pottery by laser induced breakdown spectroscopy, Spectroscopy Letters 569 49 (2016) 57-62. 570 [40] C. García-Florentino, M. Maguregui, H. Morillas, U. Balziskueta, A. Azkarate, G. 571 Arana, J.M. Madariaga, Portable and Raman imaging usefulness to detect decaying on 572 21 mortars from Punta Begoña Galleries (Getxo, North of Spain), J. Raman. Spectrosc. 47 573 (2016) 1458–1466. 574 [41] J.M. Madariaga, M. Maguregui, S. Fdez Ortiz-De Vallejuelo, U. Knuutinen, K. 575 Castro, I. Martinez-Arkarazo, A. Giakoumaki, A. Pitarch, In situ analysis with portable 576 Raman and ED-XRF spectrometers for the diagnosis of the formation of efflorescence on 577 walls and wall paintings of the Insula IX 3 (Pompeii, Italy), J. Raman Spectrosc. 45 (2014) 578 1059-1067. 579 [42] J.M. Madariaga, M. Maguregui, K. Castro, U. Knuutinen, I. Martinez-Arkarazo, 580 Portable Raman, DRIFTS, and XRF analysis to diagnose the conservation state of two 581 wall painting panels from Pompeii deposited in the Naples National Archaeological 582 Museum (Italy), App. Spectrosc. 70 (2016) 137-146. 583 [43] C. García-Florentino, M. Maguregui, H. Morillas, I. Marcaida, J.M. Madariaga, A 584 fast in situ non-invasive approach to classify mortars from a construction of high 585 historical value, Microchem. J. 133 (2017) 104-113. 586 [44] I. Marcaida, M. Maguregui, S. Fdez-Ortiz de Vallejuelo, H. Morillas, N. Prieto587 Taboada, M. Veneranda, K. Castro, J.M. Madariaga, In situ X-ray fluorescence-based 588 method to differentiate among red ochre pigments and yellow ochre pigments thermally 589 transformed to red pigments of wall paintings from Pompeii, Anal. Bioanal. Chem. 409 590 (2017) 3853-3860. 591 [45] H. Morillas, M. Maguregui, C. García-Florentino, J.A. Carrero, I. Salcedo, J.M. 592 Madariaga, The cauliflower-like black crusts on sandstones: A natural passive sampler to 593 evaluate the surrounding environmental pollution, Environ. Res. 147 (2016) 218-232. 594 [46] S. Pessanha, M. Alves, J.M. Sampaio, J.P. Santos, M.L. Carvalho, M. Guerra, A 595 novel portable energy dispersive X-ray fluorescence spectrometer with triaxial geometry, 596 J. Inst. 12 (2017) P01014/1-P01014/13. 597 [47] S. Pessanha, A. Samouco, R. Adão, M.L. Carvalho, J.P. Santos, P. Amaro, Detection 598 limits evaluation of a portable energy dispersive X-ray fluorescence setup using different 599 filter combinations, X-ray Spectrom. 46 (2017) 102-106. 600 [48] B. Estornés Lasa, in Horacio Echevarrieta Maruri, Auñamendi Eusko Entziklopedia, 601 Euskomedia fundazioa, Donosti, 2008. 602 22 [49] S-H. Zhang, G-P. Yang, H-H. Zhang, J. Yang, Spatial variation of biogenic sulfur in 603 the south Yellow Sea and the East China Sea during summer and its contribution to 604 atmospheric sulfate aerosol, Sci. Total. Environ. 488-489 (2016) 157-167. 605 [50] K. Ballschmiter, Pattern and sources of naturally produced organohalogens in the 606 marine environment: biogenic formation of organohalogens, Chemosphere 52 (2003) 607 313-324. 608 [51] F. Moreno, S.A.G. Vilela, A.S.G. Antunes, C.A.S. Alves, Capillary-rising salt 609 pollution and granitic stone erosive decay in the parish church of Torre de Moncorvo (NE 610 Portugal)-implications for conservation strategy, J.Cult. Herit. 7 (2006) 56-66. 611 [52] M. Maguregui, R. Tagliapietra, M. Angulo, I. Martinez-Arkarazo, K. Castro, J.M. 612 Madariaga, A. Brooker, Identification of historical bricks degradation products by means 613 of Combined Raman spectroscopy and scanning electron microscopy, in Conservation 614 Science 2007 Publisher: Archetype, UK, London, Editors: J.H. Townsend, L. Toniolo, F. 615 Capitelli, pp. 212-219. 616 617 618 FIGURE CAPTIONS 619 620 Fig.1. Punta Begoña Galleries (Getxo, Basque Country, north of Spain) and the analyzed 621 brick areas from their Northwest and Southwest Galleries. 622 Fig.2. Bar charts with normalized areas related to the average of the 10 spectral 623 measurements obtained with HH-ED-XRF and their error bars of A) S, Cl, Br and Sr; B) 624 Al, Si, K, Ca ,Fe ; C) Ti, Ni, Cu, Zn, Pb and D) Rb, Y, Zr and Sn. 625 Fig.3. Correlation graph of the Ca and S normalized counts and analyzed areas. 626 Fig.4. μ-ED-XRF imaging of one of the analyzed brick observing the elemental 627 distribution of different elements. (For interpretation of the references to color in this 628 figure legend, the reader is referred to the web version of this article). 629 630