LIBS for soil analysis. Dra. Débora Marcondes Bastos Pereira Milori

Transcription

1 LIBS for soil analysis Dra. Débora Marcondes Bastos Pereira Milori 1

2 PRECISION AGRICULTURE 2

3 Plant nutrition Soil density Plant Deseases Soil Texture Hydric Stress Quality of fertilizers Sensorss Phenotyping Soil ph Soil Contamination Humification Soil fertility Plant variety 3

4 Photonic sensors 4

5 Laser Induced Breakdown Spectroscopy LIBS 5

6 THE GROWTH RATE OF SCIENTIFIC PUBLICATION NUMBER OF PUBLIS HED PAPERS

7

8 LIBS: Advantages and Disadvantages Advantages Simple experimental setup Fast and cheap (large scale measurements and monitoring) Simultaneous multi-elemental analysis Disadvantages Difficulty in obtaining adequate standards (semi-quantitative) Significant interference effects Weak signal on aqueous samples LIBS typically uses very small samples of material (~ 0.1 ng to 1 µg) Versatile sampling of solids, gases or liquids Little or no sample preparation is required With specialized optics or a mechanically positioned specimen stage, the laser can be scanned over the surface of the specimen allowing spatially resolved chemical analysis and the creation of 'elemental maps'. Portable LIBS systems are more sensitive, faster and can detect a wider range of elements (particularly the light elements) than competing techniques such as portable x-ray fluorescence. LODs are not as good as those techniques which use digestion and liquid samples (wellestablished) It is subject to variation in the laser spark and resultant plasma which often limits reproducibility. The accuracy of LIBS measurements is typically better than 10% and precision is often better than 5%. The detection limits for LIBS vary from one element to the next depending on the specimen type and the experimental apparatus used. Even so, detection limits of 1 to 30 ppm by mass are not uncommon, but 8 can range from >100 ppm to <1 ppm.

9 Laser Ablation - target Laser E

10 BASIC CONCEPTS OF LIBS t=0 ns t < 1 ns t < 1 ns t < 1 ns t ~ 5 ns t ~ 50 ns t ~ 5 µs t ~ 20 µs t ~ 50 µs 10

11 11

12 Ionic and atomic Emissions 12

13 Qualitative X Quantitative 13

14 Curiosity Rover 14

15 Mirã A Robot for Precision Agriculture

16 TEAM 16

17 Quantitative Measurements Calibration free Inner pattern Calibration Reference tecnique 17

18 LIBS 18

19 Samples Sólida Líquida Gasosa 19

20 20

21 Vacuum Atm Atm control 21

22 Emission spectra for stainless under different atmospheres 22

23 Sample Homogeneity average spectrum 23

24 Delay Time 24

25

26 26

27 27

28 LIBS: Potential for soil analysis 28

29 Soil carbon quantification Quantification of Nutrients in soil Quantification of Contaminants in soil Evaluation of soil ph Evaluation of soil texture Information about chemical structure of SOM... 29

30 LIBS: Quantification of soil carbon 30

31 Commercial LIBS system Spectrometers manufactured by Ocean Optics model LIBS2500 spectral range: nm Resolution: 0.1 nm Laser manufactured by Quantel model Big Sky Laser Ultra50 single-pulse energy 50 mj pulse duration 8ns Delay time: 3 µs 31

32 Samples Embrapa Southeastern Livestock; Four areas of pasture and native forest; Dystrophic Red Latosol and Brachiaria decumbens vegetation; Six trenches in each area: A1 - Intensive irrigated and high animal stocking; A2 - Intensive dryland and high animal stocking; A3 - In recovery and average stocking and A4 - Degraded and average animal stocking. A2 A1 A4 32 Mata A3

33 Samples Trenches with 1.20m depth in intervals of: 0-5, 5-10, 10-20, 20-30, 30-40, 40-60, and cm 33 42

34 Sample preparation: Drying at room temperature Cleaning and removing plant residues Homogenization of samples Soil pressing in pellets (8 ton) 5g soil sifting in 100 mesh sieve (for pellets production and CHNS measurements) Grinding and sifting of soil samples in a 2mm sieve 34

35 Elemental Analyser (CHN) - Analyses in duplicate; - Tin capsule (catalyst) containing 10mg of sample; 35 44

36 Typical soil spectrum obtained by LIBS Main carbon emission lines at and nm 36

37 NIST database - Atomic Lines (National Institute of Standards and Technology) 37 NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY (NIST). Atomic spectra database lines form. Gaithersburg, Disponível em: < lines_form.html>

38 Carbon emission line at nm is interfered by an Al emission line 38 NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY (NIST). Atomic spectra database lines form. Gaithersburg, Disponível em: < lines_form.html>

39 Applied Optics, vol 53, nº 10, p. 2170, NICOLODELLI, G.; MARANGONI, B. S.; CABRAL, J. S.; VILLAS-BOAS, P. R.; SENESI, G. S.; SANTOS, C. H.; ROMANO, R. A.; SEGNINI, A.; LUCAS, Y.; MONTES, C. R.; MILORI, D.M.B.P. Quantification of total carbon in soil using Laser-Induced Breakdown Spectroscopy (LIBS): a method to correct interference lines. Applied Optics, v. 53, n.10, p , 2014

40 LIBS measurements 3, , ,0 Intensidade (u.a.) C Al C LIBS (%) 1,5 1,0 0, Comprimento de Onda (nm) 0,0 0,0 0,5 1,0 1,5 2,0 2,5 3,0 C CHN (%) MODELO LINHA 193,04 nm R=0.94 ERM = 22% MODELO PLS faixa espectral nm R=0.95 ERM = 20% 40

41 41

42 LIBS: Nutrients e Contaminants in soils 42

43 43

44 LIBS + ARTIFICIAL NEURAL NETWORKS FOR METAL QUANTIFICATION Analyte Chosen lines (nm) Ba (I) 307,27; (II) 413,19; (II) 455,28; (I) 553,49 Co (II) 234,90; (I) 241,09; (I) 242,46; (I) 344,43; (I) 347,56; (I) 356,98 Cu (I) 217,84; (II) 219,27; (I) 223,16; (I) 324,83; (I) 327,18 Cr (I) 276,81; (II)283,64; (I) 360,63; (I) 429,10; (I) 520,61; (I) 521,05 Mn (II) 257,46; (II) 259,33; (I) 279,60; (II) 344,05; (I) 403,30 Ni (II) 217,63; (II) 221,43; (I) 234,39; (I) 300,25; (I) 341,32; (I) 346,16; (I) 352,60; (I) 356,52; (I) 361,84 V (II) 311,02; (II) 311,93; (I) 318,60; (II) 319,04; (I) 385,56; (I) 412,78; (I) 413,19; (I) 437,99; (I) 439,53; (I) 609,08 Zn (II) 202,56; (I) 213,91; (II) 249,91; (I) 307,47; (I) 328,21; (I) 468,20; (I) 472,26; (II) 491,34; (I) 636,33 44

45 LIBS + NEURAL NETWORKS FOR METAL QUANTIFICATION ICP OES LIBS-Linear Fit LIBS-MLP ICP OES LIBS-Linear Fit LIBS-MLP ICP OES LIBS-Linear Fit LIBS-MLP Ba (mg kg -1 ) Mn (mg kg -1 ) V (mg kg -1 ) Validation Samples Validation Samples Validation Samples 80 ICP OES LIBS-Linear Fit LIBS-MLP ICP OES LIBS-Linear Fit LIBS-MLP ICP OES LIBS-Linear Fit LIBS-MLP Ni (mg kg -1 ) 40 Cu (mg kg -1 ) Zn (mg kg -1 ) Validation Samples Validation Samples Validation Samples 45 FERREIRA; EC; MILORI, D.M.B.P; FERREIRA, EJ; DOS SANTOS, LM; MARTIN-NETO, L.; NOGUEIRA, ARA. Evaluation of laser induced breakdown spectroscopy for multielemental determination in soils under sewage sludge application. Talanta 07/2011; 85(1):

46 PEARSON S COEFFICIENT, ERROR, LOD E ACCEPTABLE LIMIT IN SOIL (BRAZILIAN LAWS) : 0.99 Ba, error 8.0%, LOD = 8.01 mg kg -1, Limit in soil 300 mg kg -1; 0.99 Cu, error 6.4%, LOD = 9.94 mg kg -1, Limit in soil 200 mg kg -1 ; 0.99 Co, error 14%, LOD = 9.33 mg kg -1 kg -1, Limit in soil 35 mg kg -1 ; 0.99 Mn, error 10%, LOD = 114 mg kg -1, Limit in soil? 0.98 Ni, error 20%, LOD = 7.86 mg kg -1, Limit in soil 70 mg kg -1 ; 0.99 V, error 4.5%, LOD = 46.9 mg kg -1, Limit in soil? 0.98 Zn, err 18%, LOD = 30.7 mg kg -1, Limit in soil 450 mg kg -1 ; 46

47 DP- LIBS 47

48 DP-LIBS 48

49 49

50 Typical Soil Spectrum 59/27 50

51 51

52 Espectros LIBS utilizando um sistema DP LIBS para diferentes tempos de atraso. 52

53 LOD e LOQ para diferentes linhas de emissão encontradas em fertilizantes utilizando as técnicas SP e DP LIBS. 53

54 54

55 55

56 56

57 57

58 58

59 Intensity (a.u.) Ca II Al I Al I Ca II Wavelength (nm) ph predicted R = 0.82 MAE = ph reference value

60 60

61 61

62 62

63 Gaussian function fitting data of the Hg II peak transition for the 1000 mgkg -1 Hg content sample to remove the offset. 63

64 64

65 Acknowledgments 65

66 Foto do grupo 66

67 THANK YOU!!!! 67