基于近红外光谱的象牙鉴定

doi:10.3964/j.issn.1000-0593(2023)08-2397-10

Abstract
References
Related Citation (15)

Download: PDF (27134 KB)
Export: BibTeX | EndNote (RIS)

Abstract The trade of elephant ivory (from now on referred to as ivory) and its products has been completely banned in China, but the smuggling has not stopped. The identification of ivory is an important part of the fight against smuggling. The ivory objects can be identified visually if characteristic features, such as the Schreger pattern, on the cross-sections can be observed. However, if it does not have the features or disappears after carving, the sample is difficult to identify by morphology. When the morphological method is not adequate, molecular biology-based method is an alternative. However, since the extremely low DNA content, extracting DNA from ivory is not easy. Some scholars have distinguished ivory and the analogues (teeth of other animals) by using the Raman spectrum and the short wave region（780~1 100 nm）of the near-infrared (NIR) spectrum. In this study, an identification method of ivory was established by establishing a NIR spectroscopy identification model, based on the spectrum region from 1 000 to 1 800 nm. Taking African elephant (Loxodonta spp.) ivory, Asian elephant (Elephas maximus) ivory and mammoth (Mammuthus spp.) ivory as the calibration set and other non-ivory products, including sperm whale (Physeter macrocephalus) teeth, hippopotamus (Hippopotamus amphibius) teeth, taguanut (phyelephas macrocarpa), ivory plastic imitation, etc. as the verification set, a total of 383 NIR spectra of 230 samples were collected. By comparing the spectral data of ivory products with different colors and thicknesses, it was found that the color and thickness of the ivory will affect the analysis results. Scanning the parts with typical color of the substance and the parts with the thickness greater than 1 mm is recommended. Based on the spectra in the regions of 1 160~1 200, 1 430~1 500, 1 680~1 710 and 1 720~1 750 nm, and the SIMCA (soft independent modeling by class analogy) qualitative analysis method, a calibration model for predicting ivory or non-ivory by NIR spectroscopy was developed. After balancing the false positive rate and false negative rate, it was deduced that the best principal factor of this model was 2 and the F value was 0.21. When applying the model, the recognition accuracy of ivory was 100%; all the animal horn, plastic and ivory fruit products could be accurately identified as non-ivory with 100% accuracy. However, the teeth of other animals with similar ivory textures, such as boar teeth and sperm whale teeth, tended to be mistaken for ivory by the model; consequently, further testing by other methods was required for these substances. The spectral model method is simple, nondestructive, and more objective and efficient than manual interpretation of spectrograms. Therefore, it is suitable to be used as a preliminary screening method for on-site law enforcement by regulators.

Key words：Near infrared spectroscopy; Modeling; Ivory identification

Received: 2022-04-16 Accepted: 2022-07-28

ZTFLH:

O433.4

Corresponding Authors: ZHANG Xiao-feng E-mail: breezeyh@hotmail.com

Cite this article:

WU Shan,ZHANG Ming-zhe,YU Hui-zhen, et al. Ivory Identification Based on Near Infrared Spectroscopy[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2023, 43(08): 2397-2406.

URL:

https://www.gpxygpfx.com/EN/10.3964/j.issn.1000-0593(2023)08-2397-10 OR https://www.gpxygpfx.com/EN/Y2023/V43/I08/2397

[1] Thouless C, Dublin H, Blanc J, et al. African Elephant Status Report 2016: An Update from the African Elephant Database (IUCN, 2016).
[2] Espinoza E O, Mann M J, Lemay J P, et al. Current Research in the Pleistocene, 1990, 7: 81.
[3] Espinoza E O, Mann M J, Goddard K W. Identification Guide for Ivory and Ivory Substitutes. WWF, Baltimore, 2nd ed, 1991.
[4] Wasser S K, Shedlock A M, Comstock K, et al. PNAS, 2004, 101(41): 14847.
[5] Wasser S K, Mailand C, Booth R, et al. PNAS, 2007, 104(10): 4228.
[6] Comstock K E, Ostrander E A, Wasser S K. Conservation Biology, 2003, 17(6): 1840.
[7] Wasser S K, Clark W J, Drori O, et al. Conservation Biology, 2008, 22(4): 1065.
[8] Lee J C, Hsieh H M, Huang L H, et al. International Journal of Legal Medicine, 2009, 123(2): 117.
[9] Suwanchatree N, Thanakiatkrai P, Linacre A, et al. International Journal of Legal Medicine, 2021, 135(1): 107.
[10] Wozney K M, Wilson P J. Forensic Science International, 2012, 219(1-3): 106.
[11] General Administration of Quality Supervision, Inspection and Quarantine of PRC; Standardization Administration of PRC(中华人民共和国国家质量监督检验检疫总局；中国国家标准化管理委员会). GB/T 16553—2017. Gems-Testing(珠宝玉石鉴定). Beijing: Standards Press of China(北京：中国标准出版社), 2017.
[12] WU Xiao, ZHANG Jun, LU Xian-hu(吴晓, 张钧, 鲁先虎). Journal of Gems and Gemmology(宝石和宝石学杂志）, 2013, 15(3): 50.
[13] XU Yan, HE Xue-mei(许彦, 何雪梅). Proceedings of China Gems & Jewelry Academic Conference(中国珠宝首饰学术交流会论文集), 2015: 153.
[14] Edwards H G, Farwell D W, Holder J M, et al. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 1997, 53A(13): 2403.
[15] Edwards H G, Jorge Villar S E, Nik Hassan N F, et al. Analytical & Bioanalytical Chemistry, 2005, 383(4): 713.
[16] Shimoyama M, Ninomiya T, Ozaki Y. Analyst, 2003, 128(7): 950.
[17] Shimoyama M, Morimoto S, Ozaki Y. Analyst, 2004, 129(6): 559.