title: A line-scan hyperspectral system for high-throughput Raman chemical imaging.
abstract: A line-scan hyperspectral system was developed to enable Raman chemical imaging for large sample areas. A custom-designed 785 nm line laser based on a scanning mirror serves as an excitation source. A 45° dichroic beam splitter reflects the laser light to form a 24 cm × 1 mm excitation line normally incident on the sample surface. Raman signals along the laser line are collected by a detection module consisting of a dispersive imaging spectrograph and a CCD camera. A hypercube is accumulated line by line as a motorized table moves the samples transversely through the laser line. The system covers a Raman shift range of -648.7 to 2889.0 cm(-1) and a 23 cm wide area. An example application for authenticating milk powder is presented to demonstrate the system performance. In 4 min the system acquired a 512 × 110 × 1024 hypercube (56  320 spectra) from four, 47 mm diameter Petri dishes containing four powder samples. Chemical images were created for detecting two adulterants (melamine and dicyandiamide) that had been mixed into the milk powder.
authors.affiliation: Environmental Microbial and Food Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, 10300 Baltimore Ave., Beltsville, MD 20705 USA.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Qin
authors.affiliation: Environmental Microbial and Food Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, 10300 Baltimore Ave., Beltsville, MD 20705 USA.
authors.forename: Kuanglin
authors.initials: K
authors.lastname: Chao
authors.affiliation: Environmental Microbial and Food Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, 10300 Baltimore Ave., Beltsville, MD 20705 USA.
authors.forename: Moon S
authors.initials: MS
authors.lastname: Kim
mesh_terms: D000818:Animals; D003611:Dairy Products / Q000032:analysis*; D004867:Equipment Design; D005506:Food Contamination / Q000032:analysis*; D006146:Guanidines / Q000032:analysis; D057166:High-Throughput Screening Assays / Q000295:instrumentation* / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D008892:Milk / Q000737:chemistry; D011208:Powders; D013048:Specimen Handling / Q000295:instrumentation; D013059:Spectrum Analysis, Raman / Q000295:instrumentation* / Q000379:methods; D014227:Triazines / Q000032:analysis
chemical_list: D006146:Guanidines; D011208:Powders; D014227:Triazines; C004711:dicyandiamido; C011907:melamine