Applications of laser ablation - inductively coupled plasma - mass spectrometry (LA-ICP-MS) were investigated. Chapter 1 is a general introduction. Chapter 2 describes the use of LA-ICP-MS to determine rare earth elements (REE) in garnets. The chondrite normalized REE plots of garnets show variations based on how the garnets were formed. Garnets also showed positive or negative Eu anomalies. The plots and data showed what garnets could be used for indication of ore bodies.;Chapter 3 was a study of the possible use of caulk and automotive filler for forensics purposes. Many samples of each material were analyzed by LA-ICP-MS. The 186 masses monitored during ablation were used in principal components analysis (PCA). PCA scores plots were produced containing samples from different manufacturers and lot numbers. The automotive filler samples were distinguishable by both manufacturer and lot number. The caulk samples were only distinguishable by manufacturer.;New methods for the ablation of individual particle ensembles were investigated in Chapter 4. Gelatin was used as a substrate to capture and hold particles for analysis by LA-ICP-MS. The ablation shockwave was absorbed by the gelatin, and no other particles were disturbed. Analysis of uranium oxides was performed with a precision of up to 2.9%. The particle ensembles on filter paper were fixed there for ablation by coating the paper with a collodion solution. An attempt to improve the ablation characteristics of these methods was also attempted. Vanillic acid was added to the collodion and sprayed onto the particles fixed on gelatin. The results of the vanillic acid addition are discussed. Chapter 5 is a general conclusion.