Niobium carbide as permanent modifier for silicon determination in petrochemical products by emulsion-based sampling GF AAS

摘要: Abstract The sample preparation was carried out by emulsion-based sampling, using about 200 mg of samples (crude oil, diesel or gasoline), 125 μL hexane (only for crude oil) and 7.5 mL Triton X-100 (20% v v −1 ). mixture stirred manually few seconds, submitted to ultrasound bath 30 min, diluted 25 mL with high-purity water. combination NbC as permanent modifier avoid the formation thermally stable SiC 20 μg Pd co-injected chemical losses volatile silicon mandatory success proposed method. In these conditions, sensitivity increased around six times relative standard deviation decreased 10 times. After heating program optimization, pyrolysis atomization temperatures were 1300 °C 2600 °C, respectively. limit detection, quantification characteristic mass were, respectively, 2.6 μg L , 8.6 μg L 141 pg. lower than 1% 100 μg L Si. accuracy checked analysis oil-based Si standards found values are in accordance reference at 95% confidence level. Addition 30 μg L gasoline resulted recoveries ranging from 111%.