Page:NIOSH Manual of Analytical Methods - 5527.pdf/3

 TR IPHEN YL TIN CH LOR IDE: ME TH OD 5527, Issue 1, dated 1 5 Ma rch 2003 - Page 3 of 5 with desorbing solution. b. Analyze sam ples and blank s (steps 10 an d 11). c. Prepare a calibration graph (pe ak area vs µg Sn ). 8. One day before analyzing samples, prepare three spiked media blanks. Desorb (steps 3 through 6) and analyze with standards and blanks. 9. Analyze three quality control blind spikes and three analyst spikes to check calibration graph.

MEASUREMENT: 10. Set ICP for analysis of organic compounds according to manufacturer’s specifications. 11. Operate HPLC under the following conditions: a. C 18 column b. Flush column with approximately 30 mL of mobile phase before connecting to ICP c. Mobile phase flow rate: 1 m L/m in d. After ICP is ready for analysis, connec t effluent from HP LC to ICP spra y cham ber. 12. Injec t standard s, sa m ples, and blank s on to HPLC colum n an d rec ord c hrom atog ram s.

CALCULATIONS: 13. Analyze chrom atog ram s us ing a c onvenient HPLC software p rogram. 14. Cons truct a calibration graph (pe ak area versus µg of tin). 15. From calibration graph determine the mass in µg of tin for each sample (W ) and for the average m edia blank (B). Calculate the conc entration, C, of tin in the volume o f air samp led, V (L):

NOT E: µg/L  m g/m 3

EVALU ATION OF M ETH OD : This method was developed in response to an increased use of organotin compounds in the workplace and to test the applicability of the hyphenated technique of HPLC-ICP-AES for their analysis. Triphenyl tin chloride, the compound of this method, is a pesticide and an antifouling agent for paints. ICP instrum ents a re typically set up fo r the analysis of in organic m eta l com pounds. W hen one is used as a detector for organo-metal compounds in the effluent of an HPLC instrument, certain modifications of the operating con ditions of the ICP m ust be co nsidered. Its torch and spray chamber m ust be suited to the analysis of organic com pounds and gas flow rates are different for analysis of solution s contain ing org anic compounds. Such information can be obta ined from the m anufacturer of a specific ICP instrument. In addition, oxygen gas is introduced into the plasma to prevent the formation of carbon deposits. This method was evaluated for limit of detection (LOD), linear range, and sample stability [1]. An instrumental LOD of 3 µg as tin per sample was determined. This corresponds to a Lim it of Quantita tion that is approximately 0.1 x the Permissible Exposure Limit (PEL). Calibration standards showed the method to be linear to an upper limit of approximately 240 µg per sample which is equivalent to 2.4 times the PEL. Samples with higher concentrations were not tested. The method was further evaluated by a recovery study using spiked lab sam ples on polyvinyl chloride filters that contained triphenyl tin chloride at four levels in the range of 9.5 to 190 µg as tin per sam ple. This range is from approxim ate ly 0.1 to 2 x the PEL. At each level six filters were analyzed. Recoveries ranged from 97% to 100% with an average RSD of 0.034. Filters were also spiked at 95 µg/sample and stored at room temperature for 7, 14, and 28 days. Recoveries ranged from 96% to103% with an average RSD of 0.032. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition