Page:NIOSH Manual of Analytical Methods - 5526.pdf/2

 METHYLTIN CHLORIDES: METHOD 5526, Issue 1, dated 15 March 2003 - Page 2 of 5 EQUIPMENT:

REAGENTS: 1. 2. 3. 4. 5. 6. 7. 8. 9.

Acetic Acid, 99 +% .* Aceton itrile, HPL C grade .* Dieth yl Ether, 99+% .* Hex ane, H PLC grade *. Methyltin Trichloride, 97%. Dimethyltin Dichloride, 97%. Trimethyltin Chloride. 1% acetic acid in acetonitrile solution, (v/v). Sodium tetraethyl borate.* NOTE: Pu rity of sodium tetraethyl borate is critical. It should appear as a fine white powder. Clumping or yellowing indicates that the compound m ust be replaced. 10. Sodium Acetate - Acetic Acid Buffer, pH 4.0 ± 0.2. Com mercially available from Fisher Scientific. 11. Derivatizing Solution: Prepare a solution containing 1% (w/v) of sodium tetraethylborate in diethyl ether. Prepare the solution fresh daily, preferably im m ediate ly before use. 12. Calibration Stock Solution: Prepare a stock calibra tion so lution by accurate ly weighing (to ± 0.1 m g) about 0.1 g each of m eth yltin trichloride, dimethyltin dichloride and trim eth yltin chloride into a 50 m l volum etric flask. Dilute to volum e with 1% acetic acid in acetonitrile. The stock solution contains about 1000 :g/m l (as tin) of eac h co m pon ent. Stored in a freezer, this solution remains stable for several weeks.

1.

Sampler: OSHA Versatile Sampler (OVS tube ), 13-m m OD inlet, 6-m m OD outlet. Front section contains 270 mg 20/60 mesh XAD -2 sorbent held in place by an 11-m m diameter glass fiber filter and Teflon® ring, separated from the back section of 140 mg XAD-2 sorbent by a short plug of polyureth ane fo am. The back sectio n is held in place with a plug o f polyure than e foa m. The tube is available comm ercially from SKC, Inc. (c at. #226-3 0-16 ) and Sup elco, Inc. (cat. 2. Personal sa m pling pum p: 0.1 to 1 L/m in with flexible and inert connecting tubing. 3. Gas chromatograph equipped with a cool oncolum n injec tion po rt, autom ated injecto r, DB-5 capillary c olum n, flam e-photo m etric detector (FPD) with a tin-specific filter (610 nm), and data collection system or equivalent (page 552 6-1). 4. Balance capable of weighing to ±0.1 mg. 5. Mec hanical shake r. 6. Vials, 10-mL, with PTFE-lined screwcaps. 7. Transfer pipettes or eyedroppers. 8. GC autosampler vials with PTFE-lined caps. 9. 5-mL,10-mL and 50-mL volumetric flasks. 10. Pipettes capable of accurately delivering 10
 * 1) OR BO -49P).
 * L and 1.0 and 2.0 mL.

11. Refrigerant packs for shipping.


 * See SPECIAL PRECAUTIONS

SPECIAL PRECAUTIONS: Concentrated acetic acid is corrosive and an irritant. Sodium Tetraethylborate is sensitive to air and m oisture. This chem ical should be stored and h andled unde r a nitrogen a tm osp here. Ace tonitrile, diethyl ether, and h exa ne a re all flam m able. W ear a ppro priate protective clothing and work with these compounds in a well ventilated hood. SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Uncap the sorbent tube immed iately before sampling and connect to a personal sampling pum p with flexible tubing. 3. Sa m ple at an accurately k nown flow rate betw een 0.25 L/m in fo r full shift sam pling and 1 L/m in for 15 minutes samples (STEL) for a maximum of 75 L. 4. Cap the samplers. Pack securely for shipment with cold refrigerant packs. NOTE: After receipt at the laboratory, samples should be stored at 4°C and analyze within 14 days of collection.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition