CAPTAN AND THIOPHANATE-METHYL in Handrinse Thiophanate -M eth yl: C 12H 14N 4O 4S 2 Captan: C 9H 8Cl3NO 2S METHOD: 9202, Issue 1 Captan OSHA : N/A NIOSH: N/A ACGIH: N/A
MW: 342.40
CAS: 23564-0 5-8
300.59
RTECS: BA3675000
133-06-2
GW 5075000
EVALUATION: PARTIAL
Thiophanate-methyl N/A N/A N/A
9202
Issue 1: 15 March 2003
PROPERTIES: Thiophanate-methyl: Colorless prisms, mp 181.5182.5°C, soluble in acetone, methanol, chloroform, acetonitrile, insoluble in water. Captan: Odorless crystals, mp 178°C, soluble in chloroform, practically insoluble in H2 O.
NAMES & SYNONYMS: Thiophanate-Methyl: Topsin-M; [1,2-phenylenebis(iminocarbonothioyl)]bisdimethyl ester carbamic acid Captan: N-(trichloromethyl)thio-4-cyclohexene-1,2-dicarboximide; Captec SAMPLING SAMPLER:
SHIPMENT:
MEASUREMENT
POLYETHYLENE BAG 12" x 18", polyethylene bag containing 150 mL isopropanol
TECHNIQUE:
HPLC, UV detector
ANALYTE:
Captan and Thiophanate-methyl
transfer wash to 250-mL wide-mouth glass jars with PTFE-lined caps. Ship cold.
INJECTION VOLUME:
5 µL
SAMPLE STABILITY:
at least 28 days at 4° C
BLANKS:
2 to 10 field blanks per set
MOBILE PHASE:
A=2% n-propanol in water, 0.02 M TEAPO4 adjusted to pH 7.0 +/- 0.1 using phosphoric acid; B=2% n-propanol in acetonitrile. Gradient increasing from 20% B to 70% B over 20 min., decreasing to 20% B (2 min.) hold at 20% B (5 min.)
COLUMN:
Reversed Phase C-18, 4µ, 250 x 2.00 mm (or equivalent).
ACCURACY RANGE STUDIED:
Not studied
DETECTOR:
UV @ 200 nm
BIAS:
Not determined
CALIBRATION:
Solutions prepared in isopropanol
RANGE:
Table 1
OVERALL PRECISION ( Ö r T ):
Not determined
ACCURACY:
Not determined
ESTIMATED LOD: Table 1 PRECISION ( þ r ):
Table 1
APPLICABILITY: This method was developed for the analysis of captan and thiophanate-methyl in an isopropanol hand rinse solution from orchard workers. In addition, this method may also be used to analyze other fungicides and pesticides that may be present in the field as long as they are sufficiently separated from the analytes by the analytical conditions of the method and soluble in isopropanol. (Figure 1.) Outside of the investigation into possible analytical interferences, extensive research was not completed on other pesticides and fungicides. INTERFERENCES: The potential interferences include other organic compounds, in particular other agricultural chemicals that have the same retention time on a C18 column. Confirmation of the target fungicide can be checked by using an amino or phenyl LC column. Possible interferences include: ziram, myclobutanil, mancozeb, imidacloprid, and phosmet. OTHER METHODS: This method was developed in conjunction with NMAM 5606, Thiophanate-methyl in air and NMAM 9205, Captan and Thiophanate-methyl on dermal patches.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition CAP TAN and T HIOP HAN ATE -MET HYL: M ETH OD 9202, Issue 1, dated 1 5 Ma rch 2003 - Page 2 of 4 EQUIPMENT:
REAGENTS: 1. 2. 3. 4. 5.
Isop ropa nol, H PLC pesticide grade .* Aceton itrile, HPL C grade .* Triethylam ine (T EA).* Deionized water. Thiophanate-methyl* stock solution, 10 mg/m L. Prepare in acetonitrile. 6. Captan * stock s olution , 5 m g/m L. P repare in acetonitrile. 7. TEA-PO 4 Preservative. Dissolve 1.4 mL of TEA in 90 mL of deionized water in a 100 mL volumetric flask. Add phosphoric acid to lower pH to 7.0 +/- 0.1 as indicated by a calibrated pH m eter. B ring vo lum e to 100 m L with w ater. Keep tightly capped and refrigerated. Solution stable for 12 months. 8. Mobile phase A. Com bine 20 mL of npropanol and 2.8 mL triethylamine in a 1 L volumetric flask and bring to volume using deionized water. Adjust pH to 7.0 (+/- 0.1) with phosphoric acid using a pH m eter. Final concentrations: 2% n-propanol, 0.02 M TEAPO 4. Degas prior to use. 9. Mobile phase B. Transfer 20 mL of npropanol to a 1 L volumetric flask and adjust to volum e with a cetonitrile. Degas prior to use. 10. Ortho-p hos pho ric acid* >85 % by weight, ACS grade or better.
1. Sa m pler: 8" x 12" S ciencew are™ Re usable Heavyweight P olyethyle ne Bags, 4 m m wall thickness (B el-Art No. H1317 8-0812). 2. Co ntaine r: 250 m L sc rew-top c onta iner with PTF E liner. 3. High Performance Liquid Chromatograph (HPLC ) with UV detector. 4. Autosampler or injection valve capable of 5 µL injections. 5. An alytic al colum n: P henom enex® Synergi™ 4µ Hydro-RP 80A (250 x 2.00 mm ) or equ ivalent. 6. Vials, 2-mL with PTFE-lined caps. 7. Syringes, 50-:L, 1-mL, and 5-mL. 8. Volumetric flasks, 5-mL, 100-mL, and 1-L. 9. PTFE syringe filter, 4-mm , 0.45-µm pore. 10. pH m eter. 11. Graduated cylinders, 50-mL. 12. Pipettes, glass, disposable, 2-mL. 13. Bagge d refrigera nt.
- See SPECIAL PRECAUTIONS
SPECIAL PRECAUTIONS: Th iophana te-m ethyl: Avo id inhaling vap ors or du st; avo id sk in con tact. W ear glo ves and suitab le cloth ing when handling pure m ate rial. So lvents: Avoid sk in contac t and open flam e. Us e in a h ood . Pho sph oric acid: Av oid sk in con tact. C apta n: Use in h ood . Avoid con tact w ith sk in, eyes, and clothing an d inge stion o r inhalation. Eye protection sho uld be worn. SAMPLING: 1. Pour 150 mL of isopropanol into the polyethylene bag. 2. Insert hand into bag. W rap the top of the bag securely around the forearm, several inches above the w rist. NOTE: Allergies to alcohol are extremely rare. Before conducting the handwash, check to see if the person has ever had a reaction to alcohols, or is taking medications that could react with the alcohol. Some skin conditions, such as cuts, abrasions, and eczema can be irritated by contact with alcohols. If the person’s hand seems “dried-out” after the handwash, hand lotion can be applied. 3. Shake hand in alcohol with constant back and forth motion for 30 seconds. Rem ove hand from bag and dry with paper tow el. 4. Transfer solution to glass ja r, cap securely. 5. Lab el and pac k fo r shipm ent. 6. For field blank, add 150 mL isopropanol to a clean bag, shake for 30 seconds, then transfer the solve nt to a g lass jar for shipm ent.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition CAP TAN and T HIOP HAN ATE -MET HYL: M ETH OD 9202, Issue 1, dated 1 5 Ma rch 2003 - Page 3 of 4 SAMPLE PREPARATION: 7. Prepare analyst spike sam ples, solutions of isopropanol spiked with varying concentrations of the analytes of interest used for quality assurance, when field samples are received and store them together. Analyze with the field samples, blanks, and the liquid standards. Include unused 150 mL isopropanol wash of a polyethylene sampling bag as a media blank. 8. Rem ove a 1 m L aliquot from the sam ple container and filter with a 4m m 0.45 µm syringe filter.
CALIBRATION AND QUALITY CONTRO L: 9. Determine retention times for analytes using the column and chromatographic conditions as shown on pages 9202-1 & 9202-2. The approximate retention time of thiophanate-methyl is 11 minutes and cap tan is 1 9 m inutes . (See Figure 1.) 10. Calibrate daily with at least six working standards containing each of the two analytes and covering the analytical range for thiophanate-methyl and captan.
MEASUREMENT: 11. Set LC conditions according to manufacturer’s recomm endations. Set the wavelength for detection at 200 nm and the flow rate at 0.200 mL/m in. 12. Injec t a 5 µL sa m ple aliqu ot with a utos am pler. NOTE: If the peak area of a s am ple is greate r than the area of the highest standa rd, dilute with isopropanol and reanalyze. 13. Measure peak area of the analyte.
CALCULATIONS: 14. Perform a separate regression analysis of peak area vs. concentration of standard for each of the analytes. Determine the concentration, C (:g/mL), of the analyte in each sample from the calibration graph. 15. Ca lculate the m ass of ea ch analyte, M (:g), in the submitted sample volume, V(mL). Use a volume of 150 mL for the volume of the sample.
EVALUATION OF METHOD: This method was evaluated with a recovery study at room tem perature over the range of 8949-60270 µg /sa m ple for thiophanate -m eth yl and 13140-44070 µg/sa m ple for captan using spiked laboratory samples with respective average recoveries in the range of 91.1-100% and 93.7-95.3% . [1] A reco very study at 4°C was also performed o ver the range of 8940-60420 µg/sample for thiophanate-methyl and 13130-43930 µg /sa m ple for captan using sp iked laboratory sam ples with respective average recoveries in the range of 101111% and 102-105%. The storage study at room temperature was completed at 33990 µg/sample for thio phanate -m eth yl and 2620 0 µg/sam ple for captan with respective recovery averages of 102-107% and 102-127% over the 28 days of the study. The storage study at 4°C was completed at 34130 µg/sample for thio phanate -m eth yl, and 25520 µg/sample for captan with respective recovery averages of 110-121% and 102-112% over the 27 days of the stud y. Originally, carbendazim was included in the investigation since it is a breakdown product of thiophanatem eth yl. Atte m pts to quantita tively m easure carbendazim suffe red from rep roducibility problems prom pting carbendazim ’s rem oval from this m etho d as an analyte that can be quantified. This method may be used to qualitatively determ ine carbendazim . Under m eth od conditions, its approxim ate retention tim e is 6 minutes.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition CAP TAN and T HIOP HAN ATE -MET HYL: M ETH OD 9202, Issue 1, dated 1 5 Ma rch 2003 - Page 4 of 4 REFERENCES: [1] [2]
Andrews RN, Jaycox LB [2002]. Back-up Data Report for captan and thiophanate-methyl in handrinse, Cincinnati, OH: National Institute for Occupational Safety and Health, unpublished. NIOSH [1998]. Method 56 01. In: Cassinelli ME, O ’Connor PF , eds . NIO SH Manual of Analytical Methods (NM AM ), 4 th ed, 2 nd supplement. Cincinnati, OH: National Institute for Occupational Safety and Health, DHHS (NIOSH) Publ 98-119.
AUTHORS: Ronnee N. Andrews, NIOSH/ DART Larry B. Jaycox, Ph.D., NIOSH/ DART
Table 1. Analyte Captan Thiophanate -m eth yl
Range (:g/sample) 410 - 44070 198 - 60270
Estimated LOD (:g/sample) 123 60
Precision (þ r) 0.0326 0.0181
Figure 1. A typical chromatogram from the analysis of a hand rinse storage sample. The concentrations of the analytes shown here are: thiophanate-methyl - 226 µg/mL and captan 175 µg/mL.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition