Maneb Dermal Patch (3600)
MANEB Dermal Patch C4 H6 N2 S4 Mn
MW: 265.2
METHOD: 3600, Issue 1
3600
CAS: 12427-38-2
RTECS: OP07000
EVALUATION: PARTIAL
OSHA : not applicable NIOSH: not applicable ACGIH: not applicable
PROPERTIES:
Issue 1: 15 March 2003
powder, yellow, wettable; sparingly soluble in water and organic solvents; vp not significant
NAMES & SYNONYMS: manganous ethylenebis(dithiocarbamic acid), Manzate; Dithane M-22
SAMPLING
MEASUREMENT
PATCH Dry NuGauze®, spun polyester gauze patch (see Figure 1)
TECHNIQUE:
HPLC, UV detection
ANALYTE:
ethylenebisdithiocarbamate anion
FLOW RATE:
not applicable
EXTRACTION:
VOL-MIN: -MAX:
not applicable not applicable
40 mL desorbing solution (1% Lcysteine, 3% Na 4 EDTA C2H2 O in water) in 50 to 65-mL wide-mouth bottles with Teflon®-lined screw caps
SHIPMENT:
desorb immediately in shipping bottles, pack in blue ice, cool to 4 °C, ship via overnight express
SAMPLER:
SAMPLE STABILITY:
at least 1 week at 4 °C
BLANKS:
2 to 10 field blanks per set ACCURACY
RANGE STUDIED:
not applicable
BIAS:
not determined
INJECTION VOLUME:
100 µL
MOBILE PHASE:
0.0675 M phosphate, 0.0525 M NaClO4 , pH 6.9, 1 g/L Na2 EDTA C2H2 O, 2 mL/min
COLUMN:
Dionex AS7 anion exchange column or equivalent, GS7 guard column
DETECTOR:
UV, 285 nm (8 max) or 254 nm
CALIBRATION:
solutions of Maneb in 1% L-cysteine, 3% Na2 EDTA
RANGE:
0.02 to 4 mg/sample [1]
OVERALL PRECISION ( Ö r T ):
not determined
ESTIMATED LOD:
0.02 mg/sample (0.5 µg/mL) [1]
ACCURACY:
not determined
PRECISION ( þ r ):
0.015 [1]
APPLICABILITY: This method determines Maneb collected on dry Nu Gauze® (spun polyester gauze) dermal patches attached to clothing on the arm(s), leg(s), or torso of agricultural workers. It is applicable to the determination of Zineb, Mancozeb, and Nabam since these all convert to the same analyte when dissolved in EDTA solution. INTERFERENCES: Not thoroughly investigated. No interferences have been found during method development.
OTHER METHODS: Maneb may also be determined by first methylating followed by HPLC analysis with a C18 column [2-5].
NIOSH Manual of Analytical Methods, Fourth Edition MA NEB , Derm al Patch: MET HO D 360 0, Issue 1, dated 15 M arch 200 3 - Page 2 o f 5 REAGENTS:
EQUIPMENT:
1. Maneb,* purity >90% 2. W ater, deionized 3. Mob ile Phas e, 0.0675 M phosph ate buffer, 0.0 525 M Na ClO 4, 1 g/L Na2EDTAC2H 2O: In a 1-L volumetric flask, dissolve 4.79 g dibasic sodium phosphate ; 4.5 9 g m onobasic potassium phosphate; 6.43 g sodium chlorate; 1 g ethylenediaminetetraacetic acid, disodium salt, dihydrate in 500 m L of deionized water. Bring to volume with deionized water. Adjust pH to 6.9. 4. L-cysteine, reagent grade. 5. Ethylenediaminetetraacetic acid, disodium salt, dihydrate (Na 2EDTAC2H 2O), reagent grade. 6. Sodium phosphate, dibasic, anhydrous (Na2HPO 4), reagent grade. 7. Potassium phosphate, monobasic, anhydrous (H 2PO 4), reagent grade. 8. So dium Ch lorate (NaC lO 3), reagent grade. 9. Ethylenediaminetetraacetic acid, tetrasodium salt, dihydrate (Na 4EDTAC2H 2O)* 10. Desorbing solution, 1% L-cysteine, 3% Na 4EDTA in water: In a 1-L volumetric flask, dissolve 10 g L-cystene and 30 g Na 4EDTAC2H 2O in 500 m L wa ter. Dilute to volume with deionized water. (The pH will be appro xim ately 8.6.*) 11. Calibration stock solution*, 1 mg/m L: Dissolve 10 mg M aneb in 10 mL desorbing solution.
1. Sam pler: Polyester gauze, Johnson & Joh nso n Nu G auze ® 10-cm x 10-cm (4" x 4"), 4-ply or equivalent. 2. Patch holders, aluminized cardboard (see Figure 1). 3. High performance liquid chromatograph (HPLC) with UV detector, 254 nm (or 285 nm if a variable-wa velength UV detec tor is available), and autosampler. Set chromatograph to conditions on page 1. 4. Columns: Dionex AS7 anion exchange colum n, AG 7 gu ard c olum n or e quiva lent. 5. Ultrasonic bath. 6. Forceps. 7. Bottles, wide-mouth, amber, 50- to 65-mL, with PTFE-lined screw caps. 8. Volumetric flasks, 10-mL, 100-mL, 1-L. 9. Graduated cylinder, 50-mL. 10. Vials, autosam pler. 11. Pipets, glass, various sizes. 12. Syringes, 100-µL with larg e bore needle ($19-gaug e).
- See SPECIAL PRECAUTIONS
SPECIAL PRECAUTIONS: Maneb has degradation products which are known to be carcinogenic, m utag enic, and teratogen ic [6-9]. Avoid con tact w ith Ma neb . W ear a ppro priate prote ctive equipm ent. Na 4EDTA is very alkaline. Avoid contact with skin or eyes of either the dry powder or aqueous solutions.
SAMPLING:
1. 2. 3. 4. 5.
NOTE: The sam pling procedure has not been thoroughly inve stig ate d. T his is a pro totyp e m eth od only. Place Nu Gauze® patches in the patch holders. Label each patch holder with name, date, body location, and tim e of a ttachm ent; then attach to clothing on the arm (s), leg(s), or torso of the hum an subje ct(s) at location noted on patch label. Label amber wide-mouth glass shipping bottles with the same information. After a 4- to 8-h our tim e period for the hum an subje ct(s) working in the field or with Maneb application equipment, remove the patch holders and record the time. Using forceps, remove the Nu Gauze® patches from the patch holders by folding the corners into the middle. Place patches in shipping bottles with as little disturbance of the collected Maneb as possible.
NIOSH Manual of Analytical Methods, Fourth Edition MA NEB , Derm al Patch: MET HO D 360 0, Issue 1, dated 15 M arch 200 3 - Page 3 o f 5 6.
7. 8. 9.
Prepare sufficient desorbin g s olu tion for all sam ple s a nd bla nks: 4 g L-cysteine and 12 g Na 4EDTAC2H 2O in 400 m L of de ionized water for every 10 sam ples (40 m L per sam ple). Prepare this solution in the field to prevent premature oxidation of the L-cysteine preservative. NOTE: The EDTA here m ust be the tetrasodium form , not the disodium form. See SPECIAL PRECAUTIONS. Add 40 m L of d eso rbing solution to each shipping bottle, cap, and shake well to wet the Nu Gauze® and dissolve the Maneb. Prepare 2 to 10 blank samples by adding 40 mL to clean Nu Gauze® patches in shipping bottles. Pack shipping bottles securely in blue ice or other means to keep at 4 / C, and ship via overnight express.
SAMPLE PREPARATION: NOT E: Desorption of samples is done on site. 10. On arrival at laboratory, store samples at 4 °C. 11. Ultrasonicate capped sample bottles for 5 to 10 minutes. 12. Transfer 1 to 2 mL of each desorbed sample solution, standards, and blanks to autosampler vials for analysis. Analyze within 24 hours.
CALIBRATION AND QUALITY CONTRO L: 13. Calibrate daily with at least six working standards over the range of 0.1 to 100 µg/mL. a. Pipet aliquots of ca libration s tock solution into 1 0-m L volum etric flas ks, and bring to volum e with desorbing solution. b. Include a calibration blank of unspiked working solution. c. Analyze together with field sam ples , field blanks, and laboratory control samples (steps15 through 17). d. Prepare a calibration graph (pe ak area vs. concentration, µg/m L). NOTE: To prepare media standards, prepare a slurry of Maneb in methanol, 1 mg/mL. Ultras onicate for approximately 2 minutes to pulverize and disperse the particles of Man eb. Shak e slurry periodically to ke ep the M ane b su spe nde d. Up to 20% ethylene glycol can be included to help keep the particles in suspension. W ithdraw a measured amount using a 100-µL syring e with a large bore ($ 19-gauge needle) and spike onto a dry Nu Gauze® patch within a 50- to 65-m L amber wide-m outh bottle. After drying, desorb the Maneb-spiked Nu Gauze® with 40 mL of desorbing solution and ultrasonicate. 14. Prepare laboratory contro l sam ples (LC S), in duplica te, with each sam ple se t. a. Spike Maneb in methanol onto 10-cm x 10-cm Nu Gauze® patches placed in 50- to 65-m L amber glass bottles in concentrations within the analytical range. b. Desorb with 40 mL of desorbing solution. c. Analyze along with field sam ples, standards, and blank s (steps 15 throug h 17).
MEASUREMENT: 15. Set liquid chromatograph to manufacturer’s recomm endations and conditions given on page 3600-1. 16. Transfer sa m ple aliquots to injection vials. Inject 100-µL aliquots man ually or with an autosam pler. Rinse and dry syringe after each injection. 17. Mea sure peak areas. If sample peak area exceeds the linear calibration range, dilute with aqueous 1% L-cysteine, 3% Na 4ED T AC2H 2O solution, reanalyze, and apply the appropriate dilution factor in the calculations.
NIOSH Manual of Analytical Methods, Fourth Edition MA NEB , Derm al Patch: MET HO D 360 0, Issue 1, dated 15 M arch 200 3 - Page 4 o f 5 CALCULATIONS: 18. From the calibration graph, read the concentration, C (µg/mL), of Maneb found in the sample. 19. Calculate the m ass, M, of M aneb in the sam ple (µg/sam ple).
CONFIRMATION: No confirm ation me thod has be en tested. Poss ible alternatives are ion-pairing chromatography with a C-18 colum n [5], or ana lysis of m ethylated de rivatives on a C-1 8 co lum n [3,4].
EVALUATION OF METHOD: This method has been evaluated in the laboratory only. No field samples have been analyzed to date. LOD/LOQ A s eries of m edia standard s (See N ote above un der s tep 13.d.) from 0.1 to 100 µg/mL were prepared in duplicate, analyzed, and fitted with a linear curve. The Limit of Detection (LO D), 0.02 m g/s am ple for a 40-mL desorbing volume, and Limit of Quantitation (LOQ), 0.066 mg/sample, were estimated using NIO SH SO P 01 8 [10]. PRECISION AND ACCURACY Twenty-four media standards were prepared, six at each of four levels: 3xLOQ, 10xLOQ, 30xLOQ, and 100xLOQ, as described above in Note under step 13.d. The m edia standards were desorbed with 40 m L of desorbing solution and analyzed. Levels 3xLOQ, 10xLOQ , and 100xLOQ were used to obtain a pooled relative standard de viation. One of the six sam ples at the 100xLO Q level was shown to be an outlier by Grubbs’ test and was not included in the calculations. Bias, Accuracy, and Overall Precision were not determined. The recoveries were all greater than 90% except for Level 3xLOQ, which was 88% [1]. STABILITY Stab ility studies were perform ed at 528 µg Maneb per dermal patch. At room temperature (24 / C), Maneb on dry Nu Gauze® patches was not stable, with less than 60% recovery on Day 2. At 4 / C, however, Maneb was stable on dry Nu Gauze® to at least Day 8. Maneb which was spiked onto Nu Gauze® and allowed to stand approximately two hours while the solvent dried and was then desorbed in a 1% L-cysteine, 3% Na 4EDTA solution, was stable to Day 22 with recoveries greater than 90% . At Da y 30 the reco very was 8 7% [1].
COM MEN TS: Most ethylene-bis-dithiocarbam ates (EBD C) containing divalent (or higher) metals (e.g., Maneb, Mancozeb, and Zineb) dissolve with difficulty in alm ost every so lvent. If the m etal ion is rem oved by co m plexation w ith E DT A (at hig h pH), the EBDC will dissolve but will begin to degrade rapidly, presumably by oxidation, to dis ulfides or o the r products. Adding an antio xidant su ch as L-c yste ine gre atly inhibits th is oxidative degradation. Ex cluding headspace air h as been show n to assist in re ducing oxidatio n; however, coo ling to 4 / C is one of the most important factors in sample preservation.
NIOSH Manual of Analytical Methods, Fourth Edition MA NEB , Derm al Patch: MET HO D 360 0, Issue 1, dated 15 M arch 200 3 - Page 5 o f 5 REFERENCES: [1] DataChem Laboratories [1995]. Backup Data Report for Maneb, dermal patch and hand wash. Unpublished report, DataChem Laboratories. , Salt Lake City, UT. [2] Bardarov V,. Zaikov C hr, Mitew a M [1989]. Application of H igh-Perform ance Liquid Chrom atog raph y with Sp ectrophoto m etric and Electrochemical Detection to the Analysis of Alkylenebis(dithiocarbamates) and their M etab olites. Journ al of C hrom atog raph y, 479: 97. [3] Gustafsson KH, Thompson R A [1981]. High-Pressure Liquid C hrom ato graphic Determination of Fungicidal Dithiocarbam ates . J. Agric. Fo od C hem . 29: 729. [4] Gustafsson, KH, Fahlgren CH [1983]. Determination of Dithiocarbamate Fungicides in Vegetable Foods tuffs by High -Perform anc e Liqu id Ch rom atog raph y. J. Agric. Foo d Chem . 31: 461. [5] Irth H, De Jong GJ, Frei RW , Brinkm an UATh [1990]. Determination of Dithiocarbamates in Residues by Liquid Chrom atog raph y with Selective Precolumn or Reaction-Detection Systems. Intern. J. Environ. Anal. Ch em . 39: 129. [6] Seiler J.F [1 974 ]. Mutat. Re s. 26: 189. [7] Vogeler K, D reze P , Rapp A , Steffan S H, U llem eyer H [1977]. Pflanzensch utz-N ach r. 30: 72. [8] Innes JRM, Valerio M, Ulland B, Pallotta AJ, Petruccelli L, Batres R R, Fa lk H L, G art JJ , Kle in M, Mitchel I, Peters J [1969]. J. N atl. Cance r Inst. 42: 1101. [9] Kh era, K S [1 973]. T etrato logy 7: 243. [10] NIOSH [1994]. NIOSH SO P 018, NIOSH/DPSE Quality Assurance Manual (December 1983). issued Jan. 24, 1984, Revised July 18, 1994.
METHOD WRITTEN BY: Paul C. Gillespie and John M. Reynolds, DataChem Laboratories, Salt Lake City, UT.
NIOSH Manual of Analytical Methods, Fourth Edition