Page:NIOSH Manual of Analytical Methods - 5602.pdf/1

This page needs to be proofread.

CHLORINATED AND ORGANONITROGEN HERBICIDES (AIR SAMPLING)

ANALYTES: Figure 1

Formula: Table 1

METHOD: 5602, Issue 1

CAS: Table 1

EVALUATION: PARTIAL

OSHA: Table 1 NIOSH: Table 1 ACGIH: Table 1

NAMES:

MW: Table 1

RTECS: Table 1

Issue 1: 15 January 1998

PROPERTIES: Table 1

Alachlor Cyanazine

Atrazine Metolachlor

2,4-D acid Simazine

SAMPLING SAMPLER:

5602

2,4-D, 2-ethylhexyl ester 2,4-D, 2-butoxyethyl ester MEASUREMENT

TECHNIQUE:

GAS CHROMATOGRAPHY/ ELECTRON CAPTURE DETECTOR (GC/ECD)

FLOW RATE: 0.2 to 1 L/min

ANALYTE:

Table 1

VOL-MIN: -MAX:

12 L 480 L

EXTRACTION:

2 mL 10% methanol/90% methyl t-butyl ether (with diazomethane), shaker 1 h

SHIPMENT:

routine

INJECTION VOLUME:

at least 30 days @ 5 C at least 10 days @ 25 C [1]

TEMPERATURE-INJECTION: -DETECTOR: -COLUMN:

SAMPLE STABILITY:

BLANKS:

FILTER/SOLID SORBENT TUBE (OVS tube: 11-mm quartz filter; XAD-2)

2 µL

2 to 10 field blanks per set

270 C 300 C 90 C, 1 min; 35 C/min to 160 C; 3 C/min to 230 C; hold 9 min.

CARRIER GAS:

He at 1 mL/min

COLUMN:

capillary, fused silica, 30 m X 0.25-mm ID, 0.25-µm film, 50% phenyl, 50% methyl silicone, DB-17 or equivalent. See Table 2.

CALIBRATION:

standard solutions of herbicides in methanol/ methyl t-butyl ether (10:90)

RANGE:

Table 3

ACCURACY

RANGE STUDIED:

Table 3

ACCURACY:

Table 3

BIAS:

Table 3

OVERALL PRECISION (

rT):

Table 3

ESTIMATED LOD: Table 3 PRECISION ( r):

Table 3

APPLICABILITY: The working ranges, listed in Table 3, cover ranges from the LOQ to approximately 30 X LOQ. This method may be applicable to the determination of many other thermally stable organonitrogen, aryl and alkyl acidic, and phenolic pesticides after evaluation. Determination of cyanazine is semiquantitative using this method. INTERFERENCES: Because of the great sensitivity of the ECD, there are many potential interferences. Those observed are plasticizers (e.g., dibutyl phthalate), methylated fatty acids (negative response), phenols, antioxidants, and other additives (e.g., BHT) , any volatile or semivolatile halogenated or nitrated organic, organophosphorous compounds, and other pesticides. Agricultural spray additives, such as solvents, emulsifiers, wetting agents, breakdown products, and fertilizers (e.g., fatty acids and urea), can present serious interferences. Second-column confirmation is very desirable (See Table 3). The background levels of different lots of OVS tubes vary widely and may interfere at the lower levels. OTHER METHODS: This method replaces previously related pesticide methods. Alternate methods for the determination of 2,4-D in air are S279 [2] and 5001 [3]. The OVS tube is similar in concept to the device of Hill and Arnold [4], but offers greater convenience and lower flow resistance. Other methods allowing simultaneous determination of organonitrogen and acid compounds and their esters are unknown.

NIOSH Manual of Analytical Methods, Fourth Edition