4-(2,4-Dichlorophenoxy)butyric acid

249.09

249.09

202-366-9

SL314DW868

70337

3077|2588

DTXSID7024035

White crystals|White to light brown crystals

2918990021

46.53000

3.23700

Off-white Amorphous Powder

1.369g/cm3

118-120 °C

324.35 °C

1.552

53mg/L(room temperature)

0-6°C

3.5X10-6 mm Hg at 25 deg (est)

Oral-Rat  LD50: 700 mg/kg

Combustion produces toxic chloride gas

Slightly phenolic

Henry's Law constant estimated to be 2.29X10-9 atm-cu m/mole at 25 °C.

pKa= 4.95 at 25 °C

Koc of 4-(2,4-dichlorophenoxy)butyric acid has been experimentally measured to be 370 at pH 7.9.

No rapid reaction with air. No rapid reaction with water.

Acids, Carboxylic

2,4-DB is an organic acid. Neutralizes bases in exothermic reactions. Forms water soluble metal and amine salts. Hard water precipitates the calcium and magnesium salts from aqueous solutions of such salts.

The acid is slightly corrosive to iron.

III

6.1(b)

UN 3077 9/PG 3

2

22-51/53

25-29-46-61

ES9100000

Xn,N

The warehouse is ventilated, low temperature and dry; stored and transported separately from food materials

P273

H302-H411

Group I Containers: Combustible containers from organic or metallo-organic pesticides (except organic mercury, lead, cadmium, or arsenic compounds) should be disposed of in pesticide incinerators or in specified landfill sites. /Organic or metallo-organic pesticides/|Group II Containers: Non-combustible containers from organic or metallo-organic pesticides (except organic mercury, lead, cadmium, or arsenic compounds) must first be triple-rinsed. Containers that are in good condition may be returned to the manufacturer or formulator of the pesticide product, or to a drum reconditioner for reuse with the same type of pesticide product, if such reuse is legal under Department of Transportation regulations (eg 49 CFR 173.28). Containers that are not to be reused should be punctured ... and transported to a scrap metal facility for recycling, disposal or burial in a designated landfill. /Organic or metallo-organic pesticides/

In an altered process to prepare 2,4-dichlorophenoxybutyric acid, the lactone /butyrolactone/ was added to the other components, and soon after, the reaction temperature reached 165 °C, higher than the usual 160 °C. Application of cooling failed to check the thermal runaway, and soon after reaching 180 °C the vessel began to fail and an explosion and fire occurred.

WHO; Environ Health Criteria: Phenoxyherbicides (1984).|Nat'l Research Council Canada; Phenoxy herbicides NRCC No. 16075 (1978).

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Some may burn but none ignite readily. Containers may explode when heated. Some may be transported hot. For UN3508, be aware of possible short circuiting as this product is transported in a charged state. (ERG, 2016)

|Warning|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P273, P301+P312, P330, P391, and P501|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|Aggregated GHS information provided by 199 companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: SMALL FIRE: Dry chemical, CO2, water spray or regular foam. LARGE FIRE: Water spray, fog or regular foam. Do not scatter spilled material with high-pressure water streams. Move containers from fire area if you can do it without risk. Dike fire-control water for later disposal. FIRE INVOLVING TANKS: Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent dust cloud. Avoid inhalation of asbestos dust. SMALL DRY SPILL: With clean shovel, place material into clean, dry container and cover loosely; move containers from spill area. SMALL SPILL: Pick up with sand or other non-combustible absorbent material and place into containers for later disposal. LARGE SPILL: Dike far ahead of liquid spill for later disposal. Cover powder spill with plastic sheet or tarp to minimize spreading. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. (ERG, 2016)

Avoid continuous exposure, even to small amounts.

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./|The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.|The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

2,4-DB is irritating to skin and mucous membranes.

moderately toxic

LD50 Rat oral 700 mg/kg|LD50 Mouse oral 400 mg/kg

4-(2,4-Dichlorophenoxy)butyric acid's use as a herbicide to control broadleaf weeds(1) releases the compound directly to the terrestrial environment(SRC). Selected esters of 4-(2,4-dichlorophenoxy)butyric acid are also used as herbicides(1); these esters hydrolyze in moist soil to yield 4-(2,4-dichlorophenoxy)butyric acid(2).

TERRESTRIAL FATE: Microbial degradation is the major decomposition mechanism for phenoxyalkanoic acids (such as 4-(2,4-dichlorophenoxy)butyric acid) in soil(1-2). The microbial degradation occurs through a beta-oxidation mechanism to form (2,4-dichlorophenoxy)acetic acid (2,4-D)(2-3). In moist soils at 21 °C, the beta-oxidation half-life is about 3-4 days(3). In laboratory persistence studies using three different soil types (heavy clay, clay loam, sandy loam), half-lives of less than 7 days were observed(4). At normal herbicide application rates, 4-(2,4-dichlorophenoxy)butyric acid has a residual activity of about 6 weeks in soil(2). An experimentally measured Koc value of 370(5) suggests that 4-(2,4-dichlorophenoxy)butyric acid will be moderately mobile in soil and could therefore leach(SRC).|AQUATIC FATE: Microbial degradation is probably the major degradation process in the aquatic environment since it is the major decomposition mechanism for phenoxyalkanoic acids (such as 4-(2,4-dichlorophenoxy)butyric acid) in soil(1-2). The results of one aqueous stability study have also suggested that microbial degradation is important(3). Since 4-(2,4-dichlorophenoxy)butyric acid absorbs UV light in the environmental spectra(1), exposure to sunlight may contribute to its environmental decomposition; however, the relative importance of photolysis is unknown(SRC). Aquatic hydrolysis, bioconcentration and adsorption to sediment are not expected to be important fate processes(SRC).|ATMOSPHERIC FATE: Based upon an estimated vapor pressure of 3.5X10-6 mm Hg at 25 °C(1), 4-(2,4-dichlorophenoxy)butyric acid can exist in both the vapor and particulate-phases in the ambient atmosphere(2,SRC). It will degrade rapidly in the vapor-phase by reaction with photochemically produced hydroxyl radicals with an estimated half-life of 27 hr(3,SRC). Physical removal of particulates by dry deposition (settling) and wet deposition (rainfall, washout) will also occur(SRC).

Phenoxy herbicides have an ultraviolet absorption maximum in water in the 280-290 nm range, they ... can absorb radiation and be photochemically degraded. /Phenoxy herbicides/|Since phenoxyalkanoic acids have ultraviolet absorption maxima in water between 280 and 290 nm, there is a potential for direct photolysis in sunlight(1); photolysis rate data specific to 4-(2,4-dichlorophenoxy)butyric acid are not available; however, the similar compound (2,4-dichlorophenoxy)acetic acid has been shown to photolyze in sunlight with half-lives ranging from several days to several weeks(2). The rate constant for the vapor-phase reaction of 4-(2,4-dichlorophenoxy)butyric acid with photochemically produced hydroxyl radicals has been estimated to be 1.42X10-11 cu cm/molecule-sec at 25 °C which corresponds to an atmospheric half-life of about 27 hrs at an atmospheric concn of 5X10+5 hydroxyl radicals per cu cm(3,SRC). 4-(2,4-Dichlorophenoxy)butyric acid does not contain any functional groups that are susceptible to aqueous hydrolysis in the environment(4,SRC); distilled water solutions of 4-(2,4-dichlorophenoxy)butyric acid showed no degradation during 50 day stability experiments(5).

Based upon a measured log Kow of 3.53(1) and a water solubility of 46 mg/l at 25 °C(2), the BCF for 4-(2,4-dichlorophenoxy)butyric acid can be estimated to be about 280 and 70, respectively, from linear regression-derived equations(3,SRC). These BCF values suggest that bioconcentration in aquatic organisms is not important(SRC).

4-(2,4-Dichlorophenoxy)butyric acid has a pKa of 4.95 at 25 °C(1); therefore, it will exist predominantly in the dissociated form at pHs of 5 or higher(SRC). The Koc of dissociated species can not be estimated accurately; however, the Koc of 4-(2,4-dichlorophenoxy)butyric acid has been experimentally measured to be 370 at pH 7.9(1). This Koc value suggests a classification of medium soil mobility(2,SRC).

The Henry's Law constant for 4-(2,4-dichlorophenoxy)butyric acid can be estimated to be 2.29X10-9 atm-cu m/mole at 25 °C using a structure estimation method(1,SRC). This value of Henry's Law constant suggests that 4-(2,4-dichlorophenoxy)butyric acid is essentially nonvolatile from water(2).

SURFACE WATER: A total of 454 water samples were collected at the river mouths of the Grand, Saugeen and Thames Rivers in Ontario, Canada between Jan 1981 and Dec 1985(1) and analyzed for pesticides(1); 4-(2,4-dichlorophenoxy)butyric acid was detected in 3 samples from the Thames River at a mean concn of 2.7 ug/l(1).|GROUNDWATER: Monitoring of several hundred farm wells for pesticides used by farmers in agricultural regions of Ontario, Canada between 1979 and 1987 did not detect any 4-(2,4-dichlorophenoxy)butyric acid at a detection limit of 0.1 ug/l(1-3).

As part of the Food and Drug Administration's Market Basket Survey of ready-to-eat foods, 4-(2,4-dichlorophenoxy)butyric acid was detected at a level of 0.025 ppm in a dairy product collected from a Los Angeles grocery store(1); 4-(2,4-dichlorophenoxy)butyric acid was classified as a pesticide that was infrequently found in American foods(1). In a compilation of three federal monitoring programs for fiscal years 1970-1976 (FDA's Market Basket Survey, FDA's Monitoring Program for 33,000 domestic and 18,000 raw agricultural commodities, and USDA's National Residue Program), 4-(2,4-dichlorophenoxy)butyric acid was detected in only one bean sample and in only one vine and ear vegetable sample(2).

As part of the Food and Drug Administration's Market Basket Survey of ready-to-eat foods, 4-(2,4-dichlorophenoxy)butyric acid was detected at a level of 0.025 ppm in a dairy product collected from a Los Angeles grocery store(1).

Exposure to chlorophenoxy herbicides (such as 4-(2,4-dichlorophenoxy)butyric acid) may occur through inhalation, skin contact or ingestion(1); in most cases, the predominant route of occupational exposure has been by the absorption of spills or aerosol droplets through the skin(1).|... Occupational exposure to chlorophenoxy herbicides ... is known to have occurred during their production, formulation, application & disposal. /Chlorophenoxy herbicides/

Urine samples from 197 Arkansas were analyzed for 4-(2,4-dichlorophenoxy)butyric acid(1); it was detected (detection limit of 1 ppb) in only one sample (concn not reported)(1).

ESTERS NORMALLY EXHIBIT GREATER HERBICIDAL ACTIVITY THAN PARENT ACIDS, BECAUSE OF IMPROVED ABSORPTION BY TARGET PLANTS. /PHENOXYALKANOIC ACIDS/|The chlorophenoxy compounds are absorbed across the gut wall, lung, and skin. They are not significantly fat storable. Excretion occurs almost entirely by way of the urine. /Chlorophenoxy herbicides/

Converted by beta-oxidation to 2,4-D in animals and susceptible plants.|Soybean (Glycine max (L.) Merr. var. Lee) and cocklebur (Xanthium sp.) contained beta-oxidase enzymes that were capable of degrading 2,4-DB to 2,4-D. An intermediate metabolite was identified as 4-(2,4-dichlorophenoxy) crotonic acid. Another metabolite pathway was indicated by synthesis of 10-(2,4-dichlorophenoxy)decanoic acid. 2,4-DB(14)C was applied to curly dock (Rumex crispus L.) and buckhorn plantain (Plantago lanceolata L.). The main pathway of metabolism was beta-oxidation and 2,4-D was identified as the major metabolite. Other unidentified metabolites appeared bound to polar lipids. 2,4-DB methyl ester was administered in soybean oil to a guinea pig. Urine was collected and GLC-MS analysis indicated the presence of the methyl ester of 2,4-D after treatment of the extract with diazomethane. Phytophthora megasprma var. sojae and cell suspensions of white clover (Trifolium repens) were not able to metabolize 2,4-D but did degrade 2,4-DB by a path not including beta- oxidation. Over a 21-day period, the fungus Phytophthora megasperma degraded about 45% of the 2,4-DB present. Since no 2,4-D was found in the nutrient medium, or fungus myceluim, it was concluded that degradation did not include beta-oxidation of 2,4-DB. The fungus did degrade 2,4-D. In Saskatchewan soils, hydrolysis of n-butyl 2,4-DB ester was rapid but products were not identified.|A typical beta-oxidation product (2,4-D) is observed via phenoxybutenoic acid in 2,4-DB metabolism by plants. The decanoic acid derivative of 2,4-dichlorophenol is an interesting metabolite.

In plants, these chemicals /chlorophenoxy compounds/ mimic the action of auxins, hormones chemically related to indoleacetic acid that stimulate growth. No hormonal activity is observed in mammals and other species, and beyond target organ toxicity that can be associated with the pharmacokinetics, biotransformation, and/or elimination of these chemicals, their mechanism(s) of toxic action are poorly understood. /Chlorophenoxy compounds/|A growth regulator herbicide similar in action to 2,4-D but more selective since its activity is dependent on beta-oxidation to 2,4-D within the plant.

May contain dioxins as contaminants ... . /Chlorophenoxy compounds; from table/

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Inhalation of material may be harmful. Contact may cause burns to skin and eyes. Inhalation of Asbestos dust may have a damaging effect on the lungs. Fire may produce irritating, corrosive and/or toxic gases. Some liquids produce vapors that may cause dizziness or suffocation. Runoff from fire control may cause pollution. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. (ERG, 2016)

Bath and shampoo with soap and water to remove chemicals from skin and hair. Obtain medical treatment if irritation persists. Individuals with chronic skin disease or known sensitivity to these herbicides should either avoid using them or take strict precautions to avoid contact (respirator, gloves, etc.). Flush contaminating chemicals from eyes with copious amounts of clean water for 10-15 minutes. If irritation persists, obtain medical treatment. /Chlorophenoxy cmpd/|If any symptoms of illness occur during or following inhalation of spray, remove victim from contact with the material for at least 2-3 days. Allow subsequent contact with chlorophenoxy compounds only if effective respiratory protection is practiced. /Chlorophenoxy cmpd/|If substantial amounts of chlorophenoxy compounds have been ingested, spontaneous emesis may occur. If vigorous emesis has not occurred, measures should be taken to empty the stomach and limit GI absorption by gastric intubation, aspiration, and lavage, following placement of a cuffed endotracheal tube. Repeated administration of charcoal at half or more the original dosage every 2-4 hr may be beneficial. If gastric aspiration and lavage is not performed due to delay in treatment, and if the patient is fully alert, administer charcoal and laxative orally. Administer intravenous fluids to accelerate excretion of the chlorophenoxy compound, and to limit concentration of the toxicant in the kidney. A urine flow of 4-6 ml/min is desirable. Iv saline/dextrose has sufficed to rescue comatose patients who drank 2,4-D and mecoprop several hours before hospital admission. Caution: Monitor urine protein and cells, BUN, serum creatinine, serum electrolytes, and fluid intake/output carefully to insure that renal function remains unimpaired and that fluid overload dose not occur. Forced alkaline diuresis has been used successfully in management of suicidal ingestions of chlorophenoxy compounds. Alkalinizing the urine by including sodium bicarbonate (44-88 mEq/l) in the iv solution apparently accelerates excretion of 2,4-D dramatically and mecoprop excretion substantially. Urine pH should be maintained in the 7.5-8.8 range. Include potassium chloride as needed to offset increased potassium losses: add 20-40 mEq of potassium chloride to each liter of iv solution. Monitor serum electrolytes carefully. There may possibly be some hazard to the kidneys when urine concentrations of toxicant are very high, so integrity of renal function and fluid balance should be monitored carefully as the chlorophenoxy compound is excreted. Hemodialysis is not likely to be of significant benefit in poisonings by chlorophenoxy compounds because of the extensive protein binding of these chemicals. Follow-up clinical examinations should include electromyographic and nerve conduction studies to detect any neuropathic changes and neuromuscular junction defects. /Chlorophenoxy cmpd/

The risk of soft tissue sarcoma following possible exposure to phenoxy acid herbicides was studied in 354,620 Swedish men, who were employed in agriculture or forestry according to a national census in 1960. This cohort was further divided into six subcohorts, on assumed exposure to phenoxy acid herbicides. The reference cohort encompassed 1,725,845 Swedish men employed in other industries. All persons were followed up in the cancer environment register during the period 1961-79. A total of 331 cases of soft tissue sarcomas was observed in the study cohort and there were 1,508 cases in the reference group (relative risk 0.9; 95% confidence interval, 0.8-1.0). No subcohort of agricultural or forestry workers showed any significantly increased relative risk, nor was there any significant difference in relative risk between the subcohorts. Despite the greatly increased use of phenoxy acid herbicides from 1947 to 1970, no time related increase in the relative risk of soft tissue sarcoma was found in the total cohort or in any of the subcohorts. /Phenoxy acid herbicides/|In 1977, a number of patients with soft tissue sarcomas and previous exposure to phenoxyacetic acids were described. Following from these observations, a matched case control study was made. The results showed that exposure to phenoxyacetic acids or chlorophenols gave an approximately six-fold increase in the risk factor for this type of tumor. It was not possible to determine, however, whether the carcinogenic effect was exerted by these compounds or by impurities such as chlorinated dibenzodioxins and dibenzofurans that in almost all cases were part of the commercial preparations. /Phenoxyacetic acids and chlorophenols/|A number of men with malignant lymphoma of the histiocytic type and previous exposure to phenoxy acids or chlorophenols were observed and reported in 1979. A matched case-control study has therefore been performed with cases of malignant lymphoma (Hodgkin's disease and non-Hodgkin's lymphoma). This included 169 cases and 338 controls. The results indicate that exposure to phenoxy acids, chlorophenols, and organic solvents may be a causative factor for malignant lymphoma. Combined exposure to these chemicals seemed to increase the risk. Exposure to various other agents was not obviously different in cases and in controls. /Phenoxy acids and chlorophenols/|A previous case-control study which used the occupational information available on the New Zealand Cancer Registry found that agricultural workers were at increased risk of developing non-Hodgkin's lymphoma. The findings are now presented for the second phase of the study which entailed interviewing 83 cases of non-Hodgkin's lymphoma registered under code 202 of the International Classification of Diseases together with 168 controls with other types of cancer and 228 general population controls. The findings for the two control groups were similar, and there were no significant differences between cases and controls regarding potential exposure to phenoxyherbicides (odds ratio= 1.4, 90% confidence limits 0.7-2.5, p= 0.26) or chlorophenols (odds ratio= 1.3, 90% confidence limits 0.6-2.7, p= 0.39). The odds ratio for fencing work, necessitating exposure to several potential risk factors including arsenic and sodium pentachlorophenate was 2.0 (90% confidence limits 1.3-3.0, p= 0.01). The odds ratio for employment in a meat works, necessitating potential exposure to 2,4,6-trichlorophenol and zoonotic viruses, was 1.8 (90% confidence limits 1.1-3.1, p= 0.04). There was a significant statistical interaction between the risks associated with these two activities, the odds ratio for involvement in both activities compared with involvement in neither being 5.7 (90% confidence limits 2.3-14.3, p= 0.03). /Phenoxyherbicides, chlorophenols, arsenic, and sodium pentachlorophenate/|For more Human Toxicity Excerpts (Complete) data for 4-(2,4-DICHLOROPHENOXY)BUTYRIC ACID (14 total), please visit the HSDB record page.

2,4 DM

Soluble concentrate; emulsifiable concentrate.

Chlorophenoxy herbicides are applied alone or as mixtures with other herbicides, in solutions, dispersions, or emulsions in water &/or oil, using equipment that produces large droplets to avoid spray drift. /Chlorophenoxy herbicides/|New Zealand: The spraying of phenoxyherbicides is restricted within prescribed distances of vineyards. /Phenoxyherbicides/

A PROCEDURE FOR DETECTING CHLOROPHENOXY HERBICIDES IN WATER IS DESCRIBED. EXTRACTED WITH BENZENE, THE EXTRACT IS DILUTED WITH ACETONE TO A SUITABLE VOLUME FOR GAS-LIQUID CHROMATOGRAPHY. THE RESULTS INDICATE THAT THE EXTRACTION METHOD WOULD BE APPLICABLE FOR DETERMINING POSSIBLE WATER CONTAMINATION BY CHLOROPHENOXY ESTERS. /CHLOROPHENOXY HERBICIDES/|EPA Method 515. Capillary Column Gas Chromatography with electron capture detection for the determination of chlorinated herbicides in drinking water. For 4-(2,4-dichlorophenoxy)butyric acid the estimated detection limit is 0.07 ug/l, and the method detection limit is 0.91 ug/l. Using the packed column, mean recovery is 93% with a standard deviation of 3%, with a spike level of 10.3 ug/l in reagent water. Using a capillary column, mean recovery is 63% with a standard deviation of 32% at a spike level of 4.02 ug/l.|EPA Method 8150. Gas Chromatography for the analysis of chlorinated herbicides including 4-(2,4-dichlorophenoxy)butyric acid in solid waste. For the analysis of unfamiliar samples, compound identification should be supported by at least one additional qualitative technique. Detection is achieved with an electron capture, microcolorimetric, or electrolytic conductivity detector. For 4-(2,4-dichlorophenoxy)butyric acid, the method has a detection limit of 0.91 ug/l. Using reagent water and a spike concentration of 10.3 ug/l, a mean recovery of 93% and a standard deviation of 3% were obtained. Interferences include organic acids and phenols.|Mixed formulations of phenoxyalkanoic acids and other common selective herbicides (dicamba, 2,4-D, ioxynil, etc.) available in the market were analyzed by HPLC using a 7 um "Zorbax" ODS column. Most formulations, including amine and sodium salts, can be analyzed directly, by prepg. the solns. in the mobile phase. Some formulations require extraction with CHCl3 to remove interfering additives. Prepared solutions (10 ul) are injected into the column and the cmpd detected using an UV spectrophotometer operating at 280 nm. The method is simple, rapid, and specific, requiring no derivatization. The method saves more than 75% of the time used for sample preparation when using conventional GC derivatization techniques.|For more Analytic Laboratory Methods (Complete) data for 4-(2,4-DICHLOROPHENOXY)BUTYRIC ACID (15 total), please visit the HSDB record page.

A simple HPLC assay for 8 chlorophenoxy (2,4-D and related compds.) and 2 benzonitrile (bromoxynil and ioxynil) herbicides has been developed to aid in the diagnosis of acute poisoning. Sample (whole blood, plasma/serum, urine, or tissue homogenate) after centrifugation is analyzed on a 250 x 5 mm (internal diam.) Spherisorb S5 Ph column, with aq potassium dihydrogen orthophosphate (50 mmol/l, pH 3.5) and acetonitrile (3:1 by vol) as eluent. The method is capable of resolving the chlorophenoxy/benzonitrile mixts. The limit of detection (at 240 nm) is 20 mg/l (10 mg/l for bromoxynil and ioxynil). Intra-assay and interassay relative standard deviations were <5% and <8%, respectively, for all analytes.|A method is detailed for detg. selected chlorinated phenols and phenoxy herbicides in urine. The process of preparing the samples includes acid hydrolysis, extaction with benzene, derivatization with diazoethane, and column chromatograhic cleanup. The more volatile cmpd were quantified by using capillary column GC/pos chemical ionization/MS/MS. Less volatile cmpd were quantified by using electron capture neg chemical ionization in a single stage mass spectrometry mode. Quality control samples were included in each analytical run. Pos values for the target analytes were determined on the basis of appropriate relative retention time, a signal-to-noise ratio >3:1, and a calculated concn >1 ppb. The chlorine isotope ratios were determined for each cmpd to assess the presence or absence of interferences. This analytical method was applied in a case control study of 199 individuals to examine exposure to the 12 target analytes.

Agrochemicals -> Herbicides|Herbicides|HERBICIDES

2,4-DB has known environmental transformation products that include 2,4-D.