Chemical inducers of oviposition for the corn earworm, Heliothis zea (Boddie).

The corn earworm moth lays its eggs in the vicinity of triacetin, an ingredient of felt-tipped marking pens. Related compounds also induce this behavior. A bioassay was devised to measure the activity of chemicals as oviposition inducers.

Host-seeking stimulant for parasite of corn earworm: isolation, identification, and synthesis.

13-Methylhentriacontane has been identified in the feces and larvae of the corn earworm, Heliothis zea (Boddie), as the major constituent that triggers the short-range host-seeking response of the parasite Microplitis croceipes (Cresson). This chemical, the first found that mediates the complex host-parasite relation, could upgrade present efforts to use parasites for insect control. Bioassay of closely related compounds indicated that the structural requirements for activity are remarkably specific.

Comparison of fallopian tube intraluminal pathology as assessed by salpingoscopy with pelvic adhesions.

OBJECTIVE: To correlate the severity and extent of pelvic adhesions, as noted at laparotomy for microsurgery, with the presence and extent of fallopian tube intraluminal pathology, as noted using salpingoscopy. DESIGN: Prospective clinical study. SETTING: A university teaching hospital. PATIENTS: Twenty patients presenting for pelvic microsurgery between July 1992 and January 1993. INTERVENTIONS: Salpingoscopy was performed at the time of microsurgery and intraluminal pathology was scored. An objective assessment of the extent of pelvic adhesions was made using standardized adhesion score systems. RESULTS: There was a strong correlation between the degree of intratubal damage and the extent of pelvic adhesions when the etiology was previous pelvic inflammatory disease (PID) but not when the underlying etiology was endometriosis. However, in the endometriosis subgroup, intraluminal ampullary pathology was noted in 27% of tubes assessed, and intraluminal fimbrial pathology was noted in 36% of tubes assessed. Intraluminal tubal pathology also was noted in a number of cases where the underlying etiology was previous surgery for benign disease. CONCLUSIONS: This study confirms previous reports that, in cases of PID leading to adhesions, there is a high incidence of intraluminal pathology. However, this study also demonstrates that intraluminal pathology is often associated with adhesions arising from other etiologic groups, suggesting that intraluminal assessment is required for all patients in whom adhesiolysis for fertility is considered.

Determination of sodium saccharin in animal feed, wastewater and human urine by high-pressure liquid chromatography.

Analytical methods are described for sodium saccharin in animal feed, wastewater and human urine at levels as low as 10, 0.1 and 10 ppm, respectively. Samples of animal feed and wastewater are subjected to liquid-liquid partitioning then the feed is further cleaned up on a column of silica gel prior to analysis by high-pressure liquid chromatography (HPLC) using a paired-ion mobile phase and an ultraviolet detector set at 230 nm. Samples of human urine require a cleanpu on a column of XAD-2 prior to the partitioning and silica gel steps as well as an adjustment in the composition of the mobile phase to quantify saccharin. Data concerning partition values and the stability of sodium saccharin in animal feed are also presented.

A rapid procedure to efficiently clean blenders repeatedly used to prepare dosed feed for bioassays.

An effective and economical procedure is described to clean blending equipment repeatedly used to prepare dosed feed for animal bioassays. The cleanup procedure was evaluated with 2 types of blenders against 10 test chemicals with a broad spectrum of polarities by separately spiking the agents into feed at various levels. Analytical data illustrating the level of contamination at each interval of the multi-step cleanup procedure are presented for each test chemical. Analytical chemical methods and efficiencies of the cleaning steps with the feed admixtures are discussed. The procedure was tested and adopted for use at the National Center for Toxicological Research (NCTR).

Chemical monitoring of urine from workers potentially exposed to benzidine-derived azo dyes.

Benzidine (Bzd) and monoacetylbenzidine (MoAcBzd) were found in the urine of workers exposed to benzidine-based azo dyes. A colorimetric screening method, based on the reaction of extracted free aromatic amines with 2,4,6-trinitrobenzene-sulfonic acid (TNBS), was used with a specific electron-capture gas chromatographic (EC-GC) method. Alkaline hydrolyzable conjugates of Bzd and 2,4-diaminoazobenzene (DiAmAzBz) were found together with free DiAmAzBz and traces of 3,3'-dimethylbenzidine (DiMeBzd) and 3,3'-dimethoxybenzidine (DiMxBzd). The presence of a known human bladder carcinogen (Bzd) and its metabolites in the urine of workers exposed to benzidine-based azo dyes is a cause for concern.

Trace analysis of 2,4,5-trichlorophenoxyacetic acid, its glycineamide, and their alkaline hydrolyzable conjugates in mouse blood, urine, and feces.

Chemical methods were developed for the trace analysis of the herbicide 2,4,5-trichlorophenoxyacetic acid, its glycineamide, and their alkaline hydrolyzable conjugates in mouse blood, urine, and feces. The salient elements of the methods are extraction of the free acids with benzene, methylation, cleanup on a silica gel column, and quantification via electron-capture GLC. Any unextracted conjugates remaining in the substrates are then subjected to alklaline hydrolysis, and the liberated 2,4,5-trichlorophenoxyacetic acid is assayed. Data are presented concerning recoveries of the compounds from the three spiked substrates. The utility of the procedures is illustrated by a preliminary pharmacolinetic study employing parallel electron-capture GLC and radioassays of the three substrates from mice injected with a single intravenous dose of 14C-2,4,5-trichlorophenoxyacetic acid. GLC characteristics and partition values of the the compounds and hydrolysis of the glycineamide under various conditions also are discussed.

Removal of trace levels of 2-acetylaminofluorene (2-AAF) from wastewater.

An adsorption system is described for the removal of part per billion levels of the chemical carcinogen, 2-acetylaminofluorene (2-AAF), from industrial wastewater. The system consists primarily of filters and activated carbon and non-ionic polymeric adsorbents arranged in tandem. It is highly efficient, operates at low cost, and requires minimal attention. The chemical monitoring of the raw and/or cleaned-up wastewater is based on a highly sensitive and specific spectrophotofluorometric method that allows acceptance or rejection of samples at the 0.2 part per billion level. The system is presented as a model for evaluating the removal of traces of organic chemicals from wastewater prior to recycling or discharging it into the environment. Results of laboratory evaluations of several other approaches to the purification of 2-AAF-containing wastewater are also presented.

A "marker" technique to monitor treated industrial wastewater effluents.

In toxicological research with hazardous substances (e.g. carcinogens), wastewater effluent from the test facility must be free of such substances before discharge into the environment. An industrial wastewater processing employing adsorbers of carbon and XAD-2 resin is described; however, chemical assays of each batch of treated effluent must certify the absence of all test agents. Elution profiles and adsorption isotherm tests with the test agents vs. the two adsorbents provided the basis for a "marker" technique which should eliminate the necessity to assay for all test agents in each batch of processed effluent. A radionale is presented for periodic introduction of a "marker" (gentian violet) into the primary adsorbers. If detected in the effluent, the "marker", which elutes from the adsorbers before most of the test agents would signal impending depletion of the adsorbent which could then be replaced. Recommendations to modify the industrial wastewater treatment plant and to implement the "marker" technique are presented as cost-effective alternatives to extensive and laborious chemical assays.

Analysis, purification and stability: requirements for a metabolism study of an azo dye and pigment.

Impurities of aromatic amines in the azo dye and pigment, Direct Black 38 and Pigment Yellow 12, and in vitro stability of the dye were determined. These factors can affect the results of studies designed to ascertain whether the two compounds are metabolized to potential carcinogens in hamsters. Procedures for removing impurities from the two compounds are also presented. Electron-capture gas chromatography of the heptafluorobutyryl derivatives of the impurities and degradation products was used to satisfy all the analytical requirements of the experiments. Major impurities found in Direct Black 28 were benzidine, 4-aminobiphenyl and 2,4-diaminoazobenzene; whereas, only 3,3'-dichlorobenzidine was found in Pigment Yellow 12. Stability studies of the purified dye conducted in water and in urine from hamsters and humans indicated that the dye would not degrade under the conditions used for collecting and assaying samples from a metabolism experiment. However, within 48 hours at 25 and 37.5 degrees C, the dye did degrade to known carcinogens in both hamster and human urine. Such degradation not only points out the need for proper storage of samples from metabolism studies but suggests that industrial effluents containing the dye should be properly treated before release into the environment.

Metabolism of a dimethylbenzidine-based dye in rats and hamsters as determined by analysis of the urine for potentially carcinogenic aromatic amines.

Direct Red 2 was given as an aqueous solution to rats and hamsters to determine whether the dye is cleaved to potentially carcinogenic aromatic amines. Sensitive and specific assays of the urine from treated animals by EC/GC revealed appreciable levels of 3,3'-dimethylbenzidine, mono- and di-acetyldimethylbenzidine, and alkaline hydrolyzable conjugates. Peak concentrations of the metabolites in urine occurred 12 to 24 hours after administration to rats, and within 12 hours in hamsters. The levels of all metabolites and conjugates diminished rapidly in both species after peak concentrations were reached, with no residues detected after 96 hours. The results conclusively demonstrated in vivo cleavage of the dye in both species, and it is proposed that the analytical methods employed can be used for chemical monitoring of human urine.

Chromatographic assays for traces of potentially carcinogenic metabolites of two azo dyes, Direct Red 2 and Direct Blue 15, in rat, hamster and human urine.

Specific, precise and sensitive methods are described for determining traces of potentially carcinogenic metabolites of Direct Red 2 and Direct Blue 15 in rat and hamster urine and to monitor the urine from workers who may be occupationally exposed to these dyes. This methodology is generally applicable to metabolites of azo dyes based on benzidine or three of its congeners. The benzidine-congener free amines, their mono and diacetylated analogs and alkaline hydrolyzable conjugates were determined after appropriate extraction and hydrolysis by HPLC or EC/GC. Residues of metabolites in rat, hamster, and human urine were determined at levels as low as 1 ppb. Supplementary information is also presented concerning hydrolysis of diacetylated metabolites and the stability of Direct Red 2 and Direct Blue 15 in rat, hamster and human urine.

Determination of tibric acid and clofibrate in animal feed, wastewater and hunan urine.

Analytical chemical procedures are described to determine residues of the drugs clofibrate and tibric acid in animal feed, wastewater, and human urine. Clofibrate was extracted from animal feed and human urine with hexane, whereas residues from wastewater were collected on a Sep-PakTM then eluted with methanol for analysis. Clofibrate residues from the feed, wastewater, and urine were analyzed by high-pressure liquid chromatography (HPLC) with minimum detectable levels (MDL) of about 40, 0.5 and 1.0 ppb, respectively. Tibric acid was extracted from animal feed with 90% methanol and 10% 0.1 N NaOH, whereas wastewater and human urine were acidified with 12 N HCl and then extracted with benzene. The MDL for tibric acid in feed by electron capture/gas chromatography (EC/GC) and HPLC were about 40 ppb and 2.0 ppm, respectively. Residues from these extracts that contained more than 5 ppm of tibric acid were analyzed by HPLC, whereas GC was required for levels below 5 ppm. The GC procedures, which required that tibric acid be derivatized (methylated) prior to analysis, had MDL of 0.1 and 1.0 ppb for wastewater and human urine, respectively. Data are also presented concerning partition values, stability of the compounds in animal feed, and recoveries of the compounds from the three substrates.

Benzidine-congener-based azo dyes: assays for purity and residues in feces from dosed rats.

Analytical methods were required to determine purities of benzidine-congener-based azo dyes and residues of the intact dyes in feces from rats before valid metabolism studies of such compounds could be conducted. A procedure is described for purity assays based on reduction of the dyes with stannous chloride followed by gas chromatography of the released free amine. Sixteen different samples of commercial dyes based on three benzidine congeners were assayed; purities ranged from 26.4 to 83.4%. Several dyes were also shown to be partially purified by cold water washes. A method to determine two intact dyes in feces from dosed rats, which consisted of extraction with dimethylformamide: water, clean-up by a rapid procedure using an octadecylsilane column, and quantification by ion-pair high-pressure liquid chromatography (HPLC) is reported. minimum detectable levels of both dyes in feces are 0.2 ppm. Excretion profiles based on parallel HPLC and radioassays of feces from rats dosed with 14C-labeled Direct Blue 15 and Direct Red 2 are presented. Based on radioassays, about 74% of each dose was excreted via the feces; however, HPLC assays showed that only about 11% of each dose was present as intact dye in the excrement.

Metabolism and distribution of two 14C-benzidine-congener-based dyes in rats as determined by GC, HPLC, and radioassays.

Absorption, metabolism and tissue distribution studies were conducted in the rat with 14C-biphenyl ring-labeled Direct Blue 15, a 3,3'-dimethoxybenzidine (DiMxBzd) based azo dye; Direct Red 2, based on 3,3'-dimethylbenzidine (DiMeBzd) and corresponding benzidine congener amines. Single oral doses of the 14C-labeled dyes (12 mg/kg, 62 microCi/kg) and molar equivalent doses of the respective amines were administered and urine and fecal samples collected at intervals up to 192 hours. Urine specimens were analyzed for 14C content and further characterized by EC/GC for free amines, acetylated metabolites, and conjugates. Feces were assayed for 14C content and for unchanged dosed dyes or amines by HPLC. A comparison of the metabolism of Direct Blue 15 with its base DiMxBzd, indicated that the base was more extensively metabolized and that most of the 14C in various extracts was identified as known metabolites. The metabolism of Direct Red 2 compared with its base, DiMeBzd, indicated that the base was more extensively metabolized, yet only a small percentage of the 14C in extracts was identified as known metabolites. Most of the 14C present in the urine could not be extracted with benzene nor chloroform, indicating high polarity. Distribution studies conducted with both dyes showed that liver, kidney, and lung accumulated and retained higher levels of 14C than other tissues (at 72 hrs). Peak levels of 14C, which occurred 8-12 hours after dosing, were significantly higher with Direct Red 2 than Direct Blue 15. Tissue distribution data (72 hr) for rats dosed with the free amines compared with the dyes showed a generally lower but similar distribution pattern.

Metabolism of nine benzidine-congener-based azo dyes in rats based on gas chromatographic assays of the urine for potentially carcinogenic metabolites.

Metabolism experiments were conducted with rats dosed with nine azo dyes based on dimethyl-, dimethoxy-, or dichlorobenzidine to determine whether the free amine congeners, their monoacetyl or diacetyl metabolites, or alkaline hydrolyzable conjugates were excreted in the urine. After preliminary tests of the dyes, 2-mg doses were administered to each animal and urine samples were collected at intervals up to 96 hours. EC/GC procedures were based on the analysis of heptafluorobutyryl derivatives of the free amine congener moieties or their monoacetyl metabolites. Peak levels of metabolites were excreted either 0-12 or 12-24 hours after administration and, in seven of nine instances, no metabolites persisted in the urine after 48 hours. Minimum detectable levels of all metabolites were 12 ppb or less. All nine dyes were shown to be converted to measurable levels of their benzidine-congener-based metabolites in rats.

Analysis of insect chemosterilants.

Background information concerning the concept of insect chemosterilization and analytical methods for determining trace levels of 19 P- and/or S- containing chemicals of current interest are presented. GC retention times of the compounds on 6 different columns and their p-values in 11 solvent systems are tabulated. The utility of the flame photometric detector for determining subnanogram levels of the sterilants in biological substrates is illustrated.

Determination of sodium phenobarbital in animal chow by high-pressure liquid chromatography.

An analytical procedure is described for determining residues of sodium phenobarbital in animal chow at levels as low as 0.14 ppm. The methanol extract is subjected to a liquid-liquid cleanup at pH 13 and 1, further cleaned up on a silica gel column and assayed by high-pressure liquid chromatography by using an ultraviolet absorption detector at 210 nm. Data concerning extraction efficiency, partition values and stability of the chemical in animal chow are also presented.

Determination of gentian violet in animal feed, human urine, and wastewater by high pressure liquid chromatography.

Sensitive and specific procedures are described for the analysis of residues of gentian violet in animal feed, human urine, and wastewater at levels of 1000 ppm down to 10 ppb, 1 ppb, and 10 ppb, respectively. The cleaned-up extracts were analyzed by reverse-phase high pressure liquid chromatography by using an absorption detector at 588 nm. Recoveries of the compound from animal feed, human urine, and wastewater at the 10 ppb level were 79%, 58%, and 60%, respectively. Information concerning the stability of the compound in animal feed and the efficiency of extracting the residues is presented. Ancillary information is also reported concerning the separation and analysis of six related triphenylmethane dyes.

Trace analysis of potentially carcinogenic metabolites of an azo dye and pigment in hamster and human urine as determined by two chromatographic procedures.

Analytical chemical procedures are described for determining traces of possible metabolites of two azo compounds. Direct Black 38 and Pigment Yellow 12, in hamster urine and to monitor the urine from workers who may be occupationally exposed during the manufacture or use of the dye and pigment. These methods were required for metabolism studies designed to assess the hazards that may occur if the two compounds are converted by in vivo mechanisms to potential carcinogens. Salient elements of the procedure are: extraction of the free aromatic amines and neutral compounds; alkaline hydrolysis of the aqueous phase and extraction of any hydrolyzed conjugates as free amines, and the analysis of the free amines and acetylated metabolites directly by high pressure liquid chromatography or by electron capture gas chromatography after conversion of the amines to heptafluorobutyryl derivatives. Residues of metabolites in hamster and human urine were determined at levels as low as 1 ppb. Ancillary data concerning hydrolysis of diacetylated metabolites and partition values for possible metabolites in various solvent systems are also presented.