• Archives of Pharmacal Research
• /
• v.26 no.2
• /
• pp.120-123
• /
• 2003

A method for the determination of terbutaline enantiomers in human urine by capillary elctrophoresis has been developed. Optimum resolution was achieved using 50 mM phosphate buffer, pH 2.5, containing 15 mM of hydroxypropyl-$\beta$-cyclodextrin as a chiral selector. Urine samples were prepared by solid-phase extraction with Sep-pak silica, followed by CE. The assay was linear between 2-250 ng/mL (R = 0.9998 for (S)-(+)-terbutaline and R = 0.9999 for (R)-(-)-terbutaline) and detection limit was 0.8 ng/mL. The intra-day variation ranged between 6.3 and 14.5% in relation to the measured concentration and the inter-day variation was 8.2-20.1%. It has been applied to the determination of (S)-(+)-terbutaline and (R)-(-)-terbutaline in urine from healthy volunteer dosed with racemic terbutaline sulfate.

• Journal of Environmental Health Sciences
• /
• v.36 no.1
• /
• pp.44-51
• /
• 2010

This study aimed to develop analytical method for 8-isoprostanes as biomarkers for oxidative stress with LC/MS/MS technique and to apply the method for human urine samples. Analyzed compounds for urinary oxidative stress markers were 7 stereo-isomers of prostaglandins and the internal standard (iso-$PGF_{2{\alpha}}-d_4$) was used to adjust the recovery rate. The method for determining urinary iso-$PGF_{2{\alpha}}$ consisted of solid phase extraction and LC/MS/MS detection. Separation of isomers of prostaglandins completed by porous graphitic carbon column and buffer solution. Detection limits for urinary markers of oxidative stress, iso-$PGF_{2{\alpha}}$ with LC/MS/MS were 0.01 ng/ml by S/N ratio 3 and 0.028 ng/ml by calculated as to FDA method. The recovery (92.8~101.9%) and precision (8.8~20.7%) of analysis were feasible for detecting iso-$PGF_{2{\alpha}}$ in real human urine samples. We detected 4 isomers of prostaglandins in human urine samples. Mean (standard deviation) of urinary iso-$PGF_{2{\alpha}}$ concentration were 0.231 (0.117) ng/mg creatinine for smoking group and 0.154 (0.082) ng/mg creatinine for non-smoking group.

• Analytical Science and Technology
• /
• v.33 no.1
• /
• pp.23-32
• /
• 2020

Methamphetamine (MA) is the most common and available drug of abuse in Korea and its primary metabolite is amphetamine (AP). Detection of AP derivatives, such as MA, AP, phentermine (PT), MDA, MDMA, and MDEA by the use of immunoassay screening is not reliable and accurate due to cross-reactivity and insufficient specificity/sensitivity. Therefore, the analytical process accepted by most urine drug-testing programs employs the two-step method with an initial screening test followed by a more specific confirmatory test if the specimen screens positive. In this study, a gas chromatography-mass spectrometric (GC-MS) method was developed and validated for confirmation of MA and AP in human urine. Urine sample (500 µL) was added with N-isopropylbenzylamine as internal standard and ethyl chloroformate as a derivatization reagent, and then extracted with 200 µL of ethyl acetate. Extracted samples were analysed with GC-MS in the SIM/ Scan mode, which were screened by Cobas c311 analyzer (Roche/Hitachi) to evaluate the efficiency as well as the compatibility of the GC-MS method. Qualitative method validation requirements for selectivity, limit of detection (LOD), precision, accuracy, and specificity/sensitivity were examined. These parameters were estimated on the basis of the most intense and characteristic ions in mass spectra of target compounds. Precision and accuracy were less than 5.2 % (RSD) and ±14.0 % (bias), respectively. The LODs were 3 ng/mL for MA and 1.5 ng/mL for AP. At the screening immunoassay had a sensitivity of 100% and a specificity of 95.1 % versus GC-MS for confirmatory testing. The applicability of the method was tested by the analysis of spiked urine and abusers' urine samples.

• Analytical Science and Technology
• /
• v.34 no.2
• /
• pp.68-77
• /
• 2021

Cannabis is one of the most abused drugs in Korea. The main psychoactive component in cannabis, Δ9-tetrahydrocannabinol, is metabolized to 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) and THCCOOH-glucuronide (THCCOOH-glu) in the human liver, whereby the amount of THCCOOH-glu found in urine is twice as high as that of THCCOOH. The analytical process adapted by the majority of urine drug-testing programs involves a two-step method consisting of an initial immunoassay-based screening test followed by a confirmatory test if the screening test result is positive. In this study, a qualitative gas chromatography-mass spectrometry (GC-MS) method was developed and validated for the detection of THCCOOH in human urine, where THCCOOH-glu was converted into THCCOOH by alkaline hydrolysis. For purification of the urine extract prior to instrumental analysis, high-speed centrifugation was used to minimize interference. In addition, an injection-port derivatization method using ethyl acetate and N,O-bis(trimethylsilyl)-trifluoroacetamide containing 1 % trimethylchlorosilane was employed to reduce the time required for derivatization, and an aliquot of the final solution was injected into the GC-MS. The method was validated by measuring the selectivity, limit of detection (LOD), and repeatability. The sensitivity, specificity, precision, accuracy, Kappa, F-measure, false positive, and false negative rate were determined by comparing the GC-MS results with those obtained using the immunoassay. The LOD was determined to be 0.32 ng/mL, while the repeatability was within 9.1 % for THCCOOH. Furthermore, a comparison study was carried out, whereby the screening immunoassay exhibited a sensitivity of 86.4 % and a specificity of 100 % compared to GC-MS. The applicability of the developed method was examined by analyzing spiked urine and forensic urine samples obtained from suspected cannabis abusers (n = 221).

• Bulletin of the Korean Chemical Society
• /
• v.31 no.12
• /
• pp.3517-3518
• /
• 2010

• Journal of environmental and Sanitary engineering
• /
• v.11 no.3
• /
• pp.1-7
• /
• 1996

Mandelic acid is the major metabolite and phenylglyoxylic acid is the minor metabolite of styrene in human. This study was conducted to investigate the correlation between exposure concentrations of styrene and concentration of the metabolites in urine The concentrations of metabolites in urine and exposure concentrations were measured in 60 workers who were occupationally exposed to styrene in FRP industry as well as paint industry and musical instrument manufacturing industry and the concentrations of metabolites in urine ware measured in 90 workers not occupationally exposed to styrene for review the background level in the unexposed population. The results obtained were as follows; 1. The mean exposure concentration is 16.6 $\pm $12.2 ppm (range 0.4-49.9ppm) in the styrene exposed workers. 2. The concentration of mandelic acid in urine collected at the end of shift from worker exposed 8 hours to 50ppm of styrene, based on extrapolation from correlation equations was 578.5 mg/g creatinine and 176.8 mg/g creatinine for next morning urine, the concentration of phenylglyoxylic acid in urine collected at the end of shift was 291.1 mg/g creatinine, 177.9 mg/g creatinine in next morning urine. In the sum of mandelic acid and phenylglyoxylic acid in the urine 870.2 mg/g creatinine in urine sampled at the end of shift corresponds to an exposure of 50ppm of styrene and 366.0 mg/g creatinine for next morning sample corresponds to 50ppm. 3. The correlation of the degree of exposed with sum concentration of mandeliacid and phenylglyoxylic acid in the urine was better(r=0.079 for end of shift, r=0.78 for next morning) than the correlation with single determinant measurement in urine(r=0.75 for mandelic acid at end of shift, r=0.73 for mandelic acid at next morning, r=0.69 for phenylglyoxylic acid at end of shift, r=0.62 for phenylglyoxylic acid at next morning). The monitoring of sum concentration of mandelic acid and phenylglyoxylic acid in urine is a valuable indicator of time weighted average daily exposure ti styrene. And the exposure standard of urinary metabolites produced by styrene should be set, in distinction urine at the end of shift from urine at next morning.

• YAKHAK HOEJI
• /
• v.26 no.4
• /
• pp.223-229
• /
• 1982

Uremia is associated with defective protein binding of weakly acidic drugs, whereas the protein binding of basic drugs tends to be normal. The exact chemical nature of compound(s) and mechanism for these changes as yet is unknown, and has not been defined. Organic solvent extraction of pooled normal human urine following hydrolysis by hydrochloric acid produced an extract, which when added to normal human serum, was capable of inducing binding defects similar to those in uremia. Binding defects were observed with the weakly acidic drugs such as nafcillin, salicylate, sulfamethoxazole and phenytoin while the binding of the basic drugs such as trimethoprim and quinidine were unaffected. The binding defects induced by the hydrolyzed urine extract could readily be corrected by same organic solvent extraction of acidified serum and the defects could be transferred to the normal human serum using the organic solvent layer at the physiologic pH (7.4). Followed by reacidification ind extraction of the binding defects induced serum with the same solvent, separated several fractions were obtained on thin-layer chromatography. One of these fractions could reinduce the binding defects and this factor(s) is apparently weakly acidic compounds and tightly bound to serum at physiologic pH, but extractable at acidic pH, and its molecular weight range is approximately 500 or less similar to those seen in uremia. These findings strongly support the hypothesis that the drug binding defect in uremia is due to the accumulation of endogenous metabolic products which arc normally excreted by the kidneys but accumulate in renal failure.

• Korean Journal of Food Science and Technology
• /
• v.41 no.2
• /
• pp.215-219
• /
• 2009

To conduct a risk assessment of $AFB_1$ intake, $AFM_1$, which is a metabolite of $AFB_1$ in the human and porcine urine, was determined by competitive direct ELISA (cdELISA). The detection limit of cdELISA using anti-$AFM_1$ antibody and $AFB_1$-HRP conjugate was 10 pg/mL. The recoveries of $AFM_1$ were 117-167% after the addition of $AFM_1$ in the human urine in a range of 3-100 pg/mL. 165 samples (95.5%) of those obtained from 172 persons evidenced measurable levels of urinary $AFM_1$. The detected $AFM_1$ ranges were 0-11.6 pg/mL and the average level of $AFM_1$ contamination was 2.74${\pm}$ 1.89 pg/mL. The estimated amount of $AFM_1$ excretion in the human urine was 3.97 ng/day and the estimated $AFB_1$ intake amount was 79.4 ng/day. The probable daily intake (PDI) of $AFB_1$ by the subjects was estimated to be 1.28 ng/kg bw/day, which was higher than the tolerable daily intake (TDI, 0.15 ng/kg bw/day). In the case of porcine urine, the $AFM_1$ ranged between 0.97-26.7 pg/mL and the average contaminated $AFM_1$ was 10.62${\pm}$4.39 pg/mL. The estimated amount of $AFM_1$ excretion in the porcine urine was 27.6 ng/day, and the estimated $AFB_1$ intake amount was 551 ng/day.

• Journal of Nutrition and Health
• /
• v.8 no.1
• /
• pp.65-69
• /
• 1975

Human chorionic gonadotropin hormone(H.C.G.) is secreted from the villus tissues of the placenta and excreted in lange amount into the urine. Its isolation is chiefly made from the urine of a pregnant woman. Recently, Matsushima attempted isolation of H.C.G. directly from the placenta itself. In order to prepare H.C.G. from human placenta, general method of extractiag and purifying proteins was applied. Its way was as follow: Crude H.C.G. was extracted from placenta with pH 9.0 and pH 5.0 aqua ammonia, and purified with pH 8.0 ammonia and 50% ethanol at pH 4.8. The purified H.C.G. showed two moving bands on the anode by paper electrophoresis. On the other hand, the H.C.G. from pregnancy urine (Standard. Pharm. Co.) showed same two bands but their moving ratio were different. The purified H.C.G. showed gonadotropin effect when it was injected young fomale rats 40r/cc per day for 5 days and weighted the increased ovary weight.

• Biomolecules & Therapeutics
• /
• v.4 no.3
• /
• pp.251-256
• /
• 1996

The metabolism of carbinoxamine, 2-[(4-chlorophenyl)-2-pyridinyl-methoxy]-N, N-dimethylethaneamine, was studied in adult male volunteers after an oral dose of 15 mg. Solvent extracts of urine obtained with or without enzyme hydrolysis were analyzed by gas chromatography-mass spectrometry after derivatization with MSTFA/TMSCl (N-methyl-N-trimethylsilyltrifluoroacetamide/trimethyl chlorosilane). The structures of metabolites were determined based on the electron impact (EI) and chemical ionization (CI) mass spectra. Nonconjugated metabolites identified in the urine were carbinoxamine, nor-carbinoxamine, and bits-nor-carbinoxamine. Parent drug, nor-carbinoxamine, and bits-nor-carbinoxamine were also detected as conjugated forms. These metabolites observed in human urine were different from those previously reported in the rat. Urinary excretions of carbinoxamine were reached to maxima in 4 hours after drug administration with 4.9%-8.1% and 2.5-4.2% of the dose excreted during 24 h as carbinoxamine and its glucuronide, respectively.