• Asian Pacific Journal of Cancer Prevention
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• 제17권10호
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• pp.4761-4767
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• 2016

Objective: The use of Shamma (smokeless tobacco) by certain groups is giving rise to health problems, including cancer, in parts of Saudi Arabia. Our objective was to determine metals levels in Shamma using inductively coupled plasma mass spectrometry (ICP-MS). Methods: Thirty-three samples of Shamma (smokeless tobacco) were collected, comprising four types: brown Shamma (n = 14.0), red Shamma (n = 9.0), white Shamma (n = 4.0), and yellow Shamma (n = 6.0). All samples were collected randomly from Shamma users in the city of Najran. Levels of 11 elements (Al, As, Cd, Co, Cr, Cu, Li, Mn, Ni, Pb, and Zn) were determined by ICP-MS. Results: A mixed standard (20 ppb) of all elements was used for quality control, and average recoveries ranged from 74.7% to 112.2%. The highest average concentrations were found in the following order: Al ($598.8-812.2{\mu}g/g$), Mn ($51.0-80.6{\mu}g/g$), and Ni ($23.2-53.3{\mu}g/g$) in all four Shamma types. The lowest concentrations were for As ($0.7-1.0{\mu}g/g$) and Cd ($0.0-0.06{\mu}g/g$). Conclusions: The colour of each Shamma type reflects additives mixed into the tobacco. Cr and Cu were showed significant differences (P < 0.05) among Shamma types. Moreover, Pb levels are higher in red and yellow Shamma, which could be due to use (PbCrO4) as yellow colouring agent and lead tetroxide, Pb3O4 as a red colouring agent. The findings from this study can be used to raise public awareness about the safety and health effects of Shamma, which is clearly a source of oral exposure to metals.

• Plant Biotechnology Reports
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• 제2권4호
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• pp.245-252
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• 2008

The genetic status of somatic embryo-derived plantlets of Cymbopogon flexuosus was examined by randomly amplified polymorphic DNA (RAPD) analysis. Auxins such as 2, 4-dichlorophenoxyacetic acid (2, 4-D) (1-4 mg/l) were used in Murashige and Skoog (MS) medium for induction of calli from rhizomatous explants of Cymbopogon flexuosus. Optimum calli were induced on MS medium supplemented with 2, 4-dichlorophenoxyacetic acid (2, 4-D) (3.5 mg/l) alone or in combination with $N^6-benzyladenine$ (2 mg/l). Somatic embryogenesis was achieved from long term calli when cultured on MS medium containing 2, 4-dichlorophenoxyacetic acid (2, 4-D) (2 mg/l) along with $N^6-benzyladenine$ (BA) (1-2 mg/l). Regeneration was achieved when freshly induced embryogenic calli were sub-cultured on MS medium supplemented with $N^6-benzyladenine$ (3 mg/l) alone. Long-term cultured embryos showed profuse minute rooting on regeneration medium supplemented with N6 -benzyladenine (3 mg/l). Microshoots were rooted in the presence of indole-butyric acid (IBA) (2 mg/l). DNA samples from the mother plant and 18 randomly selected regenerated plants from a single callus were subjected to RAPD analysis with 6 arbitrary decamer primers for the selection of putative somaclones. A total of 64 band positions were scored, out of which 19 RAPD bands were polymorphic. From genetic similarity coefficient based on RAPD band data sharing, it was found that the majority of the clones were almost identical or more than 92% similar to the mother plant, except CL2 and CL9 (66%) which showed highest degree of genetic change with CL2 and CL9 showing presence of two non-parental bands each.

• Mass Spectrometry Letters
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• 제5권1호
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• pp.24-29
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• 2014

An advanced and reliable high performance liquid chromatography (HPLC)/ultraviolet detector (UV)/ion-trap time-of-flight (IT-TOF) mass spectrometry was developed for the simultaneous quantification of 19 marker compounds in Bang-poong-tong-sung-san (BPTS), a traditional oriental prescription. Various parameters affecting HPLC separation and IT-TOF detection were investigated, and optimized conditions were identified. The separation was achieved on a Capcell PAK C18 column ($1.5mm{\times}250mm$, $5{\mu}m$ particle size) using a gradient elution of acetonitrile and water containing 0.1% formic acid at a flow rate of 0.1 mL/min. The column temperature was maintained at $40^{\circ}C$ and the injection volume was $2{\mu}L$. IT-TOF system was equipped with an electrospray ion source (ESI) operating in positive or negative ion mode. The optimized electrospray ionization parameters were as follows: ion spray voltage, +4.5 kV (positive ion mode), or -3.5 kV (negative ion mode); drying gas ($N_2$), 1.5 L/min; heat block temperature, $200^{\circ}C$. Automatic $MS^n$ (n = 1~3) analyses were carried out to obtain structural information of analytes. Elemental compositions and their mass errors were calculated based on their accurate masses obtained from a formula predictor software. The marker compounds in BPTS were identified by comparisons between $MS^n$ spectra from standards and those from extracts. Moreover, the libraries of $MS^2$ and $MS^3$ spectra and accurate masses of parent and fragment ions for marker compounds were constructed. The developed method was successfully applied to the BPTS extracts and identified 17 out of 19 marker compounds in the BPTS extracts.

• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1508-1512
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• 2004

A gas chromatography/mass spectrometric (GC/MS) method has been developed for the determination of trace mono-n-butyltin (MBT), di-n-butyltin (DBT), and tri-n-butyltin (TBT) compounds in sediments. Samples were extracted by 10% acetic acid in methanol containing 0.03% tropolone and were then derivatized for GC/MS analysis. Ethylation by sodium tetraethylborate and phenylation by sodium tetraphenylborate were evaluated as a derivatization reaction of the organotins in sample extract. n-Hexane was added into reaction media in the beginning of the reaction for the continuous extraction of derivatized organotins. Ethylation requires less than 2 hours to get proper derivatization yields for MBT, DBT, and TBT altogether and produces relatively low amounts of side reaction products. Compared to ethylation, phenylation requires much longer time but provides relatively lower yield and produces considerable amounts of side reaction products. Therefore, the ethylation reaction was applied for the analysis of organotin compounds in sediment. An isotope dilution mass spectrometric (IDMS) method based on GC/MS has been applied to the accurate determination of DBT compounds in the sediments. The IDMS results from the analyses of sediment samples showed a reasonable repeatability and a good agreement with the values obtained by IDMS based on liquid chromatography/induced coupled plasma/mass spectrometry.

• 농약과학회지
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• 제19권1호
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• pp.1-4
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• 2015

잔류성 유기오염물질인 과불화합물 중 perfluorooctanesufonic acid (PFOS)와 perfluorooctanoic acid (PFOA)의 잔류분석은 환경부 "잔류성 유기오염물질 공정시험기준"에 따라 hydrophilic-lipophilic balance (HLB) solid phase extraction (SPE) 전처리 후 LC-$MS^n$를 이용해 정량 분석하고 있다. 본 연구에서는 환경부 설정 공정시험법에 따라 농업용수 전처리 후, 시험법에서 제거하지 못한 미지의 불순물을 Envi-Carb$^{TM}$을 통해 회수율에 영향을 주지 않고 손쉽게 제거하였다. 또한, 과불화합물 분석에 사용되는 LC-$MS^n$ 중 quadrupole-time-of-flight mass spectrometry (qTOFMS)에서 측정된 PFCs의 정량한계를 평가한 결과, 시험에 사용된 장비간 정량한계 편차가 크게 관찰되었으나, 시험대상 장비 모두 농업용수 중 ng/L 수준으로 잔류하는 과불화합물의 정밀 잔류분석에 사용가능 한 것으로 확인되었다.

• 약학회지
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• 제48권3호
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• pp.207-212
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• 2004

An analytic method was developed for the quantitation of $\Delta$$^{9}-$ tetrahydrocannabinol (THC) and 11-nor-9-carboxy THC (THC-COOH) in human hair. After hair samples were pulverized using Freezer Mill, deuterated internal standards were added and digested in 1 N NaOH at $100^{\circ}C$ water bath for 30 min. Digest solutions were extracted by 5 ml hexane：ethyl acetate (90：10) after acidification with acetic acid. The organic phase was evaporated under N 2 and derivatized by BSTFA (with 1% TMCS) at $85^{\circ}C$ for 45 min. The derivatized solution was separated on HP-5MS column ($30m{\times}0.25mm{\times}0.25mm$) and detected using EI-GC-MS with selective ion monitoring mode. The assay of calibration was ranged from 5 to 100 ng/50 mg hair ($r^2$＞0.99) for THC and THC-COOH. Within and between-run precision were calculated at 6, 30, 60 ng/50 mg hair with coefficients of variation less than 11%. Within and between run accuracies at the same concentrations were$\pm$14% and $\pm$30% of target for both analytes, respectively. Absolute and relative recovery at 10 and 100 ng were 60∼91％. The method was used to detect and quantify THC and THC-COOH in cannabis abuser's hairs (N = 16) and SRM (N=5, THC 1 ng/mg, NIST). We detected THC and THC-COOH in only one hair sample. In SRM, % accuracy was 93% (range 86∼103%) and precision (% CV) was 8.14. We began to set up a quantitative analysis of THC and THC-COOH using EI-GC-MS. Continuously, we need to modify and develop this method in order to apply for identification in cannanbis users' hair.

• Journal of Ginseng Research
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• 제45권5호
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• pp.539-545
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• 2021

Background: Red ginseng polysaccharides (RGPs) have been acknowledged for their outstanding immunomodulation and anti-tumor activities. However, their studies are still limited by the complexity of their structural features, the absence of purification and enrichment methods, and the rarity of the analytical instruments that apply to the analysis of such macromolecules. Thus, this study is an attempt to establish a new mass spectrometry (MS)-based analysis procedure for RGPs. Methods: Saponin pre-excluded powder of RG (RG-SPEP, 10 mg) was treated with 200 µL of distilled water and centrifuged for 5 h at 1000 rpm and 85 ℃. Ethanol-based precipitation and centrifugation were applied to obtain RGPs from the heated extracts. Further, endo-carbohydrase treatments were performed to produce specific saccharide fragments. Solid-phase extraction (SPE) processes were implemented to purify and enrich the enzyme-treated RGPs, while matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) MS was employed for the partial structural analysis of the obtained RGPs. Results: Utilizing cellulase, porous graphitized carbon (PGC), hydrophilic interaction chromatography (HILIC), and MALDI-TOF/TOF MS, the neutral and acidic RGPs were qualitatively analyzed. Hex_n and Hex_n-18 (cellulose analogs) were determined to be novel neutral RGPs. Additionally, the [Unknown + Hex_n] species were also determined as new acidic RGPs. Furthermore, HexA_n (H) was determined as another form of the acidic RGPs. Conclusion: Compared to the previous methods of analysis, these unprecedented applications of HILIC-SPE and MALDI-TOF/TOF MS to analyze RGPs proved to be fairly effective for fractionating and detecting neutral and acidic components. This new procedure exhibits great potential as a specific tool for searching and determining various polysaccharides in many herbal medicines.

• 한국작물학회지
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• 제30권3호
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• pp.271-276
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• 1985

벼 약배양에 있어서 기본배지 및 배지내 첨가물질이 callus유기와 식물체분화에 미치는 영향을 구명하기 위하여 시험한 결과는 다음과 같다. 1. callus 유기 및 식물체분화는 N$_{6}$기본배지에서 가장 높았으며 Indica형 품종보다는 Japonica형 품종에서 그 효율이 더욱 높게 나타났다. 2. 약치상후 callus유기는 기본배지의 종류에 관계없이 20~40일 사이에 90% 이상이 유기되었다. 3. 식물체분화는 callus유기배지의 영향을 크게 받으며 Miller 배지에서 유기된 callus의 식물체분화는 N$_{6}$나 MS배지에 비하여 저조하였다. 4. N$_{6}$배지내에 포함된 질소원중 (NH$_4$)$_2$SO$_4$의 함량을 31.5mM로 조절하였을 때 callus 및 식물체분화율이 향상되었다. 5. 생장조정제 첨가에 있어 2,4-D단독 처리보다는 NAA 2mg/$\ell$에 Kinetin 1mg/$\ell$를 혼용 처리하였을 때 callus유기 뿐 아니라 식물체분화율도 향상되었다. 6. Indica형 품종의 callus유기에 대한 DL-Ala-nine 첨가효과는 약을 저온처리하였을 때 높게 나타났다.

• 분석과학
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• 제14권5호
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• pp.392-399
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• 2001

생물시료에 존재하는 휘발성 유기화합물 중 n-butylbenzene과 1,2-dibromo-3-chloropropane (DBCP)를 기체크로마토그래피/질량분석기-선택이온검색법에 의해 수행하였다. 시료 중 휘발성 유기화합물은 $100{\mu}m$ polydimethyl siloxane (PDMS) fiber를 사용하여 headspace solid phase microextractio (SPME) 및 purge & trap 방법에 의해 추출 및 비교하였다. SPME에 의한 회수율은 n-butylbenzene의 경우 85.8%, DBCP의 경우 92.4%로 나타났고 검출한계는 각각 $0.15{\mu}g/kg$, $0.05{\mu}g/kg$로 나타났다. 반면, purge & trap의 경우 회수율은 n-butylbenzene의 경우 115.2%, DBCP의 경우는 80.9%로 나타났고 검출한계는 각각 $0.04{\mu}g/kg$ 및 $0.70{\mu}g/kg$로 나타나 두 방법에 있어 국내에서 규제하는 검출한계측면에서 큰 차이는 없었다.

• 대한전자공학회논문지SD
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• 제46권4호
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• pp.53-63
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• 2009

본 논문에서는 IEEE 802.11n 표준과 같은 근거리 무선통신망 응용을 위한 10비트 100MS/s 27.2mW $0.8mm^2$ 0.18um CMOS ADC를 제안한다. 제안하는 ADC는 고속 동작에 적합한 3단 파이프라인 구조를 기반으로 제작되었으며 각단에 공통적으로 사용되는 증폭기, 프리앰프 및 저항열을 최대한 효율적으로 공유함으로써 전력 소모 및 면적을 최소화하였다. 첫 번째 MDAC과 두 번째 MDAC에는 스위치 저항과 메모리 효과가 없는 증폭기 공유기법을 사용하였고, 세 개의 4비트 flash ADC에는 단 하나의 저항열만을 사용하는 동시에 두 번째 flash ADC와 세 번째 flash ADC에는 프리앰프를 공유하여 전력 소모와 면적을 최소화하였다. 보간 기법을 사용하여 요구되는 프리앰프의 수를 반으로 줄였으며, 프리앰프의 공유 및 보간 기법으로 인한 영향을 최소화하기 위해 낮은 킥-백 잡음을 갖는 비교기를 추가로 제안하였다. 제안하는 시제품 ADC는 0.18um 1P6M CMOS 공정으로 제작되었으며, 측정된 DNL 및 INL은 10비트 해상도에서 각각 최대 0.83LSB와 1.52LSB의 수준을 보이며, 동적 성능으로는 100MS/s의 동작 속도에서 각각 52.1dB의 SNDR과 67.6dB의 SFDR을 갖는다. 시제품 ADC의 칩 면적은 $0.8mm^2$이며 전력 소모는 1.8V 전원 전압을 인가하였을 때 100MS/s에서 27.2mW이다.