• 환경위생공학
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• 제23권4호
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• pp.37-44
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• 2008

In this study we developed the analytical methods for the determination of three neurotoxin; anatoxin-a, saxitoxin and neosaxitoxin using HPLC/FLD system and this analytical methods were applied to real sample; algae culture and algae extracts. For the HPLC/FLD analysis of anatoxin-a samples were concentrated on WCX(Weak Cation Exchanger) SPE and then anatoxin-a in concentrate was derivatized with NBD-F solution. Supernatant was injected on HPLC system. For the HPLC/FLD analysis of saxitoxin and neosaxitoxin samples were separated on the column and then derivatizied by post column reactor for fluorescen detection. For post column reaction of saxitoxin we feed two kinds of reaction solution; Oxidizing Reagent of which composition was periodic acid(7mM) in 50mM potassium phosphate buffer, pH 9 and acidifying reagent of which Composition was 0.5M acetic acid. The LOD value for anatoxin-a, saxitoxin and neosaxitoxin in HPLC/FLD method was 24.3 ng. $35{\mu}g/L$, $27{\mu}g/L$ respectively. We determined the anatoxin-a content of lyophilized anabaena flos-aquae and $20{\mu}g/g$ d.w. of anatoxin-a was detected. We analyzed saxitoxin and neosaxitoxin in algae culture media and extracts of lypopyllized algal cell cultured and that of Deachung reservior. Saxitoxin and neosaxitoxin in real sample were below the limit of detection. Although there are various water treatment processes for removing neurotoxins were suggested no process give simultaneous and complete removal of neurotoxins. It was cocluded that nanofiltration which reject material by size can be a process for removal of neurotoxins.

• 분석과학
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• 제34권3호
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• pp.122-127
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• 2021

Polyvinylpyrrolidone과 1,2-indanedione 혼합물(PVP-IND)은 감열지에 부착된 잠재지문을 현출하는데 가장 좋은 시약이라고 알려져 있다. 그러나 PVP-IND가 감열지에 부착된 혈흔지문을 증강할 수 있는지에 대해서는 알려지지 않았으므로 PVP-IND의 혈흔지문 증강 능력을 연구하였다. 비교 대상으로는 감열지에 부착된 혈흔지문을 증강할 때 가장 우수한 성능을 나타낸다고 알려진 amido black 수용액을 이용하였다. 그 결과, 물에 희석된 혈액이 묻은 손가락으로 만든 혈흔지문을 증강할 경우에는 PVP-IND가 amido black 수용액보다 증강 능력이 우수했다. 반면 희석되지 않은 혈흔지문을 PVP-IND로 처리하면 융선이 번져 나타나서 amido black 수용액의 증강 능력이 우수했다. PVP-IND로 처리했을 때 융선이 번져서 나타나는 것은 PVP와 혈액에 포함된 amino acid가 반응했기 때문인 것으로 추정된다.

• 분석과학
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• 제35권3호
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• pp.124-128
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• 2022

혈액을 증강하기 위해 사용하는 시약은 혈액 이외의 다른 물질의 영향을 받아 위양성 혹은 위음성을 나타낼 수 있다. 이런 반응이 일어나면 혈액 증거를 잘못 해석할 수 있으므로 혈흔 증강 시약의 위양성 및 위음성 가능성에 대한 조사는 필수적이다. 산성 과산화수소(acidic hydrogen peroxide, AHP)는 최근에 알려진 혈액 증강 시약으로, 위양성 혹은 위음성을 유발하는지에 대해 알려진 바가 없다. 이를 확인하기 위해 금속 표면, 플라스틱 표면, 종이 표면, 페인트 표면, 음식류, 식물성 기름, 세제류, 석유계 탄화수소에 혈액 20 µL을 남긴 후 AHP를 처리하였다. 이 혈액을 505 nm 광원을 비추며 오렌지색 필터를 통해 관찰 한 결과 모든 물질에서 위양성 혹은 위음성 반응이 관찰되지 않았다. 그러나 polyethylene terephthalate 표면, polyvinylchloride 표면, 일부 페인트 표면, 음식류는 AHP를 처리한 혈액 관찰 조건에서 자체 광발광을 나타내 혈액 관찰을 방해한다는 점을 확인할 수 있었다.

• 분석과학
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• 제37권1호
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• pp.47-62
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• 2024

Abu Gurdi area is located in the South-eastern Desert of Egypt which considered as volcanic massive sulfide deposits (VMS). The present work aims at investigating the ore mineralogy of Abu Gurdi region in addition to the effectiveness of the hydrometallurgical route for processing these ores using alkaline leaching for the extraction of Zn, Cu, and Pb in the presence of hydrogen peroxide, has been investigated. The factors affecting the efficiency of the alkaline leaching of the used ore including the reagent composition, reagent concentration, leaching temperature, leaching time, and Solid /Liquid ratio, have been investigated. It was noted that the sulfide mineralization consists mainly of chalcopyrite, sphalerite, pyrite, galena and bornite. Gold is detected as rare, disseminated crystals within the gangue minerals. Under supergene conditions, secondary copper minerals (covellite, malachite, chrysocolla and atacamite) were formed. The maximum dissolution efficiencies of Cu, Zn, and Pb at the optimum leaching conditions i.e., 250 g/L NaCO₃ - NaHCO₃ alkali concentration, for 3 hr., at 250 ℃, and 1/5 Solid/liquid (S/L) ratio, were 99.48 %, 96.70 % and 99.11 %, respectively. An apparent activation energy for Zn, Cu and Pb dissolution were 21.599, 21.779 and 23.761 kJ.mol^-1, respectively, which were between those of a typical diffusion-controlled process and a chemical reaction-controlled process. Hence, the diffusion of the solid product layer contributed more than the chemical reaction to control the rate of the leaching process. High pure Cu(OH)₂, Pb(OH)₂, and ZnCl₂ were obtained from the finally obtained leach liquor at the optimum leaching conditions by precipitation at different pH. Finally, highly pure Au metal was separated from the mineralized massive sulfide via using adsorption method.

• 한국가축번식학회지
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• 제9권2호
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• pp.133-139
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• 1985

An immunoassay may be defined as an analytical procedure involving the competitive reaction between a limiting concentration of specific antibody and two populations of antigen, one of which is labelled or immobillized. The advent of immunoassay has revolutionised our knowledge of reproductive physiology and the practice of veterinary and clinical medicine. Radioimmunoassay (RIA) was the first of these methods to be developed, which meausred the analyte with good sensitivity, accuracy and precision (1,2). The essential components of RIA are:-(i) a limited concentration of antibodies, (ii) a reference preparation, and (iii) an antigen labelled with a radioisotope (usually tritium or iodine-125). Most procedures invelove isolating the antibody-bound fraction and measuring the amount of labelled antigen. Good facilities are available for scintilltion counting, data reduction nd statistical analysis. RIA is undergoing refinement through:-(i) the introduction of new techniques to separate the antibody-bound and free fractions which minimize the misclassification of labelled antigen into these compartments, and the amount of non-specfic binding. (3), (ii) the development of non-extration for the measurement of haptens (4), (iii) the determination of a, pp.rent free (i.e. non-protein bound) analytes (5), and (iv) the use of monoclonal antibodies(6). In 1968, Miles and Hales introduced in important new type of immunoassay which they termed immunora-diometric assay (IRMA) based on t도 use of isotopically labelled specific antibodies(7) in a move from limited to excess reagent systems. The concept of two-site IRMAs (with a capture antibody on a solid-phase, and a second labelled antibody to a different antigenic determinant of the analyte) has enabled the development of more sensitive and less-time consuming methods for the measurement of protein hormones ovar wide concentration of analyte (8). The increasing use of isotopic methos for diverse a, pp.ications has exposed several problems. For example, the radioactive half-life and radiolysis of the labelled reagent limits assay sensitivity and imposes a time limit on the usefulness of a kit. In addition, the potential health hazards associated with the use and disposal of radioactive cmpounds and the solvents and photofluors necessary for liquid scientillation counting are incompatable with the development of extra-laboratory tests. To date, the most practical alternative labels to radioisotopes, for the measurement of analytes in a concentration > 1 ng/ml, are erythrocytes, polystyrene particiles, gold sols, dyes and enzymes or cofactors with a visual or colorimetric end-point(9). Increased sensitivity to<1 pg/ml may be obtained with fluorescent and chemiluminescent labels, or enzymes with a fluorometric, chemiluminometric or bioluminometric end-point. The sensitivity of any immunoassay or immunometric assay depends on the affinity of the antibody-antigen reaction, the specific activity of the label, the precision with which the reagents are manipulated and the nonspecific background signal (10). The sensitivity of a limited reagent system for the measurement of haptens or proteins is mainly dependent upon the affinity of the antibodies and the smalleest amount of reagent that may be manipulated. Consequently, it is difficult in practice to improve on the sensitivity obtained with iodine-125 as the label. Conversely, with excess reagent systems for the measurement of proteins it is theoretically possible to increase assay sensitivity at least 1000 fold with alternative luminescent labels. To date, a 10-fold improvement has been achieved, and attempts are being made to reduce the influence of other variables on the specific signal from the immunoreaction.

• 한국대기환경학회지
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• 제24권3호
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• pp.357-366
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• 2008

In this study, the analytical performance of trimethylamine (TMA) were investigated with respect to headspace-solid phase microextraction (HS-SPME) method. In order to induce the elution of aqueous TMA to headspace, NaOH was added as a decomposition reagent to aqueous TMA standard. By controlling the combination of three major variables for TMA extraction, the extent of extraction was compared between the two contrasting conditions for each variable (i.e., reaction time (long (L) vs short (S)), exposure temperature (30 vs $50^{\circ}C$), and exposure time (10 vs 30 min)). The results of this comparative analysis showed that the extraction efficiency for all eight types of HS-SPME combinations decreased on the order: L-30-30>L-50-10>L-30-10>L-50-30>S-30-30>S-50-30>S-50-10>S-30-10. The effect of reaction time appeared to exert significant influences on the relative recovery rate of HS-SPME at 90% confidence level. However, the effects of exposure temperature or exposure time were not so significant as reaction time. When the recovery rate of HS-SPME is compared against the direct injection of liquid standard into GC injector, it recorded as 2%. According to this comparative study, the reaction conditions for HS-SPME application can exert significant influences on the analysis of TMA.

• 분석과학
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• 제35권5호
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• pp.218-227
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• 2022

A simple and fast throughput flow injection (FI) system with a merging-zone technique was designed to determine ferrous and ferric in an aqueous solution. The method is based on the direct reaction of ferrous with a Bathophenanthroline reagent (Bphen) in acidic media. The forming red complex absorbs light at 533 nm. All conditions of the flow injection system were investigated. The analytical curve of ferrous was linear in the range of 0.07 to 4 mg/L with an r² value of 0.9968. The detection and quantification limits were 0.02 and 0.04 mg/L, respectively. The molar absorptivity and Sandell's sensitivity were 4.0577 × 10⁶ L/mol cm and 25 × 10^-5 ㎍/cm², respectively. The homemade valve was low-cost with high repeatability (n = 7) at an RSD of 1.26 % and zero dead volume. The values of the dispersion coefficient were 2.318, 2.022, and 1.636 for the concentrations of 0.2, 1, and 3 mg/L, respectively. The analysis throughput of the designed flow injection unit was 57 sample per hour.

• 분석과학
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• 제27권3호
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• pp.161-166
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• 2014

국가공정서 중 하나인 대한민국약전외의약품기준에는 세프록사딘 캡슐의 정량법으로 유해시약인 사염화탄소를 사용하는 산화환원분석법이 수재되어 있다. 세프록사딘 캡슐의 환경 친화적인 대체 시험법으로 보다 안전하고 효율적인 친환경용매를 사용하는 HPLC 분석법을 개발하고, 이를 검증하였다. 직선성은 상관계수($r^2$)가 0.999이상으로 우수하였다. 일내 정밀도는 상대표준편차 0.30~0.69%, 일간 정밀도는 0.47~0.82%로, 회수율은 100.20~100.56%로 나타났다. 개발한 시험법을 이용하여 시중 유통 중인 세프록사딘 캡슐 중 세프록사딘의 함량측정에 응용하였다. 개발된 시험법은 대한민국약전외의약품기준의 개정에 기여가 될 것이다.

• 분석과학
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• 제31권5호
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• pp.195-200
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• 2018

연구자들은 지문 증강 기법에 대한 효과성을 비교하기 위하여 시각적인 판단기준을 이용해왔다. 그러나 시각적인 판단기준은 연구자의 주관적 판단이기 때문에 편향이 생길 수 있다. 따라서 많은 연구자들은 Contrast Index를 이용하여 지문 증강 기법에 대해 객관적인 판단을 하고자 하였다. 하지만 선행연구에서는 잉크지문 또는 정색반응을 통해 현출한 지문에서만 Contrast Index를 검증했다는 한계가 있다. 따라서 본 연구에서는 Contrast Index를 이용하여 표준지문의 농담에 따라 색지별 형광지문의 증강 정도를 비교하였다. Contrast Index의 값은 표준지문의 농담, 배경의 색, 사용 시약 및 광원에 따라 같은 표준지문을 이용하였음에도 각기 다른 값을 나타내었고, 수치 비교를 통하여 배경의 색, 사용 시약 및 광원에 따른 형광지문의 증강 정도를 비교할 수 있었다. 시각적 평가기준을 이용하였을 때에는 시약과 광원에 상관없이 같은 최고점의 점수를 얻은 것과 달리 Contrast Index값을 이용한 본 연구에서는 좀 더 세세한 점수 비교를 할 수 있었다. 결론적으로 Contrast Index를 이용하여 형광시약의 증강 정도를 비교한다면 배경색에 따라 광원과 시약을 선택하는 판단 근거로 사용할 수 있음을 확인하였다.

• 분석과학
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• 제31권1호
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• pp.47-56
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• 2018

사건 현장에 남겨진 혈흔을 찾는 것은 사건을 재구성하거나 해결하기 위해서 매우 중요하다. 사건현장에서 사용할 수 있는 수많은 시약들이 개발되었지만, 루미놀이 가장 대표적인 시약이라고 할 수 있다. 최근에는 블루스타라는 시약이 주로 사용되고 있지만, 가격이 비싸고 시약을 제조한 후 보관이 불가능하다는 단점이 있다. 본 연구에서는 블루스타 수준의 발광강도를 유지하면서 제조 후 장시간 보관할 수 있는 새로운 루미놀 시약을 개발하고자 했다. 루미놀은 알칼리 수용액에서 잘 녹기 때문에, 시약을 제조할 때 수산화나트륨의 사용은 과산화수소의 분해를 촉진시킬 수 있다. 루미놀 시약을 제조할 때 과산화수소 안정화제로 황산마그네슘, 규산나트륨, 삼인산칼륨을 농도별로 첨가한 후, 혈흔과 반응할 때 시약의 발광강도 및 보관기간에 미치는 영향을 확인했다. 과산화수소 안정화제 첨가는 발광강도에 별다른 영향을 주지 않았고, 보관 중 루미놀 시약의 pH를 일정하게 유지시켜 줌으로서 시약의 보관기간을 크게 늘려줬다. 과산화수소 안정화제로 황산마그네슘이 가장 적절하였다. 과산화수소 대신 과붕산나트륨을 산화제로 사용했을 경우, 희석 혈흔에 대한 민감도와 발광강도에 큰 변화는 없었지만 제조 후 보관기간이 단축되었다. 그렇지만, 혈흔과 반응한 후 혼합액의 pH 상승 폭이 과산화수소로 제조한 시약보다 줄어들었다.