Nothing Special   »   [go: up one dir, main page]

JP2013002817A - Method for detecting residual agricultural chemical and surface plasmon resonance sensor - Google Patents

Method for detecting residual agricultural chemical and surface plasmon resonance sensor Download PDF

Info

Publication number
JP2013002817A
JP2013002817A JP2011130656A JP2011130656A JP2013002817A JP 2013002817 A JP2013002817 A JP 2013002817A JP 2011130656 A JP2011130656 A JP 2011130656A JP 2011130656 A JP2011130656 A JP 2011130656A JP 2013002817 A JP2013002817 A JP 2013002817A
Authority
JP
Japan
Prior art keywords
molecular weight
plasmon resonance
surface plasmon
compound
thiol compound
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2011130656A
Other languages
Japanese (ja)
Inventor
Takeshi Onodera
武 小野寺
Masaaki Habara
正秋 羽原
Kiyoshi Toko
潔 都甲
Kaoru Umino
薫 海野
Naoki Mine
直樹 峯
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kyushu University NUC
Intelligent Sensor Technology Inc
Original Assignee
Kyushu University NUC
Intelligent Sensor Technology Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kyushu University NUC, Intelligent Sensor Technology Inc filed Critical Kyushu University NUC
Priority to JP2011130656A priority Critical patent/JP2013002817A/en
Publication of JP2013002817A publication Critical patent/JP2013002817A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a method for detecting a wide variety of residual agricultural chemicals having an auxiliary agent such as nonionic and anionic surfactant.SOLUTION: A method for detecting the concentration of residual agricultural chemicals includes forming a self-organized monomolecular film 15 on the surface of a surface plasmon resonance sensor using a thiol compound having an alkyl chain, flowing a test solution containing a residual agricultural chemical with a surfactant as auxiliary agent in contact with the film 15 so as to change the resonance angle, and detecting the agricultural chemical concentration in the test solution on the basis of the amount of change in the resonance angle. A compound having a carbon chain of 11 or more is used as the thiol compound.

Description

本発明は、農産物製品の残留農薬を、広範な農薬種類に対して高感度に検出するための技術に関する。   The present invention relates to a technique for detecting a residual pesticide in agricultural products with high sensitivity for a wide variety of pesticide types.

平成15年の食品衛生法の改正により、一定量以上の農薬等が残留する食品の販売等を禁止するポジティブリスト制度が導入され、残留農薬の基準値がない農薬には、一律0.01ppmの基準値が設定された。   A revision of the Food Sanitation Law in 2003 introduced a positive list system that prohibits the sale of foods with a certain amount or more of pesticides remaining. A reference value has been set.

その結果、年間200万件を超える検査が行われているが、検査に指定されている公定法では、ガスクロマトグラフィー質量分析計などの分析装置が用いられるため、分析時間(コスト)の削減が課題となっている。   As a result, more than 2 million inspections are conducted annually, but the official method specified for the inspection uses an analyzer such as a gas chromatography mass spectrometer, so the analysis time (cost) can be reduced. It has become a challenge.

その一つの解決策として、本願出願人らは、脂質高分子膜を用いて、市販農薬に助剤として使用されている界面活性剤を検出することで、間接的に残留農薬のスクリーニングを行うための測定手法を提案している(特許文献1)。   As one solution, the present applicants use a lipid polymer membrane to detect a surfactant used as an auxiliary agent for commercially available pesticides, thereby indirectly screening for residual pesticides. Has been proposed (Patent Document 1).

特開2011−007725号公報JP 2011-007725 A

しかしながら、上記脂質高分子膜を用いた検出方法では、農薬に助剤として用いられる界面活性剤のうち、非イオン性の界面活性剤の検出が難しく、検査できる農薬の種類の範囲が全体の70%程度に限られるという問題があった。   However, in the detection method using the lipid polymer membrane, it is difficult to detect a nonionic surfactant among surfactants used as an auxiliary agent for agricultural chemicals, and the range of the types of agricultural chemicals that can be inspected is 70%. There was a problem that it was limited to about%.

本発明は、この問題を解決し、非イオン性および陰イオン性の界面活性剤を助剤とする広範な残留農薬の検知が可能な残留農薬検出方法および表面プラズモン共鳴センサを提供することを目的としている。   An object of the present invention is to solve this problem and to provide a residual pesticide detection method and a surface plasmon resonance sensor capable of detecting a wide range of residual pesticides using nonionic and anionic surfactants as auxiliary agents. It is said.

前記目的を達成するために、本発明の請求項1記載の残留農薬検出方法は、
表面プラズモン共鳴センサの表面に、アルキル鎖を持つチオール化合物を用いて自己組織化単分子膜を形成し、界面活性剤を助剤とする残留農薬を含む被検査溶液を前記自己組織化単分子膜に触れるように流して共鳴角を変化させ、該共鳴角の変化量に基づいて前記被検査溶液中の農薬濃度を検出する残留農薬検出方法であって、
前記チオール化合物として、炭素鎖が11以上の化合物を用いたことを特徴とする。
In order to achieve the object, a method for detecting a residual pesticide according to claim 1 of the present invention comprises:
A self-assembled monolayer is formed on the surface of the surface plasmon resonance sensor using a thiol compound having an alkyl chain, and the solution to be inspected containing a residual agricultural chemical using a surfactant as an auxiliary agent is used as the self-assembled monolayer. A residual agrochemical detection method for detecting the concentration of agrochemical in the solution to be inspected based on the amount of change in the resonance angle,
A compound having 11 or more carbon chains is used as the thiol compound.

本発明の請求項2の残留農薬検出方法は、請求項1記載の残留農薬検出方法において、
助剤として陰イオン性の界面活性剤が含まれている被検査溶液に対して、
前記チオール化合物として、末端に四級アンモニウムカチオンを有する化合物を用いたことを特徴とする。
The method for detecting pesticide residues according to claim 2 of the present invention is the method for detecting pesticide residues according to claim 1,
For a solution to be tested that contains an anionic surfactant as an auxiliary,
A compound having a quaternary ammonium cation at the terminal is used as the thiol compound.

本発明の請求項3の残留農薬検出方法は、請求項2記載の残留農薬検出方法において、
陰イオン性の界面活性剤が助剤として含まれている被検査溶液に対して、
前記チオール化合物として、
TMA N,N,N-trimethyl-(mercaptoundecyl) ammonium chloride 分子量281.93
を用いたことを特徴とする。
The method for detecting pesticide residues according to claim 3 of the present invention is the method for detecting pesticide residues according to claim 2,
For a solution to be tested that contains an anionic surfactant as an auxiliary agent,
As the thiol compound,
TMA N, N, N-trimethyl- (mercaptoundecyl) ammonium chloride Molecular weight 281.93
It is characterized by using.

本発明の請求項4の残留農薬検出方法は、請求項1記載の残留農薬検出方法において、
非イオン性の界面活性剤が助剤として含まれている被検査溶液に対して、
前記チオール化合物として、
C11 1-Undecanethiol 分子量188.37
C18 1-Octadecanethiol 分子量286.56
C20 Eicosane thiol 分子量314.62
のいずれかを用いていることを特徴とする。
The method for detecting pesticide residues according to claim 4 of the present invention is the method for detecting pesticide residues according to claim 1,
For a solution to be tested that contains a nonionic surfactant as an auxiliary agent,
As the thiol compound,
C11 1-Undecanethiol Molecular weight 188.37
C18 1-Octadecanethiol Molecular weight 286.56
C20 Eicosane thiol Molecular weight 314.62
Any of the above is used.

また、本発明の請求項5の表面プラズモン共鳴センサは、
センサ表面に、アルキル鎖を持つチオール化合物による自己組織化単分子膜が形成された表面プラズモン共鳴センサにおいて、
前記チオール化合物は、炭素鎖が11以上の化合物であることを特徴とする。
The surface plasmon resonance sensor according to claim 5 of the present invention is
In a surface plasmon resonance sensor in which a self-assembled monomolecular film formed of a thiol compound having an alkyl chain is formed on the sensor surface,
The thiol compound is a compound having 11 or more carbon chains.

また、本発明の請求項6の表面プラズモン共鳴センサは、請求項5記載の表面プラズモン共鳴センサにおいて、
前記チオール化合物は、末端に四級アンモニウムカチオンを有する化合物であることを特徴とする。
The surface plasmon resonance sensor according to claim 6 of the present invention is the surface plasmon resonance sensor according to claim 5,
The thiol compound is a compound having a quaternary ammonium cation at a terminal.

また、本発明の請求項7の表面プラズモン共鳴センサは、請求項6記載の表面プラズモン共鳴センサにおいて、
前記チオール化合物が、
TMA N,N,N-trimethyl-(mercaptoundecyl) ammonium chloride
分子量281.93
であることを特徴とする。
The surface plasmon resonance sensor according to claim 7 of the present invention is the surface plasmon resonance sensor according to claim 6,
The thiol compound is
TMA N, N, N-trimethyl- (mercaptoundecyl) ammonium chloride
Molecular weight 281.93
It is characterized by being.

また、本発明の請求項8の表面プラズモン共鳴センサは、請求項5記載の表面プラズモン共鳴センサにおいて、
前記チオール化合物が、
C11 1-Undecanethiol 分子量188.37
C18 1-Octadecanethiol 分子量286.56
C20 Eicosane thiol 分子量314.62
のいずれかであることを特徴とする。
The surface plasmon resonance sensor according to claim 8 of the present invention is the surface plasmon resonance sensor according to claim 5,
The thiol compound is
C11 1-Undecanethiol Molecular weight 188.37
C18 1-Octadecanethiol Molecular weight 286.56
C20 Eicosane thiol Molecular weight 314.62
It is either of these.

以上のように、本発明では、残留農薬に助剤として含まれる界面活性剤を、表面プラズモン共鳴センサで検出できるように、そのセンサ表面に、アルキル鎖を持つチオール化合物によって形成する自己組織化単分子膜として、炭素鎖の長さと界面活性剤の吸着性の関係を調べた結果から、炭素鎖長11以上のチオール化合物は、非イオン性界面活性剤に対して高感度な応答を示すことを確認しており、この化合物を用いることで、従来検出できなかった非イオン性界面活性剤および陰イオン性界面活性剤を助剤とする広範な農薬の高感度検知が可能となる。   As described above, in the present invention, the surfactant contained as an auxiliary agent in the residual pesticide is a self-assembled simple substance formed on the sensor surface by a thiol compound having an alkyl chain so that the surface plasmon resonance sensor can detect the surfactant. From the results of investigating the relationship between carbon chain length and surfactant adsorptivity as a molecular film, thiol compounds having a carbon chain length of 11 or more show a highly sensitive response to nonionic surfactants. It has been confirmed that by using this compound, it is possible to detect a wide range of pesticides using a nonionic surfactant and an anionic surfactant, which could not be detected in the past, as auxiliary agents.

また、特に、陰イオン性界面活性剤に対しては、末端に四級アンモニウムカチオンを有するTMAに代表される化合物を用いることで、極めて高感度な検出が可能となる。   In particular, for an anionic surfactant, detection with extremely high sensitivity is possible by using a compound represented by TMA having a quaternary ammonium cation at the terminal.

また、非イオン性界面活性剤に対しては、
C11 1-Undecanethiol 分子量188.37
C18 1-Octadecanethiol 分子量286.56
C20 Eicosane thiol 分子量314.62
の化合物を用いることで高感度な検出が可能となり、さらに、その炭素鎖が最長のC20が特に高感度検出可能である。
For nonionic surfactants,
C11 1-Undecanethiol Molecular weight 188.37
C18 1-Octadecanethiol Molecular weight 286.56
C20 Eicosane thiol Molecular weight 314.62
By using this compound, highly sensitive detection is possible, and C20 having the longest carbon chain can be detected with particularly high sensitivity.

表面プラズモン共鳴センサの構造の模式図Schematic diagram of the structure of a surface plasmon resonance sensor 陰イオン性界面活性剤SDSに対するTMAセンサ膜の応答特性Response characteristics of TMA sensor membrane to anionic surfactant SDS 陰イオン性界面活性剤SDSの各センサ膜への吸着特性Adsorption characteristics of anionic surfactant SDS on each sensor membrane 陰イオン性界面活性剤SDSのC20〜C11センサ膜への吸着特性Adsorption characteristics of anionic surfactant SDS on C20-C11 sensor membrane 非イオン性界面活性剤Brij58に対するC20センサ膜の応答特性Response characteristics of C20 sensor film to nonionic surfactant Brij58 非イオン性界面活性剤Brij58のC20およびC18センサ膜への吸着特性Adsorption characteristics of nonionic surfactant Brij58 on C20 and C18 sensor membranes 非イオン性界面活性剤Brij58のC20〜C11センサ膜への吸着特性Adsorption characteristics of nonionic surfactant Brij58 on C20-C11 sensor membrane 農薬原体およびSDS混合物に対するTMAセンサ膜の応答特性Response characteristics of TMA sensor membrane to pesticide active substance and SDS mixture 農薬原体およびSDS混合物に対するC20センサ膜の応答特性Response characteristics of C20 sensor membrane to pesticide bulk and SDS mixture

以下、図面に基づいて本発明の実施の形態を説明する。
本願発明者らは、一種の高感度な屈折率計である表面プラズモン共鳴測定装置を用いた残留農薬検知の可能性を確かめるべく、種々の実験を行った。以下、その実験方法および測定結果について説明する。
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The inventors of the present application conducted various experiments to confirm the possibility of residual pesticide detection using a surface plasmon resonance measuring apparatus which is a kind of highly sensitive refractometer. The experimental method and measurement results will be described below.

(実験方法)
(A)測定系
測定には、表面プラズモン共鳴(以下、SPRと記す)センサを用いている。
このSPRセンサは、表面プラズモン共鳴現象を利用して高感度に化学物質などを検出することが可能なセンサであり、具体的には図1の構成を有している。
(experimental method)
(A) Measurement system A surface plasmon resonance (hereinafter referred to as SPR) sensor is used for measurement.
This SPR sensor is a sensor capable of detecting a chemical substance or the like with high sensitivity using a surface plasmon resonance phenomenon, and specifically has the configuration shown in FIG.

即ち、プリズム11の表面側の金薄膜12に対してプリズム11側から発光器(LED等)13から光を照射し、その反射光を受光器14で受けて強度を測定する。この時、金薄膜12の表面では、エバネッセント波がしみ出す。金薄膜12表面のプラズモンとエバネッセント波の波数が一致したとき共鳴が起こり、光のエネルギーが共鳴に使われるため、反射光強度は減少する。この反射光強度が最小となる入射角度を共鳴角と呼ぶ。共鳴角は金薄膜12表面の屈折率に依存して変化し、その屈折率は金薄膜12表面の質量変化に応じて変化する。   That is, the gold thin film 12 on the surface side of the prism 11 is irradiated with light from the light emitter (LED or the like) 13 from the prism 11 side, and the reflected light is received by the light receiver 14 to measure the intensity. At this time, evanescent waves ooze out on the surface of the gold thin film 12. Resonance occurs when the wave number of the plasmon on the surface of the gold thin film 12 and the evanescent wave coincide with each other, and light energy is used for resonance, so that the reflected light intensity decreases. The incident angle that minimizes the reflected light intensity is called the resonance angle. The resonance angle changes depending on the refractive index of the gold thin film 12 surface, and the refractive index changes according to the mass change of the gold thin film 12 surface.

そして、金薄膜12の表面には、測定対象物質に選択的に結合するような化合物(自己組織化単分子膜SAM)の膜15が形成されており、被測定液をこの膜15に触れるように流動させることで、被測定液中の検出対象物質を膜15の表面に結合させて質量増加させ、共鳴角を変位させる。   A film 15 of a compound (self-assembled monomolecular film SAM) that selectively binds to the measurement target substance is formed on the surface of the gold thin film 12 so that the liquid to be measured touches the film 15. , The substance to be detected in the liquid to be measured is bound to the surface of the film 15 to increase its mass, and the resonance angle is displaced.

本発明の実験では、前記SPRセンサを用いた装置として、GEヘルスケアバイオサイエンス社製のBiacore
J(登録商標)を使用した。またセンサに装着する金薄膜としてGEヘルスケアバイオサイエンス社製のSIA Kitのものを用いた。ランニングバッファーとして、Phosphate-buffered saline(PBS; 10mM phosphate, 140mM NaCl, pH 7.4)を用いた。ランニングバッファーは使用前にフィルターでろ過し、十分脱気を行い用いた。流速は約30μl/minに設定して、測定を行った。
In the experiment of the present invention, as a device using the SPR sensor, Biacore manufactured by GE Healthcare Biosciences is used.
J (registered trademark) was used. In addition, a SIA Kit manufactured by GE Healthcare Biosciences was used as a thin gold film to be attached to the sensor. As a running buffer, Phosphate-buffered saline (PBS; 10 mM phosphate, 140 mM NaCl, pH 7.4) was used. The running buffer was filtered before use and sufficiently deaerated before use. The flow rate was set to about 30 μl / min and the measurement was performed.

(B)試薬
測定対象として、以下の陰イオン性界面活性剤のドデシル硫酸ナトリウム(SDS)と、非イオン性界面活性剤のポリオキシエチレン(20)セチルエーテル(Brij58)を用いた。
(a1)ドデシル硫酸ナトリウム(SDS) (和光純薬工業株式会社) 分子量288.38cmc 8.1mM
(a2)ポリオキシエチレン(20)セチルエーテル(Brij58) (和光純薬工業株式会社) 分子量1124cmc 0.08mM
(B) Reagents The following anionic surfactant sodium dodecyl sulfate (SDS) and nonionic surfactant polyoxyethylene (20) cetyl ether (Brij58) were used as measurement targets.
(A1) Sodium dodecyl sulfate (SDS) (Wako Pure Chemical Industries, Ltd.) Molecular weight 288.38cmc 8.1mM
(A2) Polyoxyethylene (20) cetyl ether (Brij58) (Wako Pure Chemical Industries, Ltd.) Molecular weight 1124cmc 0.08mM

また、農薬として、以下のイマザリルおよびグリホサートを選んだ。
(b1)イマザリル C1414Cl20(和光純薬工業株式会社) 分子量297.18
(b2)グリホサート HOCCHNHCHP(O)(OH) (和光純薬工業株式会社) 分子量169.07
In addition, the following imazaril and glyphosate were selected as pesticides.
(B1) Imazaril C 14 H 14 Cl 2 N 20 (Wako Pure Chemical Industries, Ltd.) Molecular weight 297.18
(B2) Glyphosate HO 2 CCH 2 NHCH 2 P (O) (OH) 2 (Wako Pure Chemical Industries, Ltd.) Molecular weight 169.07

表面の修飾試薬(SAM)としては、以下の4種類のチオール化合物、1-Undecanethiol、1-Octadecanethiol、Eicosane thiolおよびN,N,N-trimethyl-(mercaptoundecyl) ammonium chloride(TMA)を用いた。   The following four thiol compounds, 1-Undecanethiol, 1-Octadecanethiol, Eicosane thiol, and N, N, N-trimethyl- (mercaptoundecyl) ammonium chloride (TMA) were used as the surface modification reagent (SAM).

(c1)C11 1-Undecanethiol (化学式HS-(CH2)10-CH3)(東京化成工業株式会社) 分子量188.37
(c2)C18 1-Octadecanethiol (化学式HS-(CH2)17-CH3)(東京化成工業株式会社) 分子量286.56
(c3)C20 Eicosane thiol (化学式HS-(CH2)19-CH3)(Endeavour Speciality Chemicals社) 分子量314.62
(c4)TMA N,N,N-trimethyl-(mercaptoundecyl) ammonium chloride (化学式HS-(CH2)11NMe3)(Prochimia Surfaces社) 分子量281.93
(C1) C11 1-Undecanethiol (Chemical formula HS- (CH 2 ) 10 -CH 3 ) (Tokyo Chemical Industry Co., Ltd.) Molecular weight 188.37
(C2) C18 1-Octadecanethiol (Chemical formula HS- (CH 2 ) 17 -CH 3 ) (Tokyo Chemical Industry Co., Ltd.) Molecular weight 286.56
(C3) C20 Eicosane thiol (Formula HS- (CH 2 ) 19 -CH 3 ) (Endeavor Specialty Chemicals) Molecular weight 314.62
(C4) TMA N, N, N-trimethyl- (mercaptoundecyl) ammonium chloride (chemical formula HS- (CH 2 ) 11 NMe 3 ) (Prochimia Surfaces) Molecular weight 281.93

また、比較のために、OH末端の試薬として、
(c5)OH 11-mercapto-1-undecanol (化学式HS-(CH2)11-OH)(ALDRICH) 分子量204.37
を用いている。
For comparison, as an OH-terminated reagent,
(C5) OH 11-mercapto-1-undecanol (Formula HS- (CH 2 ) 11 -OH) (ALDRICH) Molecular weight 204.37
Is used.

(C)センサ表面の作製
金薄膜として、GEヘルスケアバイオサイエンス社製のSIA Kit Auに含まれるSensor Chip Auを用いた。
(C) Preparation of sensor surface Sensor Chip Au contained in SIA Kit Au manufactured by GE Healthcare Biosciences was used as the gold thin film.

また、金薄膜チップをアセトン、エタノール、2-プロパノールに浸漬し、それぞれ10、2、2分間超音波洗浄を行った。その後、SC1洗浄液(アンモニア水、過酸化水素水、純水を1:1:5で混合した溶液)に浸漬し、ホットプレートで20分間90度に加熱した。その後、金薄膜チップを超純水でリンスした。   Further, the gold thin film chip was immersed in acetone, ethanol, and 2-propanol, and subjected to ultrasonic cleaning for 10, 2 and 2 minutes, respectively. Then, it was immersed in SC1 washing | cleaning liquid (The solution which mixed ammonia water, hydrogen peroxide water, and pure water 1: 1: 5), and it heated at 90 degree | times for 20 minutes with the hotplate. Thereafter, the gold thin film chip was rinsed with ultrapure water.

続いて、洗浄後の金チップを、1mMのSAM溶液(溶媒 エタノール)に24時間浸漬し、SAMs(自己組織化単分子膜)を形成した。SAMs形成後は、修飾試薬エタノール溶液から取り出し、金薄膜の表面に非特異的吸着している修飾試薬を除去するため、エタノールに浸漬し、超音波洗浄機で3分間洗浄した。その後、エタノールから取り出した金薄膜チップを超純水でリンスし、窒素ブローで乾燥させた。   Subsequently, the washed gold chip was immersed in a 1 mM SAM solution (solvent ethanol) for 24 hours to form SAMs (self-assembled monolayers). After the SAMs were formed, they were taken out from the modifying reagent ethanol solution, immersed in ethanol and washed with an ultrasonic cleaner for 3 minutes in order to remove the modifying reagent adsorbed nonspecifically on the surface of the gold thin film. Thereafter, the gold thin film chip taken out from ethanol was rinsed with ultrapure water and dried by nitrogen blowing.

(D)試薬の調整
(d1)ストック溶液の調整
100ppmのイマザリル、グリホサート、SDS、Brij58 in PBS溶液を用意した。イマザリルはアセトンに溶かした後、PBS溶液を加え、100ppmイマザリル PBS溶液を作成した。
(D) Preparation of reagent (d1) Preparation of stock solution A 100 ppm imazalil, glyphosate, SDS, Brij58 in PBS solution was prepared. Imazalil was dissolved in acetone, and then a PBS solution was added to prepare a 100 ppm imazalyl PBS solution.

(d2)界面活性剤溶液
100ppmの界面活性剤 PBS溶液をPBSで希釈し、各濃度の界面活性剤 PBS溶液を作成した。
(D2) Surfactant solution 100 ppm of surfactant PBS solution was diluted with PBS to prepare surfactant PBS solutions of various concentrations.

(d3)農薬溶液
100ppmの農薬 PBS溶液をPBSで希釈し、各濃度の農薬 PBS溶液を作成した。
(D3) Pesticide solution 100 ppm pesticide PBS solution was diluted with PBS to prepare each concentration of pesticide PBS solution.

(d4)農薬+界面活性剤溶液
100ppmの界面活性剤 PBS溶液と100ppmの農薬 PBS溶液を1:1の割合で混合し、さらにPBSにより希釈し、界面活性剤と農薬がそれぞれ30、100、300、1000ppbの各濃度となる農薬+界面活性剤 PBS溶液を作成した。
(D4) Pesticide + surfactant solution 100 ppm surfactant PBS solution and 100 ppm pesticide PBS solution is mixed at a ratio of 1: 1, further diluted with PBS, and surfactant and pesticide are 30, 100 and 300, respectively. A pesticide + surfactant PBS solution having a concentration of 1000 ppb was prepared.

(E)測定結果
(E−1)SAMsへのSDS吸着の測定
センサの金薄膜表面に前記4種類のチオール化合物(c1)〜(c4)と(c5)のOHとを修飾したセンサを用いて、SDS吸着の測定を行った。SPR装置に緩衝液を流し、各濃度のSDS溶液を2分間添加した。測定は3回行った。
(E) Measurement result (E-1) Measurement of SDS adsorption to SAMs Using a sensor in which the four kinds of thiol compounds (c1) to (c4) and (OH) of (c5) are modified on the gold thin film surface of the sensor. SDS adsorption was measured. The buffer solution was passed through the SPR device, and each concentration of SDS solution was added for 2 minutes. The measurement was performed 3 times.

図2は、チオール化合物として(c4)のTMAセンサ表面を用いたSPR測定のセンサグラムである。この図2の測定結果において、1000ppbのSDS溶液の応答を見ると、溶液流通開始後からTMAセンサ表面にSDSが吸着することによりセンサ応答が立ち上がり、流通終了と同時にベースライン付近まで戻っていることがわかる。0〜30ppbの応答に違いは見られないが、100ppb以上では30ppb以下との差がはっきりわかる。なお、単位RU(Resonace Unit)は、共鳴角度0.1°=1000RUに相当する値である。   FIG. 2 is a sensorgram of SPR measurement using the TMA sensor surface of (c4) as a thiol compound. In the measurement result of FIG. 2, when the response of the 1000 ppb SDS solution is seen, the sensor response rises as SDS is adsorbed on the TMA sensor surface after the solution flow starts, and returns to the baseline near the end of the flow. I understand. Although there is no difference in the response from 0 to 30 ppb, the difference from 30 ppb or less is clearly seen at 100 ppb or more. The unit RU (Resonace Unit) is a value corresponding to a resonance angle of 0.1 ° = 1000 RU.

図3は、SAMsへのSDS吸着特性を測定した結果である。この図3の結果から、C11、C18、C20、TMAで表面修飾された各センサいずれについてもSDS濃度に相関する応答が得られており、これらの炭素鎖11以上の4つのチオール化合物に関してSDSの検知が可能である。   FIG. 3 shows the results of measuring the SDS adsorption characteristics to SAMs. From the results shown in FIG. 3, responses correlated with the SDS concentration were obtained for each of the sensors surface-modified with C11, C18, C20, and TMA. SDS of these four thiol compounds having carbon chains of 11 or more was obtained. Detection is possible.

その中で、特に、末端に四級アンモニウムカチオンが導入されているTMAセンサ表面への吸着が一番高く、極めて高感度な検出が可能であることを示している。   Among them, in particular, the adsorption to the surface of the TMA sensor in which a quaternary ammonium cation is introduced at the terminal is the highest, and it is shown that detection with extremely high sensitivity is possible.

なお、サンプル溶液とランニングバッファーの比重の違いから生じるバルク効果(溶媒による屈折率変化)はヘキサエチレングリコール(EG60H) SAMをリファレンスとして用いて差し引いている。低濃度域(10ppm以下)では、バルク効果の影響はほとんどない。ヘキサエチレングリコールSAMに使った試薬は以下の通りである。
EG60H 11-mercaptoundecanol hexaethylenglycol ether
化学式 HS-(CH2)11-(OCH2CH2)-OH (Prochimia Surfaces社) 分子量 468.69
The bulk effect (refractive index change due to the solvent) resulting from the difference in specific gravity between the sample solution and the running buffer is subtracted using hexaethylene glycol (EG60H) SAM as a reference. In the low concentration range (10 ppm or less), there is almost no influence of the bulk effect. The reagents used for hexaethylene glycol SAM are as follows.
EG60H 11-mercaptoundecanol hexaethylenglycol ether
Chemical formula HS- (CH 2) 11 - ( OCH 2 CH 2) -OH (Prochimia Surfaces , Inc.) molecular weight 468.69

ここで、TMAセンサとC11センサの炭素鎖長は同じであるから、C11センサに対して、末端に四級アンモニウムカチオンが導入されている点が異なるTMAセンサが、陰イオン性界面活性剤であるSDSの吸着がより促進されていることが明らかである。また、末端にヒドロキシル基を有するOHセンサには、ほとんど吸着が見られない。   Here, since the carbon chain lengths of the TMA sensor and the C11 sensor are the same, the TMA sensor that is different from the C11 sensor in that a quaternary ammonium cation is introduced at the terminal is an anionic surfactant. It is clear that the adsorption of SDS is further promoted. Moreover, adsorption is hardly seen in the OH sensor which has a hydroxyl group at the terminal.

図4は、図3からC20、C18、C11の各センサの特性を比較するために抜き出したものであり、C18センサ表面とC20センサ表面の特性に大きな違いはないが、低濃度域ではC20センサ表面の方が応答性がよい。また、C11センサ表面とは、10ppm以上の濃度領域で吸着量が明確に異なることがわかる。   FIG. 4 is extracted from FIG. 3 to compare the characteristics of the sensors C20, C18, and C11. There is no significant difference between the characteristics of the C18 sensor surface and the C20 sensor surface. The surface is more responsive. It can also be seen that the adsorption amount is clearly different from the C11 sensor surface in a concentration region of 10 ppm or more.

(E−2)SAMsへのBrij58吸着の測定
センサ表面に、上記(c1)〜(c4)の4種類のチオール化合物を修飾し、SDS吸着の測定を行った。SPR装置に緩衝液を流し、各濃度のBrij58溶液を2分間添加した。測定は3回行った。
(E-2) Measurement of Brij58 adsorption to SAMs The four thiol compounds (c1) to (c4) above were modified on the sensor surface, and SDS adsorption was measured. The buffer solution was passed through the SPR apparatus, and Brij58 solution of each concentration was added for 2 minutes. The measurement was performed 3 times.

図5は、例としてC20センサ表面におけるSPR測定のセンサグラムを示す。この図5から、TMAセンサ表面へのSDS吸着特性と同様に、30ppb以下では応答が見られないが、100ppb以上で、センサグラムの上昇が見られる。   FIG. 5 shows a sensorgram of SPR measurement on the C20 sensor surface as an example. From FIG. 5, as with the SDS adsorption characteristic on the surface of the TMA sensor, no response is observed at 30 ppb or less, but an increase in sensorgram is observed at 100 ppb or more.

図6は、C20センサ表面およびC18センサ表面へのBrij58吸着特性を示すものであり、C18センサとC20センサの特性に大きな違いはないが、図7に示す低濃度域の拡大図ではC20センサの方が応答性がよいことがわかる。   FIG. 6 shows the Brij58 adsorption characteristics to the C20 sensor surface and the C18 sensor surface, and there is no significant difference between the characteristics of the C18 sensor and the C20 sensor, but the enlarged view of the low concentration region shown in FIG. It can be seen that the responsiveness is better.

なお、ここでは、アルキル鎖を持つチオール化合物のうち、炭素鎖11、18、20の化合物について実験しているが、実験結果から非イオン性の界面活性剤Brij58に対しては、炭素鎖が長い程感度が高くなっているので、炭素鎖が20を超えるものがより高い感度をもつことが十分予測されるが、炭素鎖が20を超えるチオール化合物は製造上困難性があり、現状では、非イオン性界面活性剤に対して、C20のセンサが最も適していると認められる。なお、図6の結果は、ヘキサエチレングリコール(EG60H)
SAMをリファレンスとして用いてバルク効果を差し引いている。低濃度域(3ppm以下)では、バルク効果の影響はほとんどない。
Here, among thiol compounds having an alkyl chain, an experiment is performed on compounds of carbon chains 11, 18, and 20. From the experimental results, the carbon chain is longer than the nonionic surfactant Brij58. As the sensitivity is so high, it is sufficiently predicted that those having more than 20 carbon chains have higher sensitivity. However, thiol compounds having more than 20 carbon chains are difficult to manufacture, and currently, For ionic surfactants, a C20 sensor appears to be most suitable. In addition, the result of FIG. 6 is hexaethylene glycol (EG60H).
Bulk effect is subtracted using SAM as a reference. In the low concentration range (3 ppm or less), there is almost no influence of the bulk effect.

(E−3)疑似農薬の測定
図8にTMAセンサ表面における農薬原体および陰イオン性のSDS混合疑似農薬の測定結果、図9にC20センサ表面における農薬原体および非イオン性のBrij58混合疑似農薬の測定結果を示す。
(E-3) Pseudo-pesticide measurement FIG. 8 shows the measurement results of the pesticide active substance and anionic SDS mixed pseudo-pesticide on the surface of the TMA sensor, and FIG. 9 shows the pesticide active substance and non-ionic Brij58 mixed pseudo on the C20 sensor surface. The measurement results of pesticides are shown.

これらの測定結果から、グリホサートおよびイマザリルに対しては、1000ppbまでの濃度範囲ではほとんど応答しておらず、SDSあるいはBrij58との混合溶液では、どちらも応答していることがわかる。つまり、どちらのセンサ表面でも原体のグリホサートおよびイマザリル単体ではセンサ応答がほとんどないが、助剤である界面活性剤のSDSあるいはBrij58が存在するとセンサ応答が得られている。   From these measurement results, it can be seen that glyphosate and imazalil hardly respond in the concentration range up to 1000 ppb, and both respond in the mixed solution with SDS or Brij58. In other words, the sensor glyphosate and imazalil alone have almost no sensor response on either sensor surface, but the sensor response is obtained in the presence of SDS or Brij 58 as an auxiliary agent.

なお、実際には、農薬の原体と助剤の混合比が製品によって決まっているから、助剤である界面活性剤の濃度検知が行えれば、既知の混合比から農薬原体の濃度も推定でき、その推定値が、ある基準値を超える被検査溶液に対してのみ、ガスクロマトグラフィー質量分析計などの分析装置を用いた公定法による分析を行えばよいから、効率的な検査が行える。   Actually, the mixing ratio of the pesticide active ingredient and the auxiliary agent is determined by the product. Efficient inspection can be performed because it is only necessary to perform analysis by an official method using an analyzer such as a gas chromatography mass spectrometer only for a solution to be inspected whose estimated value exceeds a certain reference value. .

(E−4)検出限界
サンプルとして、PBSのみを流した場合(測定回数11回)の平均値と標準偏差σから、検出限界を、
検出限界(RU)=平均値+3.29σ
として求めた。この結果より、SDSの検出限界は15.99RU、Brij58の検出限界は16.31RUとなる。
(E-4) Detection limit From the average value and standard deviation σ when only PBS is flowed as a sample (11 measurement times), the detection limit is
Detection limit (RU) = average value + 3.29σ
As sought. As a result, the detection limit of SDS is 15.99RU, and the detection limit of Brij58 is 16.31RU.

そして、この検出限界における界面活性剤濃度を検量線より求めると、
SDS……50ppb
SDS+グリホサート……90ppb
SDS+イマザリル……60ppb
Brij58……30ppb
Brij58+グリホサート……90ppb
Brij58+イマザリル……90ppb
となり、総じて90ppbの濃度で検出できることがわかる。
And when obtaining the surfactant concentration at this detection limit from the calibration curve,
SDS …… 50ppb
SDS + glyphosate …… 90ppb
SDS + Imazaril ... 60ppb
Brij58 …… 30ppb
Brij58 + glyphosate …… 90ppb
Brij58 + Imazaril ... 90ppb
Thus, it can be seen that detection is possible at a concentration of 90 ppb as a whole.

以上の測定結果から、TMAで代表されるように、末端に四級アンモニウムカチオンを有するチオール化合物によるSAMが好適であり、また、C20〜C11のようなアルカンチオール化合物によるSAMの場合、炭素鎖長が長い程、応答が高いと認められる。   From the above measurement results, as represented by TMA, SAM using a thiol compound having a quaternary ammonium cation at the terminal is suitable, and in the case of SAM using an alkanethiol compound such as C20 to C11, the carbon chain length is The longer it is, the higher the response.

したがって、アニオン性(陰イオン性)界面活性剤の検出には、鎖長が長く(C11以上)、末端に四級アンモニウムカチオンを有するSAMを用いることで、より高感度に界面活性剤および農薬助剤を検出することが可能であり、非イオン性界面活性剤の検出には、炭素鎖が長い(C11以上)ほど高感度な検出が可能であり、これらを使い分けることで80%の農薬の検知が可能となった。   Therefore, for the detection of anionic (anionic) surfactants, a SAM having a long chain length (C11 or more) and having a quaternary ammonium cation at the terminal is used, so that the surfactant and agricultural chemical aid are more sensitive. The longer the carbon chain (C11 or higher), the more sensitive detection is possible for detecting non-ionic surfactants. By using these separately, 80% of pesticides can be detected. Became possible.

11……プリズム、12……金薄膜、13……発光器、14……受光器、15……膜   11 ... Prism, 12 ... Gold thin film, 13 ... Light emitter, 14 ... Light receiver, 15 ... Film

Claims (8)

表面プラズモン共鳴センサの表面に、アルキル鎖を持つチオール化合物を用いて自己組織化単分子膜を形成し、界面活性剤を助剤とする残留農薬を含む被検査溶液を前記自己組織化単分子膜に触れるように流して共鳴角を変化させ、該共鳴角の変化量に基づいて被検査溶液中の農薬濃度を検出する残留農薬検出方法であって、
前記チオール化合物として、炭素鎖が11以上の化合物を用いたことを特徴とする残留農薬検出方法。
A self-assembled monolayer is formed on the surface of the surface plasmon resonance sensor using a thiol compound having an alkyl chain, and the solution to be inspected containing a residual agricultural chemical using a surfactant as an auxiliary agent is used as the self-assembled monolayer. A method for detecting a residual pesticide that detects a concentration of a pesticide in a solution to be inspected based on a change amount of the resonance angle by flowing to touch the
A method for detecting residual agricultural chemicals, wherein a compound having 11 or more carbon chains is used as the thiol compound.
助剤として陰イオン性の界面活性剤が含まれている被検査溶液に対して、
前記チオール化合物として、末端に四級アンモニウムカチオンを有する化合物を用いたことを特徴とする請求項1記載の残留農薬検出方法。
For a solution to be tested that contains an anionic surfactant as an auxiliary,
The method for detecting a residual agricultural chemical according to claim 1, wherein a compound having a quaternary ammonium cation at a terminal is used as the thiol compound.
陰イオン性の界面活性剤が助剤として含まれている被検査溶液に対して、
前記チオール化合物として、
TMA N,N,N-trimethyl-(mercaptoundecyl) ammonium chloride
分子量281.93
を用いたことを特徴とする請求項2記載の残留農薬検出方法。
For a solution to be tested that contains an anionic surfactant as an auxiliary agent,
As the thiol compound,
TMA N, N, N-trimethyl- (mercaptoundecyl) ammonium chloride
Molecular weight 281.93
The method for detecting a residual agricultural chemical according to claim 2, wherein:
非イオン性の界面活性剤が助剤として含まれている被検査溶液に対して、
前記チオール化合物として、
C11 1-Undecanethiol 分子量188.37
C18 1-Octadecanethiol 分子量286.56
C20 Eicosane thiol 分子量314.62
のいずれかを用いていることを特徴とする請求項1記載の残留農薬検出方法。
For a solution to be tested that contains a nonionic surfactant as an auxiliary agent,
As the thiol compound,
C11 1-Undecanethiol Molecular weight 188.37
C18 1-Octadecanethiol Molecular weight 286.56
C20 Eicosane thiol Molecular weight 314.62
Either of these is used, The residual agrochemical detection method of Claim 1 characterized by the above-mentioned.
センサ表面に、アルキル鎖を持つチオール化合物による自己組織化単分子膜が形成された表面プラズモン共鳴センサにおいて、
前記チオール化合物は、炭素鎖が11以上の化合物であることを特徴とする表面プラズモン共鳴センサ。
In a surface plasmon resonance sensor in which a self-assembled monomolecular film formed of a thiol compound having an alkyl chain is formed on the sensor surface,
The surface plasmon resonance sensor, wherein the thiol compound is a compound having 11 or more carbon chains.
前記チオール化合物は、末端に四級アンモニウムカチオンを有する化合物であることを特徴とする請求項5記載の表面プラズモン共鳴センサ。   6. The surface plasmon resonance sensor according to claim 5, wherein the thiol compound is a compound having a quaternary ammonium cation at a terminal. 前記チオール化合物が、
TMA N,N,N-trimethyl-(mercaptoundecyl) ammonium chloride
分子量281.93
であることを特徴とする請求項6記載の表面プラズモン共鳴センサ。
The thiol compound is
TMA N, N, N-trimethyl- (mercaptoundecyl) ammonium chloride
Molecular weight 281.93
The surface plasmon resonance sensor according to claim 6.
前記チオール化合物が、
C11 1-Undecanethiol 分子量188.37
C18 1-Octadecanethiol 分子量286.56
C20 Eicosane thiol 分子量314.62
のいずれかであることを特徴とする請求項5記載の表面プラズモン共鳴センサ。
The thiol compound is
C11 1-Undecanethiol Molecular weight 188.37
C18 1-Octadecanethiol Molecular weight 286.56
C20 Eicosane thiol Molecular weight 314.62
The surface plasmon resonance sensor according to claim 5, wherein the surface plasmon resonance sensor is any one of the following.
JP2011130656A 2011-06-10 2011-06-10 Method for detecting residual agricultural chemical and surface plasmon resonance sensor Pending JP2013002817A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2011130656A JP2013002817A (en) 2011-06-10 2011-06-10 Method for detecting residual agricultural chemical and surface plasmon resonance sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2011130656A JP2013002817A (en) 2011-06-10 2011-06-10 Method for detecting residual agricultural chemical and surface plasmon resonance sensor

Publications (1)

Publication Number Publication Date
JP2013002817A true JP2013002817A (en) 2013-01-07

Family

ID=47671561

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2011130656A Pending JP2013002817A (en) 2011-06-10 2011-06-10 Method for detecting residual agricultural chemical and surface plasmon resonance sensor

Country Status (1)

Country Link
JP (1) JP2013002817A (en)

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10265301A (en) * 1997-03-03 1998-10-06 Rohm & Haas Co Agrochemical composition
JPH116834A (en) * 1997-06-17 1999-01-12 Mitsubishi Chem Corp Sensor chip for biosensor, biosensor and manufacture thereof
JP2002357540A (en) * 2001-05-31 2002-12-13 Suzuki Motor Corp Plasmon sensor and method for measuring using the same
JP2006266746A (en) * 2005-03-22 2006-10-05 Fuji Photo Film Co Ltd Biosensor
JP2007085969A (en) * 2005-09-26 2007-04-05 Fujifilm Corp Biosensor
JP2008086634A (en) * 2006-10-04 2008-04-17 Sharp Corp Washing apparatus using molecule detection device
JP2008538414A (en) * 2005-04-22 2008-10-23 富士レビオ株式会社 Sensor chip with bonded non-metallic particles including a metal coating
US20090098366A1 (en) * 2007-09-07 2009-04-16 Northwestern University Methods of coating surfaces with nanoparticles and nanoparticle coated surfaces
JP2010175454A (en) * 2009-01-30 2010-08-12 Yabegawa Denki Kogyo Kk Fluid transfer device, fluid transfer method, program, and recording medium
JP2011007725A (en) * 2009-06-29 2011-01-13 Kyushu Univ Method and apparatus for measuring residual agricultural chemical

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10265301A (en) * 1997-03-03 1998-10-06 Rohm & Haas Co Agrochemical composition
JPH116834A (en) * 1997-06-17 1999-01-12 Mitsubishi Chem Corp Sensor chip for biosensor, biosensor and manufacture thereof
JP2002357540A (en) * 2001-05-31 2002-12-13 Suzuki Motor Corp Plasmon sensor and method for measuring using the same
JP2006266746A (en) * 2005-03-22 2006-10-05 Fuji Photo Film Co Ltd Biosensor
JP2008538414A (en) * 2005-04-22 2008-10-23 富士レビオ株式会社 Sensor chip with bonded non-metallic particles including a metal coating
JP2007085969A (en) * 2005-09-26 2007-04-05 Fujifilm Corp Biosensor
JP2008086634A (en) * 2006-10-04 2008-04-17 Sharp Corp Washing apparatus using molecule detection device
US20090098366A1 (en) * 2007-09-07 2009-04-16 Northwestern University Methods of coating surfaces with nanoparticles and nanoparticle coated surfaces
JP2010175454A (en) * 2009-01-30 2010-08-12 Yabegawa Denki Kogyo Kk Fluid transfer device, fluid transfer method, program, and recording medium
JP2011007725A (en) * 2009-06-29 2011-01-13 Kyushu Univ Method and apparatus for measuring residual agricultural chemical

Similar Documents

Publication Publication Date Title
Ravindran et al. Recent advances in Surface Plasmon Resonance (SPR) biosensors for food analysis: A review
Dong et al. Analyte induced AuNPs aggregation enhanced surface plasmon resonance for sensitive detection of paraquat
Wang et al. Detection of copper ions in drinking water using the competitive adsorption of proteins
Wu et al. Rapid detection of melamine based on immunoassay using portable surface plasmon resonance biosensor
Liu et al. SPR quantitative analysis of direct detection of atrazine traces on Au-nanoparticles: nanoparticles size effect
Munawar et al. Molecularly imprinted polymer nanoparticle-based assay (MINA): application for fumonisin B1 determination
Zhou et al. Nanomechanical label-free detection of aflatoxin B1 using a microcantilever
Çimen et al. Patulin imprinted nanoparticles decorated surface plasmon resonance chips for patulin detection
CN104422682B (en) Raman spectroscopic apparatus, Raman spectroscopy and electronic equipment
Xu et al. Detection of Cryptosporidium parvum in buffer and in complex matrix using PEMC sensors at 5 oocysts mL− 1
Zheng et al. A review on rapid detection of modified quartz crystal microbalance sensors for food: Contamination, flavour and adulteration
Liu et al. Sensitive colorimetric detection of cyromazine in cucumber samples by using label-free gold nanoparticles and polythymine
Cakir A molecularly imprinted nanofilm‐based quartz crystal microbalance sensor for the real‐time detection of pirimicarb
Cao et al. Highly sensitive ‘naked-eye’colorimetric detection of thiourea using gold nanoparticles
Truong et al. Rapid detection of tebuconazole based on aptasensor and aggregation of silver nanoparticles
Çimen et al. Advanced plasmonic nanosensors for monitoring of environmental pollutants
Walekar et al. A novel colorimetric probe for highly selective recognition of Hg 2+ ions in aqueous media based on inducing the aggregation of CPB-capped AgNPs: accelerating direct detection for environmental analysis
Koukouvinos et al. Fast and sensitive determination of the fungicide carbendazim in fruit juices with an immunosensor based on white light reflectance spectroscopy
JP2005214863A (en) Method of measuring water and aqueous solution by ultraviolet ray
An et al. Fabrication of liquid crystal droplet patterns for monitoring aldehyde vapors
JP2013002817A (en) Method for detecting residual agricultural chemical and surface plasmon resonance sensor
Senn et al. Equilibrium-based sampler for determining Cu2+ concentrations in aquatic ecosystems
Razali et al. Optical fibre tip sensor coated with chitosan for lead ion detection
JP5250845B2 (en) Pesticide residue measuring method and apparatus
Yatabe et al. Fabrication of surface plasmon resonance sensor surface with control of the non-specific adsorption and affinity for the detection of 2, 4, 6-trinitrotoluene using an antifouling copolymer

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20140529

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A821

Effective date: 20140529

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20141217

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20150106

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20150512