【正文】 the following item), and wet with about 5 ml of water. To this flask, mount a fraction collector and above that a cooling circulator. Introduce 10~20 ml of nitric acid and 10 ml of sulfuric acid into the fraction collector (3), and then turn cock A to gradually introduce the contents to the deposition flask. (If an extreme amount of bubbles are generated, it is advisable to let it sit overnight.) With cock B in the open position to allow condensation to circulate through the deposition flask, gradually heat up the flask. Once the intense reaction is pleted, close cock B and continue heating. Periodically open cock B to allow condensation to return from the fraction collector to the deposition flask. Rinse the cooling circulator with a small amount of water, add 5~10 ml of urea solution (urea 200 g/l), boil for a short time, and after cooling to below 60℃, add 2 ml of potassium permanganate solution (potassium permanganate 50 g/l), and boil again. At this time, if the permanganic acid color disappears, repeat the addition of potassium permanganate solution until the color remains for at least 10 minutes. After allowing to cool, add hydrochloride hydroxyamine (10 w/v%), reduce the excess potassium permanganate, and add water to bring solution to 250 ml for measurement.(1) 2port round bottom flask(2), (3) Cylindrical fraction funnels(4) Friedlich cooler(5) Bent tube(6) Cock A(7) Cock B c) Measurement procedure Reagents:1) Hg standard solution ( mg Hg/ml) : Refer to Cookbook Section 2, item 3 Preparing Standards2) Stannous chloride solution (10 w/v%) : Add 10 g of stannous chloride to 60 ml of sulfuric acid (sulfuric acid to water ratio 1:20), and while heating, mix to dissolve. After cooling, bring up to 100 ml using water. Procedure:1) The pretreated sample may be measured as it is.2) For the calibration curve, prepare standard solutions starting with incremental volumes between 2~12 ml of the Hg standard solution ( mg Hg/ml), then adding 20 ml of sulfuric acid (1+1), and bringing up to 250 ml using water. Measurement:Connect the MVU1A Mercury Vaporizer Unit to the atomic absorption spectrophotometer, and measure the sample. For details on operation of the MVU1A, refer to its acpanying documentation.Measurement wavelength: nmCalibration curve concentration range: 1~5 ng/mlMeasurement conditions:Lamp current: 4 mASlit width: nmLamp mode: BGCD2 Grains, Beans, and Potatoes Analysis MethodSame as analysis method described in Vegetables and Fruits Analysis Method Meat, and Fish Analysis MethodSame as analysis method described in Vegetables and Fruits Analysis Method Fats, Oils, and Dairy Products Analysis MethodReference materials:Health Testing Methods Commentary, Japan Pharmaceutical Society Publication, Kanehara Publishing Co., Foodstuffs Analysis Methods, Japan Foodstuffs Manufacturing Society, Foodstuffs Analysis Methods Editorial Commission Publication (Korin Co.) Sample Pretreatment a) Nitric acid, perchloric acid depositionThis is the same as the nitric acid, perchloric acid deposition of item a), however, perchloric acid and the sample often do not mix, preventing successful deposition. In such cases, use the procedure described in b) Ashing by drying. b) Ashing by dryingPlace 5~10 g of sample in a quartz beaker, add 1~3 ml of sulfuric acid, and gently heat on a hot plate at 120℃. After the ponents, which are volitilized at low temperatures are driven off, continue heating the sample until carbonization occurs. (At this time, if intense bubbling in the sample occurs, add ml of nitric acid.) Place this in an electric furnace, increase heat at a rate of 100℃ per hour, and at about 500℃ perform ashing over a period of several hours. If ashing is inplete, wet with 2~5 ml of 50% magnesium nitrate solution or nitric acid (1+1). After drying, continue ashing. Add 2~4 ml of water to the ash, and after drying, add 5 ml of hydrochloric acid to dissolve the salts. Use water to prepare fixed volumes of the measurement solution. Remarks:There is a possibility of volitilizing most of the elements, with Cd being volitilized during ashing above 500℃. If halogens are coexistent, As, Sb, Sn Zn, etc. will be volitilized. Heating above 550℃ will greatly reduce the element collection rate. Electrical Heating Atomic Absorption Method a) Target elementsCd, Pb, Cu, Fe, Zn b) Measurement procedureMeasurement is conducted using the following procedure. The lamp current value, and the slit width used are in accordance with Cookbook Section 4, item . ? Cd Reagents:Same as those described in item Electrical Heating Atomic Absorption Method, Cd. Procedure:Using 15 ml pretreated sample volumes, follow the procedure described in item Electrical Heating Atomic Absorption Method, Cd. Measurement:Same as described in item Electrical Heating Atomic Absorption Method, Cd. ? Pb Reagents:Same as those described in item Electrical Heating Atomic Absorption Method, Pb. Procedure:Using 15 ml pretreated sample volumes, follow the procedure described in item Electrical Heating Atomic Absorption Method, Pb. Measurement:Same as described in item Electrical Heating Atomic Absorption Method, Pb. ? Cu (direct quantitation of oil) Reagents:Cu standard solution ( mg Cu/ml): Prepare a 10 mg Cu/ml aqueous solution referring to Cookbook Section 2, item 3 Preparing Standards. Introduce 1 ml of this solution into a 50 ml volumetric flask, add 10 ml of methyl alcohol and mix well. Then bring up to volume using 4methyl2pentanone (MIBK), for the Cu standard solution ( mg Cu/ml). Or, measure out mg of the oily metallic standard reagent copper cyclohexylbutyric acid (molecular weight ), add 3 ml of xylene and 5 ml of 2ethylhexanoic acid. Gently heat to dissolve until it is clear. After cooling to room temperature, transfer the solution to a 100 ml volumetri