6-磷酸葡萄糖脱氢酶 glucose-6-phosphate dehydrogenase Janbon 综合症 Janbon's syndrome PPB 浓度 parts per billion concentration pphm 浓度 parts per hundred million concentration PPH 浓度 parts per hundred concentration ppm 浓度 parts per million concentration 安全范围 safety range 安全试验法 innocuity test method